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Comments 130901 to 130950:

130901. Quietman at 11:09 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick But in fact the thinned crust is the northern end of Greenland (in the articles linked in this thread) and surrounding Arctic ocean and that is exactly where the largest glacial melt is AND IT IS FROM THE BOTTOM.
130902. Patrick 027 at 09:51 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        "My tectonic argument based on "the solar jerk" offers an explanation for this change while the IPCC argument does not." 1. But the 'IPCC argument' (also the argument of many others) may very well explain it... (more on that later) 2. How 'on earth' is the tectonic argument linked to the solar jerk? a. is it that tides, which may be correlated with solar jerk, are acting on either the geodynamo or tectonics or volcanism (all of which I strongly doubt (tidal variations weak, variations over relavent time periods weaker still), outside butterfly effects that take time and are not discernable as predictable links among individual causes and effects)? or b. that solar activity affects Earth's magnetic field, which of course does happen, BUT - I am very doubtful (with the same caveats as in a.) of any significant role of solar jerk or tides on the sun in changing solar activity, or of any significant link between changes in the outer core geodynamo and tectonics on the relavent timescales (mantle is very slow and reacts very slowly to changes in outer core convection), or of much effect, at least on the relavent timescales, that solar and space 'weather/climate' perturbations on Earth's magnetosphere and E-region dynamo could have on motions and magnetic field in the core, considering how much much much more massive the core is and how much more intense the field is in the core (yes, there is a lot of momentum and energy per unit mass in the magnetosphere, but still I expect much more total momentum and kinetic energy within the outer core), and also that, at least as far as I know, the strongest (relative?) perturbations of the magnetic field due to space weather occur at greater distances, where the field is even weaker still. ------------ Back to 1: Greenland article abstract (referenced in comment 66): the effect of meltwater is to lubricate the base of the glacier causing faster flow; sudden changes can occur as water flows. Effect may be limited. Nowhere does it state that the meltwater has increased due to geothermal heating - not that that's not a possibility but - without actual eruptions or sudden magma movement up through cracks, changes in geothermal heating must be slow - could it account for a significant change over only decades? How much heat would be necessary to account for the amount of water melting? Wouldn't there be some indication of volcanic activity (from a pattern of earthquakes (discernable from icequakes or quakes due to changing ice mass and isostatic adjustments??); sulfur concentration in meltwater outflow????)... I think this phenomenon of basal lubrication of the ice is not limited to the area where a underlying hotspot is thought to be. --- Arctic sea ice loss article: "Rising Arctic Storm Activity Sways Sea Ice, Climate ScienceDaily (Oct. 6, 2008)" http://www.sciencedaily.com/releases/2008/10/081006180815.htm What I got from that is: There was an expectation from climate theory ("derived from model results") that a warmer climate would lead to a northward shift in storm tracks and increased storminess in the arctic. This expectation has been verified from the observations. Observations also indicated that the changing circulation patterns have affected, through wind, the Arctic Ocean circulation, via movement of sea ice. Transport of sea ice: "The team found that the pace of sea ice movement along the Arctic Ocean's Transpolar Drift Stream from Siberia to the Atlantic Ocean accelerated in both summer and winter during the 55-year period." "Progressively stronger storms over the Transpolar Drift Stream forced sea ice to drift increasingly faster in a matter of hours after the onset of storms." (I'm not sure how similar this flow pattern is to the flow of ice associated with the 2007 circulation anomaly that pushed warmer air into Siberia - in that case, however, the atmospheric circulation pattern was not unprecedented, but resulted in record minimum ice because it was acting on top of an overall warmer atmosphere and thinner sea ice, etc. - because of ongoing global warming. There will be highs and lows; on top of an upward trends the highs and lows with both be higher, except potentially for the trend's effect on the shorter term variability itself.) Ocean mixing: "The moving sea ice forces the ocean to move which sets off significantly more mixing of the upper layers of the ocean than would occur without the "push" from the ice. The increased mixing of the ocean layer forces a greater degree of ocean convection, and instability that offers negative feedback to climate warming." That last part is potentially great! - that more CO2 might go into the oceans - BUT it is also potentially worrisome - will it speed up ice loss? Will it make it harder for new ice to form each winter as the fresher meltwater is mixed into the saltier water? - and of course because of the ice albedo feedback?
130903. Quietman at 05:14 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick In other words it would appear that the arctic is subject to some very unusual weather causing much of the problem for the past half century. The question now becomes, what caused the change in pattern. My tectonic argument based on "the solar jerk" offers an explanation for this change while the IPCC argument does not.
130904. Quietman at 05:08 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        correction: comment 257 (not 267).
130905. Quietman at 05:07 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        PS I posted a link in comment 267 in Arctic sea ice melt - natural or man-made? which is also applicable as a response.
130906. Quietman at 05:03 AM on 13 October 2008
        Climate sensitivity is low
        PPS I have a link posted here to Spencer's argument in comment 9.
130907. Quietman at 04:58 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick In the Greenland thread I have added an abstract that is applicable in answer.
130908. Quietman at 04:52 AM on 13 October 2008
        Climate sensitivity is low
        PS You apparently confuse ocean tides with tectonic tides.
130909. Quietman at 04:50 AM on 13 October 2008
        Climate sensitivity is low
        Patrick 1: His idea that CO2 sensitivity is low. 2.A: The concept that the solar wind does not have an effect on climate is wrong. 3: Tectonics
130910. Quietman at 04:44 AM on 13 October 2008
        Can animals and plants adapt to global warming?
        Mizimi Well, that paper *and any other paper, is an argument. The authors interpretation of his/her research, and as such is hypothetical. But I did find it interesting and as it relates to our prior discussions, thought you might find it of interest.
130911. Mizimi at 07:42 AM on 12 October 2008
        Can animals and plants adapt to global warming?
        QM: #59...thanks, very interesting. I have always regarded paleo-data as indicative of trends rather than absolutes because there seemed to be too many other factors that could influence the results that cannot be 'pinned down' with any exactitude. Now it seems the basis for one proxy is suspect; how many others might also be compromised?
130912. Patrick 027 at 04:53 AM on 12 October 2008
        Volcanoes emit more CO2 than humans
        Interesting article. Is meltwater perculating up from below to heat the ice? Geothermal heating would melt the bottom first; even with infinite thermal conductivity, the melting point of ice is lower at higher pressure. Depending on the thickness of the ice at that location, it might take considerable time for a change in heating to propogate upward. I think a majority is from AGW.
130913. Patrick 027 at 03:58 AM on 12 October 2008
        Climate sensitivity is low
        But 1. which of Spencer's arguments do you agree with? 2. -A. if the climate sensitivity is low than how does one explain the recent changes being caused by the minor changes in solar forcing or likely small forcing of changes in geomagnetism (?) or likely very very small forcing if any of submarine volcanic activity (volcanic aerosols already having been accounted for by IPCC etc.)? OR -B. what values do you expect when quantifying changes in non-TSI (and non-UV/TSI, as I expect that the UV enhancement associated with TSI is already accounted for (?)) solar forcing, geomagnetic forcing, tidal forcing, etc, in terms of radiative forcing or some equivalent or direct 'temperature' forcing by circulation changes in the ocean? For example, that article you referenced some time ago back in Science and Society regarding effects on transmissivity in clear air due to heliospheric current sheet crossing or 'Forbush' - whatever those things were (PS could you explain that to me?).
130914. chris at 23:42 PM on 11 October 2008
        CO2 measurements are suspect
        Re #3: Sure, the atmosphere is a relatively well-mixed medium. The specific point of interest is the locational variability of atmospheric CO2 levels. It only requires a brief perusal of the CO2 data from different sites around the world to show that CO2 mixes relatively quickly on an annual basis, even if there are very clear hemispheric differences in CO2 production and sequestration and so on. The relatively well-mixed nature of the atmosphere with respect to CO2 can be seen by observing the similarity in atmospheric CO2 levels at Manua Loa or averaged over the marine surface. i.e. compare the two data sets here: http://www.esrl.noaa.gov/gmd/ccgg/trends/ or look at an entirely seperate data set. For example the atmospheric CO2 measure at the South Pole: http://cdiac.ornl.gov/trends/co2/csiro/CSIROCO2SOUTHPOLE.JPG These differ by very small amounts (less than 1%) Your link is highlighting something quite different. This is a temporary "equator" that exists only during the monsoon season and that temporarily stops atmospheric mixing with respect to atmospheric pollutants. However if one considers the distribution of the atmosphere on an annually averaged basis as one does when considering atmospheric CO2 levels then the atmospheric is relatively well-mixed. That's not to say that macroscopic/particulate pollutants may not be concentrated over either their production sources or follow wind patterns. Nothern hemisphere skies are more polluted than Southern hemisphere skies on average. Thus brown clouds and other sulphurous aerosolic clouds may not disperse and mix so quickly. But if one considers the point of interest for this thread, namely the mixing of atmospheric CO2 with respect to obtaining valid atmospheric CO2 measures for monitoring short and long term changes, the atmosphere is a relatively well-mixed medium. The proof is in the pudding!
130915. Mizimi at 20:15 PM on 11 October 2008
        Can animals and plants adapt to global warming?
        "We take sequential steps towards switching our energy supplies towards the sustainable supplies that are clearly the only possible future of mankind." Totally agree: As I stated in another thread it is imperative we shift away from fossil fuels (and long term nuclear power) NOT because it will reduce CO2 emissions but because these fuels are finite. So we agree on that. That it also has the added effect of reducing CO2 emissions is a bonus (maybe).
130916. Quietman at 14:21 PM on 11 October 2008
        Climate sensitivity is low
        Patrick My argument is that the sensitivity is low (always has been) ie. I agree with Spencer. My agrument is for the earth itself combined with the sun are the primary drivers and while I do not actually argue against the Green House Effect, I feel that it is overstated. That the problem 1975-2007 was caused by high solar activity and vulcanism/tectonic activity. I have posted the most current articles in the volcano thread, the greenland glaciers thread and an abstract in the "Arctic sea ice melt - natural or man-made?" thread.
130917. Quietman at 10:50 AM on 11 October 2008
        CO2 measurements are suspect
        Re: "relatively well-mixed medium" SEE Earth's Air Divided by Chemical Equator By Andrea Thompson, Senior Writer posted: 30 September 2008 06:53 am ET
130918. Patrick 027 at 10:49 AM on 11 October 2008
        Climate sensitivity is low
        (refering again to your comment, 8, above) The part you would want to argue against starts on p. 3: "Attribution of Observed Changes Although confidence is high both that human activities have caused a positive radiative forcing and that the climate has actually changed, can we confidently link the two? This is the question of attribution: Are human activities primarily responsible for observed climate changes, or is it possible they result from some other cause, such as some natural forcing or simply spontaneous variability within the climate system?"
130919. chris at 10:48 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Re #58 that's excellent Quietman. One should always strive for truthful exposition... ..and the greenhouse effect really isn't difficult to comprehend..
130920. Patrick 027 at 10:42 AM on 11 October 2008
        Climate sensitivity is low
        Back to basics: Remind me again what it is that makes you doubtful of AGW? Because it occurs to me we're on the climate sensitivity thread now, and your position is not the climate is more stable but that it it is more stable specifically to greenhouse forcing and not to some various other factors... --- "Articles and Papers are much more appreciated as links (less opinion and more facts)" - understandable, but in matters of science (and some other things), good opinion writing includes reasoning and facts, and/or references to facts and reasoning. --- From comment 8 above: Your argument must be against the title of that section, "Drivers of Climate Change". Because climate sensitivity has nothing to do with how sure we are that it is human activity that is responsible for the recent changes in those things.
130921. chris at 10:38 AM on 11 October 2008
        Is Antarctic ice melting or growing?
        abstracts for articles cited in post #13: Sabine, CL et al. (2004) "The oceanic sink for anthropogenic CO2" Science 305, 367-371. "Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for similar to48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential." Feely, RA et al (2004) "Impact of anthropogenic CO2 on the CaCO3 system in the oceans" Science 305, 362-366. "Rising atmospheric carbon dioxide (CO2) concentrations over the past two centuries have led to greater CO2 uptake by the oceans. This acidification process has changed the saturation state of the oceans with respect to calcium carbonate (CaCO3) particles. Here we estimate the in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data, and we also discuss the future impacts of anthropogenic CO2 on CaCO3 shell forming species. CaCO3 dissolution rates, ranging from 0.003 to 1.2 micromoles per kilogram per year, are observed beginning near the aragonite saturation horizon. The total water column CaCO3 dissolution rate for the global oceans is approximately 0.5 +/- 0.2 petagrams of CaCO3-C per year, which is approximately 45 to 65% of the export production of CaCO3." Le Quere C et al (2007) "Saturation of the Southern Ocean CO2 sink due to recent climate change" 316, 1735-1738. :"Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale." Schuster U et al (2007) “A variable and decreasing sink for atmospheric CO2 in the North Atlantic” J. Geophys. Res. Oceans 112, art # C11006 “A time series of observations from merchant ships between the U. K. and the Caribbean is used to establish the variability of sea surface pCO(2) and air-to-sea flux from the mid-1990s to early 2000s. We show that the sink for atmospheric CO2 exhibits important interannual variability, which is in phase across large regions from year to year. Additionally, there has been an interdecadal decline, evident throughout the study region but especially significant in the northeast of the area covered, with the sink reducing > 50% from the mid-1990s to the period 2002-2005. A review of available observations suggests a large region of decrease covering much of the North Atlantic but excluding the western subtropical areas. We estimate that the uptake of the region between 20 degrees N and 65 degrees N declined by similar to 0.24 Pg C a(-1) from 1994/1995 to 2002-2005. Declining rates of wintertime mixing and ventilation between surface and subsurface waters due to increasing stratification, linked to variation in the North Atlantic Oscillation, are suggested as the main cause of the change. These are exacerbated by a contribution from the changing buffer capacity of the ocean water, as the carbon content of surface waters increases.” Nemani RR et al. (1999) “Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999” Science 300, 1560-1563. “Recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes. However, a comprehensive analysis of the impact of global climatic changes on vegetation productivity has not before been expressed in the context of variable limiting factors to plant growth. We present a global investigation of vegetation responses to climatic changes by analyzing 18 years (1982 to 1999) of both climatic data and satellite observations of vegetation activity. Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally. The largest increase was in tropical ecosystems. Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation.” Beedlow PA et al. (2004) “Rising atmospheric CO2 and carbon sequestration in forests” Fronteriers Ecol. Environ., 315-322. “Rising CO2 concentrations in the atmosphere could alter Earth's climate system, but it is thought that higher concentrations may improve plant growth through a process known as the "fertilization effect". Forests are an important part of the planet's carbon cycle, and sequester a substantial amount of the CO2 released into the atmosphere by human activities. Many people believe that the amount of carbon sequestered by forests will increase as CO2 concentrations rise. However, an increasing body of research suggests that the fertilization effect is limited by nutrients and air pollution, in addition to the well documented limitations posed by temperature and precipitation. This review suggests that existing forests are not likely to increase sequestration as atmospheric CO2 increases. It is imperative, therefore, that we manage forests to maximize carbon retention in above- and belowground biomass and conserve soil carbon.” Fung IY et al. (2005) “Evolution of carbon sinks in a changing climate” Proc. Natl. Acad. Sci. USA 102, 11201-11206. “Climate change is expected to influence the capacities of the land and oceans to act as repositories for anthropogenic CO2 and hence provide a feedback to climate change. A series of experiments with the National Center for Atmospheric Research-Climate System Model 1 coupled carbon-climate model shows that carbon sink strengths vary with the rate of fossil fuel emissions, so that carbon storage capacities of the land and oceans decrease and climate warming accelerates with faster CO2 emissions. Furthermore, there is a positive feedback between the carbon and climate systems, so that climate warming acts to increase the airborne fraction of anthropogenic CO2 and amplify the climate change itself. Globally, the amplification is small at the end of the 21st century in this model because of its low transient climate response and the near-cancellation between large regional changes in the hydrologic and ecosystem responses. Analysis of our results in the context of comparable models suggests that destabilization of the tropical land sink is qualitatively robust, although its degree is uncertain.” Field CB et al. (2007) “Feedbacks of terrestrial ecosystems to climate change“ Anu. Rev. Environment. Res. 32 , 1-29. “Most modeling studies on terrestrial feedbacks to warming over the twenty-first century imply that the net feedbacks are negative-that changes in ecosystems, on the whole, resistwarming, largely through ecosystem carbon storage. Although it is clear that potentially important mechanisms can lead to carbon storage, a number of less well-understood mechanisms, several of which are rarely or incompletely modeled, tend to diminish the negative feedbacks or lead to positive feedbacks. At high latitudes, negative feedbacks from forest expansion are likely to be largely or completely compensated by positive feedbacks from decreased albedo, increased carbon emissions from thawed permafrost, and increased wildfire. At low latitudes, negative feedbacks to warming will be decreased or eliminated, largely through direct human impacts. With modest warming, net feedbacks of terrestrial ecosystems to warming are likely to be negative in the tropics and positive at high latitudes. Larger amounts of warming will generally push the feedbacks toward the positive.” Kurz WA et al. (2008) “Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances?” Phil. Trans. Roy. Soc. B., 363, 2261. “To understand how boreal forest carbon (C) dynamics might respond to anticipated climatic changes, we must consider two important processes. First, projected climatic changes are expected to increase the frequency of fire and other natural disturbances that would change the forest age-class structure and reduce forest C stocks at the landscape level. Second, global change may result in increased net primary production (NPP). Could higher NPP offset anticipated C losses resulting from increased disturbances? We used the Carbon Budget Model of the Canadian Forest Sector to simulate rate changes in disturbance, growth and decomposition on a hypothetical boreal forest landscape and to explore the impacts of these changes on landscape-level forest C budgets. We found that significant increases in net ecosystem production (NEP) would be required to balance C losses from increased natural disturbance rates. Moreover, increases in NEP would have to be sustained over several decades and be widespread across the landscape. Increased NEP can only be realized when NPP is enhanced relative to heterotrophic respiration. This study indicates that boreal forest C stocks may decline as a result of climate change because it would be difficult for enhanced growth to offset C losses resulting from anticipated increases in disturbances.” Zhang XB (2007) "Detection of human influence on twentieth-century precipitation trends" Nature 448, 461-465. "Human influence on climate has been detected in surface air temperature(1-5), sea level pressure(6), free atmospheric temperature(7), tropopause height(8) and ocean heat content(9). Human-induced changes have not, however, previously been detected in precipitation at the global scale(10-12), partly because changes in precipitation in different regions cancel each other out and thereby reduce the strength of the global average signal(13-19). Models suggest that anthropogenic forcing should have caused a small increase in global mean precipitation and a latitudinal redistribution of precipitation, increasing precipitation at high latitudes, decreasing precipitation at sub-tropical latitudes(15,18,19), and possibly changing the distribution of precipitation within the tropics by shifting the position of the Intertropical Convergence Zone(20). Here we compare observed changes in land precipitation during the twentieth century averaged over latitudinal bands with changes simulated by fourteen climate models. We show that anthropogenic forcing has had a detectable influence on observed changes in average precipitation within latitudinal bands, and that these changes cannot be explained by internal climate variability or natural forcing. We estimate that anthropogenic forcing contributed significantly to observed increases in precipitation in the Northern Hemisphere mid-latitudes, drying in the Northern Hemisphere subtropics and tropics, and moistening in the Southern Hemisphere subtropics and deep tropics. The observed changes, which are larger than estimated from model simulations, may have already had significant effects on ecosystems, agriculture and human health in regions that are sensitive to changes in precipitation, such as the Sahel." Malhi Y et al. (2008) “Climate change, deforestation, and the fate of the Amazon” Science 319, 179-182. “The forest biome of Amazonia is one of Earth's greatest biological treasures and a major component of the Earth system. This century, it faces the dual threats of deforestation and stress from climate change. Here, we summarize some of the latest findings and thinking on these threats, explore the consequences for the forest ecosystem and its human residents, and outline options for the future of Amazonia. We also discuss the implications of new proposals to finance preservation of Amazonian forests.” Feeley KJ et al. (2007) “Decelerating growth in tropical forest trees” Ecology letters 10, 461-469. “The impacts of global change on tropical forests remain poorly understood. We examined changes in tree growth rates over the past two decades for all species occurring in large (50-ha) forest dynamics plots in Panama and Malaysia. Stem growth rates declined significantly at both forests regardless of initial size or organizational level (species, community or stand). Decreasing growth rates were widespread, occurring in 24-71% of species at Barro Colorado Island, Panama (BCI) and in 58-95% of species at Pasoh, Malaysia (depending on the sizes of stems included). Changes in growth were not consistently associated with initial growth rate, adult stature, or wood density. Changes in growth were significantly associated with regional climate changes: at both sites growth was negatively correlated with annual mean daily minimum temperatures, and at BCI growth was positively correlated with annual precipitation and number of rainfree days (a measure of relative insolation). While the underlying cause(s) of decelerating growth is still unresolved, these patterns strongly contradict the hypothesized pantropical increase in tree growth rates caused by carbon fertilization. Decelerating tree growth will have important economic and environmental implications.” Kurz WA et al. (2008) “Mountain pine beetle and forest carbon feedback to climate change “ Nature 452, 987-990. “The mountain pine beetle ( Dendroctonus ponderosae Hopkins, Coleoptera: Curculionidae, Scolytinae) is a native insect of the pine forests of western North America, and its populations periodically erupt into large- scale outbreaks(1-3). During outbreaks, the resulting widespread tree mortality reduces forest carbon uptake and increases future emissions from the decay of killed trees. The impacts of insects on forest carbon dynamics, however, are generally ignored in large- scale modelling analyses. The current outbreak in British Columbia, Canada, is an order of magnitude larger in area and severity than all previous recorded outbreaks(4). Here we estimate that the cumulative impact of the beetle outbreak in the affected region during 2000 - 2020 will be 270 megatonnes ( Mt) carbon ( or 36 g carbon m(-2) yr(-1) on average over 374,000 km 2 of forest). This impact converted the forest from a small net carbon sink to a large net carbon source both during and immediately after the outbreak. In the worst year, the impacts resulting from the beetle outbreak in British Columbia were equivalent to similar to 75% of the average annual direct forest fire emissions from all of Canada during 1959 - 1999. The resulting reduction in net primary production was of similar magnitude to increases observed during the 1980s and 1990s as a result of global change(5). Climate change has contributed to the unprecedented extent and severity of this outbreak(6). Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large- scale modelling analyses.” Piao S (et al) (2008) “Net carbon dioxide losses of northern ecosystems in response to autumn warming” Nature 451, 49-52. “The carbon balance of terrestrial ecosystems is particularly sensitive to climatic changes in autumn and spring1, 2, 3, 4, with spring and autumn temperatures over northern latitudes having risen by about 1.1 °C and 0.8 °C, respectively, over the past two decades5. A simultaneous greening trend has also been observed, characterized by a longer growing season and greater photosynthetic activity6, 7. These observations have led to speculation that spring and autumn warming could enhance carbon sequestration and extend the period of net carbon uptake in the future8. Here we analyse interannual variations in atmospheric carbon dioxide concentration data and ecosystem carbon dioxide fluxes. We find that atmospheric records from the past 20 years show a trend towards an earlier autumn-to-winter carbon dioxide build-up, suggesting a shorter net carbon uptake period. This trend cannot be explained by changes in atmospheric transport alone and, together with the ecosystem flux data, suggest increasing carbon losses in autumn. We use a process-based terrestrial biosphere model and satellite vegetation greenness index observations to investigate further the observed seasonal response of northern ecosystems to autumnal warming. We find that both photosynthesis and respiration increase during autumn warming, but the increase in respiration is greater. In contrast, warming increases photosynthesis more than respiration in spring. Our simulations and observations indicate that northern terrestrial ecosystems may currently lose carbon dioxide in response to autumn warming, with a sensitivity of about 0.2 PgC °C-1, offsetting 90% of the increased carbon dioxide uptake during spring. If future autumn warming occurs at a faster rate than in spring, the ability of northern ecosystems to sequester carbon may be diminished earlier than previously suggested9, 10.” Ciais P et al. (2005) Europe-wide reduction in primary productivity caused by the heat and drought in 2003” Nature 437, 529-533. “Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration(1,2). But although severe regional heatwaves may become more frequent in a changing climate(3,4), their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country- level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model(5) to assess continental- scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide ( 0.5 Pg Cyr(-1)) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration(6). Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon- climate feedbacks already anticipated in the tropics and at high latitudes(1,2).” Lotsch A et al. (2005) “Response of terrestrial ecosystems to recent Northern Hemispheric drought” Geophys. Res. Lett. : 32, art #L06705. “Satellite normalized difference vegetation index (NDVI) observations reveal large and geographically extensive decreases in vegetation activity in Eurasia and North America between 1999 and 2002. In 2001, 73% of central southwest Asia exhibited NDVI anomalies that were more than one standard deviation below 21-year average conditions, and in 2002, fully 95% of North America exhibited below-average NDVI. This episode of large-scale vegetation browning coincided with a prolonged period of below-normal precipitation in the Northern Hemisphere, which limited moisture availability for plant growth. Spatio-temporal dynamics of NDVI, precipitation, and sea surface temperature data reveal that synchronous patterns of ocean circulation anomalies in the Pacific, Atlantic, and Indo-Pacific are strongly correlated with observed joint variability in NDVI and precipitation in the Northern Hemisphere during this period.” Olsson L (2005) “A recent greening of the Sahel — trends, patterns and potential causes” J. of Arid Environ. 63, 556–566. "For the last four decades there has been sustained scientific interest in contemporary environmental change in the Sahel (the southern fringe of the Sahara). It suffered several devastating droughts and famines between the late 1960s and early 1990s. Speculation about the climatology of these droughts is unresolved, as is speculation about the effects of land clearance on rainfall and about land degradation in this zone. However, recent findings suggest a consistent trend of increasing vegetation greenness in much of the region. Increasing rainfall over the last few years is certainly one reason, but does not fully explain the change. Other factors, such as land use change and migration, may also contribute. This study investigates the nature of a secular vegetation trend across the Sahel and discusses several potential causative factors."
130922. Quietman at 10:30 AM on 11 October 2008
        Arctic sea ice melt - natural or man-made?
        Rising Arctic Storm Activity Sways Sea Ice, Climate ScienceDaily (Oct. 6, 2008) — A new NASA study shows that the rising frequency and intensity of arctic storms over the last half century, attributed to progressively warmer waters, directly provoked acceleration of the rate of arctic sea ice drift, long considered by scientists as a bellwether of climate change.
130923. Quietman at 10:27 AM on 11 October 2008
        Volcanoes emit more CO2 than humans
        Satellite Data Reveals Extreme Summer Snowmelt In Northern Greenland ScienceDaily (Oct. 10, 2008) — The northern part of the Greenland ice sheet experienced extreme snowmelt during the summer of 2008, with large portions of the area subject to record melting days, according to Dr. Marco Tedesco, Assistant Professor of Earth & Atmospheric Sciences at The City College of New York (CCNY), and colleagues.
130924. Patrick 027 at 10:26 AM on 11 October 2008
        Climate sensitivity is low
        

        More on radiation transfer within and through the atmosphere: Regional Climate Projections (25,26*,55**,56**,57**,58**,83***,85***,104,110****,111,146,191) asterisks pertain more to visualizing greenhouse effect physics  (171-173,174*,175,176*,180~,181~,184*****,189****,192***,193,194,203,214,215,218 (*** near bottom),232**,235,238,245,246) Real Climate (105**,144**,168 (LTE) ,170** (and LTE),172 (mainly LTE),192**,229**,241**(ext),251***(BB),252***(BB),261**(ext),274*,275*,285*,289) LTE = local thermodynamic equilibrium BB = fundamentals of blackbody radiation and radiative physics ext = what happens in extreme scenarios

        Moderator Response:

        [RH] Fixed links that were breaking page formatting.

130925. chris at 10:24 AM on 11 October 2008
        Is Antarctic ice melting or growing?
        DB2 I suspect that we might agree that there are two essential considerations with respect to enhanced CO2 concentrations (and its consequences) on plant growth: 1. The ability of the terrestrial environment to sequester CO2 in a world with rapidly growing atmospheric CO2 concentrations. Will enhanced plant growth and thus carbon sequestration protect us significantly against rising atmospheric CO2 and its consequences? 2. The effect of raised atmospheric CO2 levels on agricultural production. This is really an entirely separate consideration compared to (#1). In my understanding the prognosis is negative in each of these. Here’s what the science seems to say (I’ve put all the citations at the bottom of the post and dumped the abstracts in a separate post below where it’s eminently ignorable!): 1. The terrestrial environment is not going to help us out with respect to significant carbon sequestration. It will do to a small extent for a while but this is more likely to lead us towards a false sense of optimism, and any small initial benefits are unsustainable. Here’s why: The terrestrial environment absorbs a very small amount of our CO2 emissions. Something around 10%. Around 40-50% of our emissions are currently absorbed by the oceans [1,2]. If we’re interested in mitigating the effects of raised atmospheric CO2 levels by sequestration from the atmosphere, it’s to the oceans we should look. Unfortunately it’s expected that the abilitiy of the oceans to sequester atmospheric CO2 will reduce. This may already to be happening [3,4]. 2. Whatever we might think, hope or surmise about the possibility of enhanced sequestration of carbon, the real world observations aren’t encouraging. Whether or not the terrestrial environment has shown enhanced overall carbon sequestration in recent decades ([5]; i.e. the Nemani paper that you cited in your post #8, for example; and there is good evidence that the Amazon has experienced a net increase in productivity over the last couple of decades, as has parts of China and India), this has obviously not had much of an effect on the rapidly increasing concentrations of atmospheric CO2, as direct inspection of the atmospheric Co2 record makes clear. 3. Any enhanced sequestration of carbon into the terrestrial environment is unlikely to be sustainable [6,7,8,9]. Firstly, because there is only so much room for plant growth, and so much potential for carbon sequestration unless we embark on an enormous reforestation programme (an excellent idea btw...at least we should be protecting our forests!). Secondly, because as the earth continues to warm, and the water-restricted regions extend from the central latitudes, more and more of the terrestrial environment will find itself in the water-limited regions. At present the increased drought that results from the warming of the last several decades is restricted to the region from around 0 -30 o North [10]. Apart from the extreme Northern regions where drying has started [11], the Amazon has seen either no drying or enhanced precipitation [11]. The expectation is that this so-far acceptable situation will not continue in a warming world…the Amazon is threatened with a continued shift in the drying zone southwards as warming continues. 4. The effects of warming are already apparent, and it doesn’t take a lot of warming to turn net carbon sinks into net carbon sources. If one moves out of the Amazon below the drying zone, and moves a bit northwards into the drying zone one observes loss of primary production in rainforests in Central America and Malaysia [12], the loss of primary production in Canadian forests under the combined/linked influence of warming and infestation [13], observations already of a trend towards net carbon loss in Northern ecosystems [14], and large decreases in N. hemisphere primary productivity in response to periods of anomalous heat (which in the future are likely to become increasingly less anomalous) [15,16]. While regions of China and India have seen enhanced plant growth in recent decades, this is unlikely to be sustainable into the future. 5. The effects on agricultural production are rather as I indicated in my post above. In addition to the papers I cited, the expectation is that agricultural production will decrease in a warming world without enormous efforts and costs to maintain this. Costs are unlikely to be affordable by many especially in the large belt of the world in the drying region encompassing the latitude belt from around 0o to 30 oN. The paper that you cited on the Sahel [17] is not as encouraging as one might think. As the authors indicate, some of the enhanced growth is due to enhanced precipitation in recent years; however much of it is unexplained, and as far as food production is concerned only two countries in the region have seen enhanced production (Burkino Faso and Mali). The authors consider that some of the greening might be due to war and the migration away from rural areas. If enhanced greening is the result of the recolonisation of neglected agricultural land by vegetation that’s not particularly positive with respect to the prospects for agricultural production. As the authors state “The vast belt of significantly increasing vegetation across the central Sudan corresponds to a large extent to provinces with large numbers of internally displaced people”. [1] Sabine, CL et al. (2004) "The oceanic sink for anthropogenic CO2" Science 305, 367-371. [2] Feely, RA et al (2004) "Impact of anthropogenic CO2 on the CaCO3 system in the oceans" Science 305, 362-366. [3] Le Quere C et al (2007) "Saturation of the Southern Ocean CO2 sink due to recent climate change" 316, 1735-1738. [4] Schuster U et al (2007) “A variable and decreasing sink for atmospheric CO2 in the North Atlantic” J. Geophys. Res. Oceans 112, art # C11006 [5] Nemani RR et al. (1999) “Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999” Science 300, 1560-1563. [6] Beedlow PA et al. (2004) “Rising atmospheric CO2 and carbon sequestration in forests” Fronteriers Ecol. Environ., 315-322. [7] Fung IY et al. (2005) “Evolution of carbon sinks in a changing climate” Proc. Natl. Acad. Sci. USA 102, 11201-11206. [8] Field CB et al. (2007) “Feedbacks of terrestrial ecosystems to climate change“ Annu. Rev. Environment. Res. 32 , 1-29. [9] Kurz WA et al. (2008) “Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances?” Phil. Trans. Roy. Soc. B., 363, 2261. [10] Zhang XB (2007) "Detection of human influence on twentieth-century precipitation trends" Nature 448, 461-465. [11] Malhi Y et al. (2008) “Climate change, deforestation, and the fate of the Amazon” Science 319, 179-182. [12] Feeley KJ et al. (2007) “Decelerating growth in tropical forest trees” Ecology letters 10, 461-469. [13] Kurz WA et al. (2008) “Mountain pine beetle and forest carbon feedback to climate change “ Nature 452, 987-990. [14] Piao S (et al) (2008) “Net carbon dioxide losses of northern ecosystems in response to autumn warming” Nature 451, 49-52. [15] Ciais P et al. (2005) Europe-wide reduction in primary productivity caused by the heat and drought in 2003” Nature 437, 529-533. [16] Lotsch A et al. (2005) “Response of terrestrial ecosystems to recent Northern Hemispheric drought” Geophys. Res. Lett. : 32, art #L06705. [17] Olsson L (2005) “A recent greening of the Sahel — trends, patterns and potential causes” J. of Arid Environ. 63, 556–566.
130926. Quietman at 10:17 AM on 11 October 2008
        Models are unreliable
        New Study Increases Concerns About Climate Model Reliability ScienceDaily (Dec. 12, 2007) — A new study comparing the composite output of 22 leading global climate models with actual climate data finds that the models do an unsatisfactory job of mimicking climate change in key portions of the atmosphere.
130927. Quietman at 10:10 AM on 11 October 2008
        Greenland is gaining ice
        However: Science 4 July 2008: Vol. 321. no. 5885, pp. 111 - 113 DOI: 10.1126/science.1158540 Reports Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet R. S. W. van de Wal,* W. Boot, M. R. van den Broeke, C. J. P. P. Smeets, C. H. Reijmer, J. J. A. Donker, J. Oerlemans Continuous Global Positioning System observations reveal rapid and large ice velocity fluctuations in the western ablation zone of the Greenland Ice Sheet. Within days, ice velocity reacts to increased meltwater production and increases by a factor of 4. Such a response is much stronger and much faster than previously reported. Over a longer period of 17 years, annual ice velocities have decreased slightly, which suggests that the englacial hydraulic system adjusts constantly to the variable meltwater input, which results in a more or less constant ice flux over the years. The positive-feedback mechanism between melt rate and ice velocity appears to be a seasonal process that may have only a limited effect on the response of the ice sheet to climate warming over the next decades. Institute for Marine and Atmospheric research Utrecht, Utrecht University, Netherlands.
130928. Quietman at 10:01 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Mizimi Jast an FYI: Global synchronous changes in the carbon isotopic composition of carbonate sediments unrelated to changes in the global carbon cycle Peter K. Swart Department of Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 Edited by John M. Hayes, Woods Hole Oceanographic Institution, Woods Hole, MA, and approved July 24, 2008 (received for review April 15, 2008) Abstract The carbon isotopic (δ13C) composition of bulk carbonate sediments deposited off the margins of four carbonate platforms/ramp systems (Bahamas, Maldives, Queensland Plateau, and Great Australian Bight) show synchronous changes over the past 0 to 10 million years. However, these variations are different from the established global pattern in the δ13C measured in the open oceans over the same time period. For example, from 10 Ma to the present, the δ13C of open oceanic carbonate has decreased, whereas platform margin sediments analyzed here show an increase. It is suggested that the δ13C patterns in the marginal platform deposits are produced through admixing of aragonite-rich sediments, which have relatively positive δ13C values, with pelagic materials, which have lower δ13C values. As the more isotopically positive shallow-water carbonate sediments are only produced when the platforms are flooded, there is a connection between changes in global sea level and the δ13C of sediments in marginal settings. These data indicate that globally synchronous changes in δ13C can take place that are completely unrelated to variations in the global carbon cycle. Fluctuations in the δ13C of carbonate sediments measured during previous geological periods may also be subject to similar processes, and global synchroniety of δ13C can no longer necessarily be considered an indicator that such changes are related to, or caused by, variations in the burial of organic carbon. Inferences regarding the interpretation of changes in the cycling of organic carbon derived from δ13C records should be reconsidered in light of the findings presented here.
130929. Quietman at 09:42 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        chris Of course, how could I have been so stupid as not to see the light. Amen.
130930. chris at 08:32 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Re #56 That's not really true Mizimi and your argument has a self-defeating element to it. ONE: If one addresses the fossil fuel reserves in relation to estimated recoverable sources rather than proven reserves (the values of which continually increase as new reserves are found), there is a whole lot more fossil fuel with potential for mining. Atmospheric CO2 levels can go way higher than 500 ppm. The US department of energy (DOE) estimate, that the proved[***] reserves for oil and gas are: 1.14-1.33 trillion barrels of oil (equivalent to around 43 years worth) 6.2-6.4 trillion cubic feet of natural gas (equivalent to around 160 years worth) and estimated recoverable coal (anthracite, bituminous, lignite and subbituminous): 1 million, million short tons of coal (equivalent to more than 400 years worth). oil and gas (Aug 27th 2008 update): http://www.eia.doe.gov/emeu/international/reserves.xls coal: http://www.eia.doe.gov/pub/international/iea2005/table82.xls [***] Proved reserves are estimated quantities that analysis of geologic and engineering data demonstrates with reasonable certainty are recoverable under existing economic and operating conditions. Burning all of that fossil fuel will take atmospheric CO2 levels way, way above 500 ppm. We're talking more like 1200-1500 ppm TWO: the obvious solution. Your approach to this is extraordinary. You're seemingly totally accepting of widescale extinction (you and Quietman consider this is just "natural")...you suggest that the "likely future for" your "grandchildren is one of energy poverty" and that "the most likely candidate for an extinction event is "Homo Sapiens Civilis""...and yet you consider that it's worthwhile propagandising against the science that might (and is, happily) help us in addressing these rather obvious problems. There is a solution to your grandchildrens "energy poverty" and your suggestion of "Homo Sapiens Civilis potential "extinction" (you suggest they're the "most likely candidate"). It's to address the problem with a bit of maturity and rationality. We take sequential steps towards switching our energy supplies towards the sustainable supplies that are clearly the only possible future of mankind. However difficult that may be, it solves all of the problems highlighted. Your grandchildren escape "energy poverty"...your "Homo Sapiens Civilis" escape "extinction"....the natural world avoids a wide-scale extinction (see top post by Barry Brook)...our descendants avoid massive, debilitating, and extraordinarily costly sea level rise...ocean acidification....enhanced drought in the central latitudes...enhanced extreme weather events....irrigation supply catastrophes and so on.... I have a feeling we might all be somewhere approaching the same wavelength on this!
130931. Mizimi at 05:44 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        #46....Abstract: "Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2 degrees C by 2050 to 2100," et seq.posts. One major problem the AGW argument has ( and one of the primary reasons I remain sanguine about the whole affair) is that of time. They seem to assume that there are endless supplies of fossil fuels just waiting to be used, and then make forward projections on that assumption. Recoverable coal reserves are currently estimated at 147 years supply based on current consumption. Oil production has peaked and estimated reserves = 40 years supply. Natural gas estimated reserves = 65 years. ( not including clathrates). So the likely future for my grandchildren ( who may live to see 2100, some 92 years away) is one of energy poverty - and potential devastating decline in civilisation (accelerated by 'energy wars'). So the most likely candidate for an extinction event is "Homo Sapiens Civilis" http://www.worldcoal.org/pages/content/index.asp?PageID=188 http://www.eia.doe.gov/emeu/international/reserves.html http://www.eia.doe.gov/basics/quickoil.html
130932. chris at 05:14 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Re #53 Quietman, it’s worth highlighting the essential difference between your (and Mizimi’s, apparently) and my view on extinctions in relation to global warming. I’ll outline this again, since according to your post #53 you don’t seem to understand what I am talking about. Both you and Mizimi dissociate yourself from the situation as it stands, discount the possibility that we might consider our role in potential species extinctions and what the consequences might be for our and our near descendents welfare, and consider this from the point of view of a rather carefree observer. Your attitudes are similar in nature to those that might enter a discussion on the steps we might take to reduce deaths from automobile accidents, by pointing out that it’s in the very nature of things that collide at high speeds that they become deformed from impacts, but that this is just a general law of physics, and we might actually find it “interesting” to observe these dispassionately. It’s difficult to come to any other conclusion based on your continual turning of the subject of this thread towards rather “potted” concepts of evolutionary "theory". You (and Mizimi) consider the situation to be “natural”, that things are just following “ the rule in evolution”, “evolution must take it’s course” and so on. Your comments in particular are extraordinary, since you seem to consider “extinction cycles” rather excellent, to the point of cheerleading for an extinction. And yet you seem oblivious to the evidence that (i) major extinction events are actually not that wonderful in practice to those involved and (ii) that the “interesting” consequences that you envisage take many hundreds of thousands or millions of years. Since the concerns of mature and far-sighted individuals is for the immediate future (the several decades to come), extending possibly towards events that might be set in motion now to impact our descendants of the coming century or two, it seems astonishing that someone would consider that it will be rather excellent to pursue a relatively near future of large scale extinction in the cerebral delight of considering what a wonderful evolutionary recovery might accrue a million years from now. A rather apocalyptic vision, in fact. There are surely some rational skeptical viewpoints with respect to the expectation of wide-scale warming-induced extinctions resulting from man-made enhancement of the earth’s greenhouse effect. One might have the view either that it’s not really warming (difficult to defend), that it won’t warm that much in the future (likewise difficult to defend, ‘though pretending that the greenhouse effect doesn’t exist certainly helps!), or that the warming won’t actually be a problem for species on a wide scale. In my opinion none of these is a comforting possibility when considered in the light of the evidence in the real world either as it exists now, or from paleo-analysis of events in the deep past. But the notion that we wash our hands of the entire business, and pursue self-defeating scenarios without consideration of their consequences, other than in the light of a cerebral interest in extinctions (one of your “favorite studies”), seems extraordinarily perverse if not downright repellent…
130933. chris at 04:25 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Re #53 Quietman I'm afraid that's nonsense. Making stuff up and telling untruths is not skepticism. On untruth: I cited some papers on the relationship between paleodata identifying cold (warm) spells in the deep past and data that identified contemporaneous lowered (raised) atmospheric CO2 levels. You make the ill-informed assertion (your post #43) that "The cited papers assumes that the sensitivity is as the IPCC hypothesizes." But of course they do nothing of the sort, as simple perusal of the papers would establish. Even 'though you clearly have no idea what you are talking about with respect to this work you chose to pursue that falsehood in your post #47. What is to be gained by making up stuff that simply isn't true Quietman? If pursuing an agenda position requires you to misrepresent the work of others, perhaps you should consider whether your agenda position is worth it! On your odd comments about the greenhouse effect: It really does seem that you don't believe in the greenhouse effect, which is rather astonishing. Your schoolboy notions about “open” and “closed” systems are rather dismal (happily a schoolboy would be unlikely to pursue such a level of ignorance!). Is the earth an open or a closed system Quietman? If not, what might a closed system encompass with respect to the solar system, for example? And why would anyone possibly attempt to pursue the notion that an obvious, well-characterized and undeniable phenomenon doesn’t exactly exist by using fallacious arguments based on semantics? In fact the solar system might be considered a closed system, and one could then ponder the distribution of the thermal energy arising from the powerhouse that sits at its “centre”. What happens to all that radiated heat, blasted into the sun’s surrounds in the form of radiation that covers large parts of the visible, UV, and IR regions of the spectrum? How about the earth? We know the size of the sun, its surface temperature, the size of the earth and can estimate a value for the earth’s overall albedo. This allows us to calculate the temperature of a “naked” earth bathed in the solar radiation. This was first done by Fournier in the early 19th century. The earth should be around 255K (-18 oC). We can do the same calculation now. Same result. We know this simple analysis is effective since we can apply it to other planets and determine their “black body” temperature. Spectroscopic analysis of the true planetary temperature is revealing of its atmospheric composition, and we can explore this further using spectroscopic detection of the atmospheric gases. So why is the earth so warm (a cozy ~288 K)? Already in the 19th century that was identified. It’s our atmospheric water vapour and carbon dioxide. These molecules (unlike the symmetric O2 and N2 that make up the vast proportion of our atmosphere) absorb infra-red radiation emitted from the earth following insolation, and reradiate the energy (or “bump” into surrounding atmospheric gas molecules increasing their kinetic energy, which, as you should know, is effectively equivalent to their “temperature”). How do we know that CO2 and water vapour absorb and re-radiate infra-red radiation? Because we can measure it directly. It’s a no-brainer Quietman. The greenhouse effect exists. The question then relates to the amount that the greenhouse efect warms us (e.g. the "climate sensitivity"). Since we know the infra-red absorptive properties of CO2 (and water vapour) we can calculate the radiative forcing that results in increasing the atmospheric CO2 concentration, for example. This forcing results in the retention of excess thermal energy by the suppression of the ability of surface infra-red to radiate freely into space. It’s a little like lying in your chilly bed in February, and putting a blanket on top of you. Is that a “closed system” Quietman? Not really. And yet you get warmer (else you’d probably not bother). The suppression of the escape of radiation into the surrounds (your bedroom or cold empty space) results in a shift in the equilibrium temperature of the surface of the body “protected” by the thermal “blanket” to a higher value. The full effect of raising atmospheric CO2 levels on the earth’s temperature is realized by feedbacks. The most important one is the rise in atmospheric water vapour concentrations as the atmosphere warms under the influence of enhanced CO2. Does this increase in atmospheric water vapour in the atmosphere actually occur? Yes it does Quietman. How do we know? Because we can measure it. And so on.
130934. Quietman at 23:51 PM on 10 October 2008
        Can animals and plants adapt to global warming?
        chris Evolution and extinction go hand in hand, I never changed the subject. As to the rest of your comment I have no idea what you are talking about. On my "untruth", Green house is a known effect in a closed system, an unknown in an open system, if more than a hypothesis in an open system then prove it. A theory requires proof, not consensus. Show me the physical evidence that it works they way you indicate.
130935. chris at 22:21 PM on 10 October 2008
        Evaporating the water vapor argument
        re #15 "Heat in = Heat out, No?" No. Heat in doesn't equal heat out. With enhanced greenhouse forcing under constant insolation, Heat in is greater than Heat out (Heat in > Heat out)...in other words it gets warmer, until the effects of the enhanced forcing reach equilibrium. At that point Heat in does equal Heat out, but the system retains a greater amount of thermal energy. The world is warmer. That's not difficult to understand. And as we all know rather well, since simple physics, theory, simulation and real world measurements indicates this to be the case, a warmer atmosphere supports a larger water vapour concentration, and so as the earth warms under the influence of enhanced atmospheric CO2 concentrations, this warming results in an enhanced water vapour concentration. Since water vapour is itself a very strong greenhouse gas, this results in feedback warming. So enhanced atmospheric CO2 "adds" thermal energy (warmth) to the earth's climate system, and the resultant enhanced water vapour concentrations "adds" additional thermal energy (warmth). So it really requires rather awesome bottom-squirming semantic quibbling to pursue the fallacy that enhanced greenhouse gas concentrations "cannot "add" anything"... ..or are you suggesting that the greenhouse effect doesn't exist?!
130936. chris at 20:21 PM on 10 October 2008
        It's the ocean
        Re #3 Quietman which maps are you referring to (in relation to your statement about warming on ridge lines)?
130937. Patrick 027 at 15:08 PM on 10 October 2008
        Climate sensitivity is low
        Last comment posted before seeing your last comment - "John allows links and actually prefers hyperlinks. But he has asked us to keep the discussion pertinent to the thread and not post "lists of links" so I try to break up my comments for readability." Duly noted. (I know I wandered a bit from 'Volcanoes' in the prior segment of discussion... part of it was centered on tides and that naturally expanded to other things...) "PS I looked at your remark on THERMODYNAMICS but skipped"..." Articles and Papers are much more appreciated as links (less opinion and more facts)." That's fine - the rest of my RealClimate comments I listed above were for just in case you were interested (many covering topics we discussed back at Science and Society, but each time I write something I don't do it the exact same way, so... etc.). I did have some RC comments on radiative physics in the atmosphere in particular and when I finnish tracking those down I will post a reference to those and ONLY those.
130938. Patrick 027 at 14:53 PM on 10 October 2008
        Climate sensitivity is low
        I decided to repost some comments at http://blogs.abcnews.com/scienceandsociety/2008/07/global-warming.html#comments - The comments about Monckton's paper, at least one (big) one of which was deleted from that website, hence this repost: --- MORE ARTFULLY WRITTEN CRITIQUES FOUND AT RealClimate: "Once more unto the bray", DELTOID: "Monckton's Triple Counting" MONCKTON'S PAPER "Climate Sensitivity Reconsidered": (Monckton has a prior record of demonstrating an apparent lack of accuracy in this subject matter.) INTERNAL VARIABILITY --"[G]LOBALLY-AVERAGED land and sea surface absolute temperature TS has not risen since 1998 (Hadley Center; US National Climatic Data Center; University of Alabama at Huntsville; etc.). For almost seven years, TS may even have fallen (Figure 1). There may be no new peak until 2015 (Keenlysideet al., 2008)." "The models heavily relied upon by the Intergovernmental Panel on Climate Change (IPCC) had not projected this multidecadal stasis in “global warming”; " Of course they haven't, because: 1.the timing of specific cases of such short term interannual to decadal variability is not so important to longer term climate trends, and even to the extent that models may reproduce the general characteristics of variability, such variations get averaged to near-zero in combining multiple runs of models. 2. 1998 was extra warm because of the El Nino. There will be, in any given period of sufficient length, some number of warmer years and cooler years relative to any longer trend. One can't conclude there is/has been a 'stasis', especially a 'multidecadal stasis', in the warming. ________ --"nor (until trained ex post facto) the fall in TS from 1940-1975;" what 'trained'? --"nor 50 years’ cooling in Antarctica (Doran et al., 2002)" Ozone hole has a regional effect there, and I can't take Monckton's word for it that the Antarctic has cooled for as long as 50 years. Anyway, at least a part of it have warmed. --"and the Arctic (Soon, 2005);" The arctic has been warming. --"nor the onset, duration, or intensity of the Madden-Julian intraseasonal oscillation, "... Models can't reproduce all aspects of internal variability yet. So they aren't perfect. That doesn't invalidate all of what they can do. --"(oceanic oscillations which, on their own, may account for all of the observed warmings and coolings over the past half-century: Tsoniset al., 2007);" Then where has all the warming from greenhouse gases gone? The rest of that paragraph - short term variability, so what. Medieval Warm Period - perhaps mainly a Northern Hemisphere or European phenomenon; not so big globally. Warming on other planets - Pluto's temperature response to the eccentricity in it's orbit lags the forcing due to thermal inertia; what warming on Jupiter? (recent circulation changes may be an internal variability - which, I believe, was predicted by a model!); Mars' albedo is affected by Dust storms, and is the warming global? Earth's climate history is understood generally better than those of other planets. Solar Grand Maximum - is it grand enough? ________ Reproduction of Hansen's graph from 1988: - it's a mischaracterization; for the emissions scenario we've most closely followed, the temperatures have followed quite closely thus far. ________ CLIMATE VS WEATHER --"The climate is “a complex, non-linear, chaotic object” that defies long-run prediction of its future states (IPCC, 2001), unless the initial state of its millions of variables is known to a precision that is in practice unattainable," He's confusing climate with weather and ignoring different timescales. --"combined with a heavy reliance upon computer models unskilled even in short-term projection, with initial values of key variables unmeasurable and unknown, with advancement of multiple, untestable"" so what? This isn't weather prediction. ________ DEFINITIONS --"consequent increase in aggregate forcing (from Eqn. 3 below) of ~0.26 W m–2, or <1%. That is one-twentieth of the value stated by the IPCC. The absence of any definition of “radiative forcing” in the 2007 Summary led many to believe that the aggregate (as opposed to anthropogenic) effect of CO2 on TS had increased by 20% in 10 years. The IPCC – despite requests for correction – retained this confusing statement in its report." Anyone who's confused could have looked at the other numbers given by the IPCC to figure it out. In the context of climate CHANGE radiative forcing is often discussed as the CHANGE from some reference level. ________ --"non-Popper-falsifiable theories," Give it time and we'll see. So far things are happenning that have been expected. But for the purposes of public policy, this could also be seen to a degree as an application of scientific knowledge already gained - we know A, B, C, so we expect if we do D we'll get E. etc. --"and, above all, with the now-prolonged failure of TS to rise as predicted (Figures 1, 2), raise questions about the reliability and hence policy-relevance of the IPCC’s central projections."" There has not been such a prolonged failure. We expect a few bumps and dips. ________ feedbacks: Unless otherwise specified, the climate sensitivity to radiative forcing by a doubling (or whatever change) of CO2 is based on the radiative forcing of the doubling of CO2, whatever the source of CO2 is, including feedbacks. --"For this and other reasons, it is not possible to obtain climate sensitivity numerically using general-circulation models: for, as Akasofu (2008) has pointed out, climate sensitivity must be an input to any such model, not an output from it." Nonsense. Climate sensitivity is input only implicit - it is the evaluation of model output that can determine explicitly what the sensitivity is. ________ Radiative forcing: This is basic physics; if the amount and the radiative properties are known, radiative forcing can be calculated. For CO2 and generally other gases, both are known quite well. Some things about clouds are known, but the feedbacks from changes in the amount of different types of cloud in different places is a source of uncertainty. In so far as external radiative forcing, I think aerosols have the greatest uncertainty, in part because of more complex effects. ________ --"The signature or fingerprint of anthropogenic greenhouse-gas forcing, as predicted by the models on which the IPCC relies, is distinct from that of any other forcing, in that the models project that the rate of change in temperature in the tropical mid-troposphere – the region some 6-10 km above the surface – will be twice or thrice the rate of change at the surface (Figure 4):" That's a general tendency with any global warming - it isn't as apparent in the graph for the response to solar forcing because the solar forcing used is so small in comparison. The fingerprint of increased greenhouse gases is cooling of the upper atmosphere, which has occured, and is not expected from a positive solar forcing. Granted that the response to ozone changes is more similar to greenhouse gas forcing (though there are differences), but it wouldn't make sense to arbitrarily suppose we can't tell at all how much is from what, especially given knowlege of radiative forcing. --"However, as Douglass et al. (2004) and Douglass et al. (2007) have demonstrated, the projected fingerprint of anthropogenic greenhouse-gas warming in the tropical mid-troposphere is not observed in reality. Figure 6 is a plot of observed tropospheric rates of temperature change from the Hadley Center for Forecasting. In the tropical mid-troposphere, at approximately 300 hPa pressure, the model-projected fingerprint of anthropogenic greenhouse warming is absent from this and all other observed records of temperature changes in the satellite and radiosonde eras:" The radiosonde record may have a bias due to the nature of the devices used. There has been some disagreement but I think the satellite record turned out to reveal tropospheric warming and stratospheric cooling, as expected, though off hand I don't know about the distribution within the troposphere. The graph shown appears to indicate tropospheric warming and stratospheric cooling, which seems to support the idea of greenhouse-forcing induced warming. --"There are two principal reasons why the models appear to be misrepresenting the tropical atmosphere so starkly. First, the concentration of water vapor in the tropical lower troposphere is already so great that there is little scope for additional greenhouse-gas forcing." Interesting, but increasing water vapor higher in the troposphere would still have important effects. --"Secondly, though the models assume that the concentration of water vapor will increase in the tropical mid-troposphere as the space occupied by the atmosphere warms, advection transports much of the additional water vapor poleward from the tropics at that altitude." That likely only would happen if the water vapor amount increases in the tropics at that altitude. Increased water vapor in the tropics and increased advection of water vapor don't contradict the other - they should tend to go together. --"Since the great majority of the incoming solar radiation incident upon the Earth strikes the tropics, any reduction in tropical radiative forcing has a disproportionate effect on mean global forcings." Only in the wavelengths dominated by solar radiation (SW radiation; the greenhouse effect deals with LW radiation - it too can vary with latitude, but ...). --"On the basis of Lindzen (2007), the anthropogenic-ear radiative forcing as established in Eqn. (3) are divided by 3 to take account of the observed failure of the tropical mid-troposphere to warm as projected by the models –" This is nonsense. The radiative forcing being considered is clearly the external forcing. What is being asserted here is that the feedbacks are not the same as expected - distinctly different, even if it were correct. None of this discussion justifies dividing external radiative forcing by 3 or any number. ----------- PS Lindzen himself, though not free of mistakes in general, did not make this same mistake in the work Monckton is citing. See DELTOID: "Monckton's triple counting" I didn't go into a lot of Monckton's statements over k (seems like a waste of time considering...) but see the DELTOID work just mentioned, which states: --"What Monckton is doing is double counting his (dubious) evidence that sensitivity is lower than the IPCC number. If he had two pieces of evidence that sensitivity is half the IPCC number he would multiply them together to claim that sensitivity is one quarter the IPCC number. This is not correct." PS this DELTOID writing is far more brief than what I wrote here. ----------- --"it is simple to calculate that, in 2001, one of the IPCC’s values for f was 2.08. Thus the value f = 3.077 in IPCC (2007) represents a near-50% increase in the value of f in only five years." He's comparing one value to what? An average? That's an odd way to assert a 50 % increase. --"With these assumptions, ? is shown to be less, and perhaps considerably less, than the value implicit in IPCC (2007). The method of finding ? shown in Eqn. (24), which yields a value very close to that of IPCC (2007), is such that progressively smaller forcing increments would deliver progressively larger temperature increases at all levels of the atmosphere, contrary to the laws of thermodynamics and to the Stefan-Boltzmann radiative-transfer equation (Eqn. 18), which mandate the opposite." Well, that's odd, since IPCC temperature projections increase with increasing radiative forcing. I didn't bother to check whether Monckton's application of Stefan-Boltzman was correct or not. --"the feedback-sum b cannot exceed 3.2 W m–2 K–1 without inducing a runaway greenhouse effect. " I think he's misunderstanding something here. I suspect the IPCC listing of feedbacks are in total after taking into account their responses to each other. --"Figure 7" "Fluctuating CO2 but stable temperature for 600m years" The sun increases in brightness over hundreds of millions of years, so the same CO2 level 500 million years ago would allow a cooling relative to now. CO2 forcing is roughly logarithmic to changes in concentration within a certain range; An increase from 280 ppm to 7000 ppm is 4.64 doublings. 7000 ppm is one of the higher estimates of CO2 for that time period. Not shown is a possible dip in CO2 in the late Ordivician. The temperature graph is unrealistic and cartoonish (which may be fine for some purposes, but not here) and no one can say that global average surface temperature has not exceeded 22 deg C during the time span shown. --"The Bode equation, furthermore, is of questionable utility because it was not designed to model feedbacks in non-linear objects such as the climate." Yes, that's what the climate models are for. --"since CO2 occupies only one-ten-thousandth part more of the atmosphere that it did in 1750" That's over 30% relative to CO2 concentration in 1750. Which is enough for CO2. ________________________________________________________ The other (opposing) paper "A Tutorial on the Basic Physics of Climate Change": A decent brief overview for introductory purposes, although they leave themselves open to not taking into account convection and variations in optical properties over wavelength. But the IPCC, etc. findings certainly do take into account these things. For more, see my attempt to explain it qualitatively but clearly at "Tropical Storm Bertha" I mention there a particularly useful book (draft copy available online) by Ray Pierrehumbert: "Principles of Planetary Climate". _____________________________________________ CLARIFICATION/CORRECTION: --"Since the great majority of the incoming solar radiation incident upon the Earth strikes the tropics, any reduction in tropical radiative forcing has a disproportionate effect on mean global forcings." I wrote: "Only in the wavelengths dominated by solar radiation (SW radiation; the greenhouse effect deals with LW radiation - it too can vary with latitude, but ...). " Actually, I should have just said No. Because radiative forcing is what it is; that it might be a smaller percentage of the radiative fluxes in the tropics if it itself doesn't vary in latitude much is irrelevent for finding the global average. Actually, invariance over latitude invariance isn't the case - direct forcing by increases of CO2 and some other greenhouse gases is greatest in the subtropics and least in polar regions; the near surface climate response is opposite that pattern because of the distribution of feedbacks - albedo feedbacks of less winter snow (at latitudes that get winter sun) and summer polar sea-ice loss (open water stores solar heat and releases it in the dark polar winter, delaying ice formation), and greater evaporative cooling of tropical waters which reduces surface warming but contributes (upon condensation) to the warming of the middle-to-upper troposphere. ----------------------- 3.models can not reproduce every aspect of the weather and climate system exactly - this does not mean they are not very useful. The apparent reduced warming of the mid to upper low-latitude troposphere would be just as puzzling if the cause of warming were solar brightenning.
130939. chris at 10:55 AM on 10 October 2008
        Can animals and plants adapt to global warming?
        Re #49: It's encouraging that you consider that we should address the acidification of the oceans. However fertilizer runoff makes a trivial contribution to ocean acidification, although it does have seriously degrading effects on streams and rivers, and can cause largescale esturial deadzones as a result of promotion of seasonal algal blooms followed by de-oxygenation (e.g. see seasonal de-oxygenation around Chesapeake Bay and the Mississippi delta in the Gulf of Mexico). What is causing the accelerating acidification of the worlds oceans? It's our CO2 emissions Quietman. Around 40-50% of our CO2 emissions are absorbed by the oceans, and this humungous amount is causing the oceans to acidify [CO2 + H2O <-----> H2CO3 <------> HCO3- + H+ <----> CO32- + H+; remember that H+ is acid] Try: Feely, RA et al (2004) "Impact of anthropogenic CO2 on the CaCO3 system in the oceans" Science 305, 362-366. Abstract: "Rising atmospheric carbon dioxide (CO2) concentrations over the past two centuries have led to greater CO2 uptake by the oceans. This acidification process has changed the saturation state of the oceans with respect to calcium carbonate (CaCO3) particles. Here we estimate the in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data, and we also discuss the future impacts of anthropogenic CO2 on CaCO3 shell forming species. CaCO3 dissolution rates, ranging from 0.003 to 1.2 micromoles per kilogram per year, are observed beginning near the aragonite saturation horizon. The total water column CaCO3 dissolution rate for the global oceans is approximately 0.5 +/- 0.2 petagrams of CaCO3-C per year, which is approximately 45 to 65% of the export production of CaCO3." Sabine, CL et al. (2004) "The oceanic sink for anthropogenic CO2" Science 305, 367-371. "Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for similar to48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential." The effects of this acidification on oceanic life is reviewed recently here and is rather relevant to the subject of this thread: Hoegh-Guldberg O et al. (2007) "Coral reefs under rapid climate change and ocean acidification" Science 318, 1737-1742. Abstract: "Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2 degrees C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Under conditions expected in the 21st century, global warming and ocean acidification will compromise carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse reef communities and carbonate reef structures that fail to be maintained. Climate change also exacerbates local stresses from declining water quality and overexploitation of key species, driving reefs increasingly toward the tipping point for functional collapse. This review presents future scenarios for coral reefs that predict increasingly serious consequences for reef- associated fisheries, tourism, coastal protection, and people. As the International Year of the Reef 2008 begins, scaled- up management intervention and decisive action on global emissions are required if the loss of coral- dominated ecosystems is to be avoided. " The oceans will gradually lose their ability to absorb large fractions of our emissions and atmospheric greenhouse gas levels will be enhanced as a result. Already there is evidence that this effect is beginning to be apparent: Le Quere C et al (2007) "Saturation of the Southern Ocean CO2 sink due to recent climate change" 316, 1735-1738. Abstract: "Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale."
130940. chris at 10:20 AM on 10 October 2008
        Can animals and plants adapt to global warming?
        Re # 48 [chris said: "We know things are going to become increasingly problematic in a warming world"] [Quietman replied: "Not! Again assumption based on a hypothesis. Just because a belief is accepted does not make it true, it's like saying God did it."] No. It's not an "assumption based on a hypothesis"...it's a conclusion based on the evidence. If we don't address the evidence we're in trouble. We can't address future consequences by ignoring the evidence and putting our money on things that we know not to be true.
130941. chris at 09:50 AM on 10 October 2008
        Water vapor is the most powerful greenhouse gas
        #4 and #6 Mizimi - please think before posting: #4: Water vapour amplifies whatever source of warming caused the atmosphere to warm,since atmospheric warming results in raised atmospheric water concentrations. And water vapour is a greenhouse gas as we all know very well. If the earth's atmosphere cools so the water vapour drops AMPLIFYING the primary cooling effect. Amplification is exactly what water vapour does with respect to thermal effects on atmospheric temperature. It's exactly the right term to use. There's nothing "emotively biased" about it! ------------------------------- Greenhouse gases apply a thermal FORCING. Forcing is an appropriate word to use since greenhouse gases do not instantaneously warm the atmosphere (and indirectly the surface). The apply a constant forcing that results in a shift in the atmospheric (and indirectly the surface) temperature towards a higher equilibrium value. There's nothing "emotively biased" about using appropriate terms. Sadly we can't "magic away" reality by semantic quibbling! --------------------------------- #6: Re feedbacks. Water vapour is the dominant greenhouse gas in the earth's atmnosphere. Together with CO2, water vapour supplements the earth's black body temperature (around minus 15 oC) with around 30 oC of enhanced warmth. This has been known and understood since the middle of the 19th century. How you can pretend that water vapour cools the atmosphere is a mystery. If only we could magic away problematic reality by asserting that things are exactly opposite to what they are in reality! It's easy to highlight your dull fallacy. You state -Mizimi: "Water vapour is present in the upper troposphere; thus it radiates heat outwards and has a cooling effect". Let's pretend first that the water vapour wasn't there: the infra-red radiation emitted from the earth's surface just passes freely into space. Now add back the water vapour. The water vapour absorbs the IR radiation emitted from the earth's surface AND RADIATES IT IN ALL DIRECTIONS EQUALLY (as well as passing kinetic energy to other gas molecules in its surrounds). In other words it suppresses the ability of infra-red radiation emitted from the earth to pass unhindered to space. In other, other, words it warms the atmosphere. Let's not make up stuff to pursue the pretence that we don't know what we do know!
130942. chris at 06:58 AM on 10 October 2008
        Can animals and plants adapt to global warming?
        Re #47 Quietman, you've rather changed the subject in your response. My response in post #44 was to your comment in #41. But we're getting used to that... Let's switch to your new slant..that extinction drives evolution. Fine, that's a supportable statement. Stephen Jay Gould's "Wonderful Life" is a decent example. It shows that evolution potentially leads to the flourishing of novel life forms within the "empty" niches that result from major extinctions, as characterised by the Cambrian expansion of forms identified within the Burgess Shale. But you are resorting again to your dissociated non-humanism: "Wouldn't it be interesting if we had another major extinction....in several hundred thousand or a few million years afterwards what a fascinating diversity of life forms might arise..." If you want to go there, that's fine. But the rest of us would prefer not to pursue a relentless drive towards the next major extinction. That's not a future that the overwhelming majority of humanity wishes to pursue, however interesting you might consider it. The fact is that the evidence indicates rather strongly that rapid global scale warming are associated with major extinctions in the earth's history. We can pretend that the greenhouse effect doesn't exist and pursue "interesting" catastrophic scenarios. In real life I suspect that we're going to be rather more mature and rational, and direct our focus onto the coming decades and few centuries (rather than an "interesting" post-extinction potential diversification some millions of years in the future). Re the greenhouse effect: I'm afraid the greenhouse effect is a fact Quietman. Our (sciences's) understanding of the world is not defined by one individuals ignorance. Re "assumptions" and the "IPCC" You've got that wrong again. You've said something in your post #43 that simply isn't true. If one has to contrive untruths and then pursue these to attempt to make a point, then the point is really not worth making, is it. To reiterate, the work described in the papers/reviews I cited in my post #35 make no assumptions whatsoever about the supposed "climate sensitivity" or any supposed "hypotheses" of the IPCC. Untruths do not equate to "skepticism".
130943. DB2 at 05:45 AM on 10 October 2008
        Is Antarctic ice melting or growing?
        Forests play an important role in carbon sequestration. This research finds that net primary productivity in temperate forests would increase 25% with a carbon dioxide concentration of 550 ppm. Boreal forests would see an increase of 15% while tropical forest would increse NPP by 35%. CO2 fertilization in temperate FACE experiments not representative of boreal and tropical forests Thomas Hickler et al. Global Change Biology (2008) 14, 1531–1542 http://face.env.duke.edu/PDF/gcb14-08c.pdf Abstract: Results from free-air CO2 enrichment (FACE) experiments in temperate climates indicate that the response of forest net primary productivity (NPP) to elevated CO2 might be highly conserved across a broad range of productivities. In this study, we show that the LPJ-GUESS dynamic vegetation model reproduces the magnitude of the NPP enhancement at temperate forest FACE experiments. A global application of the model suggests that the response found in the experiments might also be representative of the average response of forests globally. However, the predicted NPP enhancement in tropical forests is more than twice as high as in boreal forests, suggesting that currently available FACE results are not applicable to these ecosystems. The modeled geographic pattern is to a large extent driven by the temperature dependence of the relative affinities of the primary assimilation enzyme (Rubisco) for CO2 and O2.
130944. DB2 at 05:42 AM on 10 October 2008
        Is Antarctic ice melting or growing?
        It is important to differential between precipitation and soil moisture. It is moisture in the soil that (land) plants can actually use. Climate models predict that a warmer world means drier soil, a result of more evaporation, with a resultant threat to our food supply. Two papers by Robock et al. look at historical soil moisture data to see if the real world has followed the models. Both paper can be found here by clicking on 'Recent Publications'. http://climate.envsci.rutgers.edu/soil_moisture/ The Global Soil Moisture Data Bank Bull. Amer. Meteorol. Soc. (2000) 81, 1281-1299 Forty five years of observed soil moisture in the Ukraine: No summer desiccation (yet) Geophys. Res. Lett. (2005) 32, L03401 The 2000 paper looked at data from the former Soviet Union, China, Mongolia, India and the US compared to GCM predictions. They found that "although this model predicts summer desiccation in the next century, it does not in general reproduce the observed upward trends in soil moisture very well." The trends of the data and model were in opposite directions. "In contrast to predictions of summer desiccation with increasing temperatures, for the stations with the longest records, summer soil moisture in the top 1 m has increased while temperatures have risen." In the 2005 paper they look at "the longest data set of observed soil moisture available in the world, 45 years of gravimetrically-observed plant available soil moisture for the top 1 m of soil, observed every 10 days for April-October for 141 stations from fields with either winter or spring cereals from the Ukraine for 1958-2002." They find that "the observations show a positive soil moisture trend for the entire period of observation, with the trend leveling off in the last two decades," noting that "even though for the entire period there is a small upward trend in temperature and a downward trend in summer precipitation, the soil moisture still has an upward trend for both winter and summer cereals." "Although models of global warming predict summer desiccation in a greenhouse-warmed world, there is no evidence for this in the observations yet, even though the region has been warming for the entire period."
130945. Quietman at 04:52 AM on 10 October 2008
        Climate sensitivity is low
        Patrick Science and Society is a good blog but Disney owns ABC and therefore the site and does not allow links. That is why an argument on AGW is better done here. John allows links and actually prefers hyperlinks. But he has asked us to keep the discussion pertinent to the thread and not post "lists of links" so I try to break up my comments for readability. PS I looked at your remark on THERMODYNAMICS but skipped most of the other links purely because I don't care to go to that web site. Articles and Papers are much more appreciated as links (less opinion and more facts).
130946. chris at 04:49 AM on 10 October 2008
        Climate's changed before
        interesting questions; some are easily answered, some less so: [Has any research been done on just how much water vapour can be held in the atmosphere and the warmer temperatures before it reaches saturation point?] It depends where you are in the atmosphere since the saturation level varies with temperature and pressure. These data are known quite acurately 'though. You can see the variation of saturation of air with water vapour as a function of temperature here (scroll down the page to find the relevant graph): http://en.wikipedia.org/wiki/Water_vapor [And also explain to me why Douglas Hoyt's info is so dodgy. He's fairly knowledgeable in the field so why is his contribution so wrong? How do we know what's right or wrong?] One can compare Hoyt's assertions with reality. They don't match. Therefore in this instance we know Hoyt is wrong. A problem is that Hoyt hasn't published anything on this. he's just asserting stuff on a web site. Since he may well have written it in 2004, perhaps he thought it was correct then but doesn't realize that real world data now contradicts his assertion; perhaps he just hasn't bothered to update his web site. We'd have to ask him... Hoyt has made the assertion (on his website) that gravity effects will eliminate 90% of the warming-induced enhancement of water vapour concentrations. The Minschwaner and Dessler paper that Hoyt refers to indicates a possibility of a much smaller reduction in enhanced water vapour. So even in 2004, Hoyt's assertion didn't match reality. Now we have much better measures of atmospheric water vapour, and it's clear that the atmospheric water vapour concentrations rise pretty much as predicted by theory and modelling. As well as the articles whose abstracts are listed in my post above, more recent analyses (see [**] below) of direct tropospheric water vapour demonstrate that the water vapour concentrations are rising in response to warming pretty much as predicted. So Hoyt is demonstrably wrong. [You can justify comments with 'scientific proof' but how do we know that it is correct?] It's not really about "proof". It's about the evidence. In this case Hoyt is making assertions that are directly contradicted by the evidence. So in this instance Hoyt is demonstrably wrong. A lot of the efforts in dealing with so-called "skeptical" (!) "arguments" is in pointing out their inherent self-contradictions. Hoyt is also wrong (it seems to me) on straightforward theoretical/empirical grounds that relate to the competing effects of gravity and thermal kinetic energy on isolated molecules in a vapour as I outlined in my post just above. [are you prepared to take someone's word for it?] Yes and no. If someone has a habit of dishonesty of course one would be foolish to take their word. Likewise if someone is respected for their honesty and diligence, I'm more likely to take them at face value. I am always skeptical of stuff that is asserted on this or that web site, and if one investigates further and finds that the asserter hasn't published the relevant work (or in this case hasn't published anything for 10 years), makes assertions that are not supported by any evidence, and upon further investigation, finds that the assertions are actually directly contradicted by real world evidence, then it would be foolish not to discount the assertions. One should be skeptical about these things! [Is there some corruption not only from the climate change skeptics but also from the IPCC and other anthropogenic climate change supporters?] Corruption is usually identifiable. Can you identify any IPCC "corruption"? I haven't come across any. That doesn't mean the IPCC are paragons of perfection! If anything the IPCC presentations are somewhat conservative. [It's all very interesting but doesn't everyone within this current issue have an agenda?] I wouldn't have said so. There's clearly a strong agenda position to misrepresent the science amongst certain quarters (you see quite a lot of it from a cohort of posters on this web site). In my experience the only "agenda" the scientists have is to get to the bottom of whatever topic their researching, preferably making some good discoveries along the way and publishing some well-respected and highly-cited papers. [***] Gettelman A and Fu Q (2008) “Observed and simulated upper-tropospheric water vapor feedback” J. Climate 21, 3282-3289. Abstract: “Satellite measurements from the Atmospheric Infrared Sounder (AIRS) in the upper troposphere over 4.5 yr are used to assess the covariation of upper-tropospheric humidity and temperature with surface temperatures, which can be used to constrain the upper-tropospheric moistening due to the water vapor feedback. Results are compared to simulations from a general circulation model, the NCAR Community Atmosphere Model (CAM), to see if the model can reproduce the variations. Results indicate that the upper troposphere maintains nearly constant relative humidity for observed perturbations to ocean surface temperatures over the observed period, with increases in temperature similar to 1.5 times the changes at the surface, and corresponding increases in water vapor ( specific humidity) of 10% -25% degrees C-1. Increases in water vapor are largest at pressures below 400 hPa, but they have a double peak structure. Simulations reproduce these changes quantitatively and qualitatively. Agreement is best when the model is sorted for satellite sampling thresholds. This indicates that the model reproduces the moistening associated with the observed upper-tropospheric water vapor feedback. The results are not qualitatively sensitive to model resolution or model physics.” Brogniez H and Pierrehumbert RT (2007) “Intercomparison of tropical tropospheric humidity in GCMs with AMSU-B water vapor data” Geophys. Res. Lett. 34, Article Number: L17812 Abstract: “We make use of microwave measurements of the tropical free tropospheric relative humidity (FTH) to evaluate the extent to which the water vapor distribution in four general circulation models is faithful to reality. The comparison is performed in the tropics by sorting the FTH in dynamical regimes defined upon the 500 hPa vertical velocity. Because microwave radiation penetrates non-rainy and warm clouds, we are able to estimate the FTH over most of the dynamical regimes that characterize the tropics. The comparisons reveal that two models simulate a free troposphere drier than observed (< 10%), while the others agree with the observations. Despite some differences, the level of agreement is good enough to lend confidence in the representation of atmospheric moistening processes. A climate change scenario, tested on two models, shows a tendency to maintain the FTH to an almost fixed value be it an ascending or a subsiding regime” ',
130947. Quietman at 04:42 AM on 10 October 2008
        Can animals and plants adapt to global warming?
        Re: "So self-preservation also informs us to act rationally to limit our greenhouse gas emissions. " It certainly won't hurt anything to do so but carried to extremes (read CO2) will hurt everybody. Take action on true pollutants. Acidification of the ocean - control fertilizer runoff for starters. Grow more C4 plants (thanks Mizimi) and stop forest destruction by evacuating southern California so they can;t start the damn fires.
130948. Quietman at 04:36 AM on 10 October 2008
        Can animals and plants adapt to global warming?
        Re: "We know things are going to become increasingly problematic in a warming world" Not! Again assumption based on a hypothesis. Just because a belief is accepted does not make it true, it's like saying God did it.
130949. Quietman at 04:34 AM on 10 October 2008
        Can animals and plants adapt to global warming?
        Chris Re: "You've mixed up "evolution" with "extinction"." Extinction drives Evolution by reducing diversity followed by rapid increases in diversity. I suggest Bob Bakker's book "The Dinosaur Heresies" and Steve Gould's "Wonderful Life" as a good place to start. Re: "That's a fact. Let's not pretend that we don't know what we do know." Not factual. It remains hypothetical until proven. It can be demostrated by math but only using assumptions as variables because not all variables have been accurately measured. That is why it was ignored for almost a century. Sooooo That's a fact. Let's not pretend that we don't know what we do know. Re: "They make no assumptions whatsoever" That is what an argument is. Why would anyone write a paper without an assumption (hypothesis). The GHG hypothesis has been discussed amongst paleontologists for about a hundred years now and has been widely accepted for various extinction hypotheses but we realize that it is a hypothesis and accept it as that.
130950. Quietman at 04:03 AM on 10 October 2008
        Is Antarctic ice melting or growing?
        PS I also grow a lot of rocks but as they are sediments with fossils from the upper carboniferous period, I don't mind at all.

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