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New research from last week 2/2012

Posted on 17 January 2012 by Ari Jokimäki

In this week's papers global warming is cancelled. Couple of studies almost make it look like northern hemisphere hasn't warmed at all. Antarctic snowmelt hasn't increased either, and mass loss of Svalbard glaciers is at least slowing down. One study does see a GHG effect but there still might be less warming than usually is projected. On the other hand, only modest warming does some nasty things to tropical insects and arachnids, and even without warming, ocean acidification is going to cost us billions and billions of dollars (I'm glad that Euro is our currency here in Finland).

Looking at other papers this week, I bet you wouldn't like to swim in Paleozoic tropical oceans. Scientists have done fancy tricks with Greenland ice core to reveal secrets of an old volcanic eruption. Lord Kelvin seems to be still doing science. Deforestation appears at least in some sense to be cool. We also have studies on sea level rise of southern Europe coast, North-Atlantic warming, Holocene abrupt climate changes, oceanic freshwater fluxes, and South Asia warming distribution.

Deforestation induces large increases in cold event frequency and intensity in South-America

Simulated links between deforestation and extreme cold events in South America - Medvigy et al. (2012)

Abstract: "Many modeling studies have indicated that deforestation will increase the average annual temperature in the Amazon. However, few studies have investigated the potential for deforestation to change the frequency and intensity of extreme events. This problem is addressed here using a variable-resolution GCM. The characteristic length scale (CLS) of the model’s grid mesh over South America is 25 km, comparable to that used by limited-area models. For computational efficiency, the CLS increases to 200 km over the rest of the world. It is found that deforestation induces large changes in the frequency of wintertime extreme cold events. Large increases in cold event frequency and intensity occur in the western Amazon and, surprisingly, in parts of southern South America, far from the actual deforested area. One possible mechanism for these remote effects involves changes in the position of the subtropical jet, caused by temperature changes in the Amazon. Increased understanding of these potential changes in extreme events will be important for local agriculture, natural ecosystems, and the human population."

Citation: David Medvigy, Robert L. Walko, and Roni Avissar, Journal of Climate 2012, doi:

Oceanic freshwater flux changes tend to amplify rather than suppress the global warming

Can oceanic freshwater flux amplify global warming? - Zhang & Wu (2012)

Abstract: "The roles of freshwater flux (defined as evaporation minus precipitation) changes in global warming are studied using simulations of a climate model in which the freshwater flux changes are suppressed in the presence of a doubling of CO2 concentration. The model simulations demonstrate that the warm climate leads to an acceleration of global water cycle which causes freshening in the high latitudes and salinification in the subtropics and midlatitudes. It is found that the freshwater flux changes tend to amplify rather than suppress the global warming. Over the global scale, this amplification is largely associated with high latitude freshening in a warm climate, which leads to a shoaling of the mixed layer depth, weakening of vertical mixing and thus a trapping of CO2-induced warming in the surface ocean. The latitudinal distribution of SST changes due to the effects of freshwater flux changes in a warm climate is complicated, which involves anomalous advection induced by both salinity and wind stress changes. In addition, atmospheric feedbacks associated with global warming also amplify the SST warming."

Citation: Liping Zhang and Lixin Wu, Journal of Climate 2012, doi:

Many causes of North Atlantic mid 1990's rapid warming

Causes of the Rapid Warming of the North Atlantic ocean in the mid 1990s - Robson et al. (2012)

Abstract: "In the mid-1990s the subpolar gyre of the North Atlantic underwent a remarkable rapid warming, with sea surface temperatures increasing by around 1C in just 2 years. This rapid warming followed a prolonged positive phase of the North Atlantic Oscillation (NAO), but also coincided with an unusually negative NAO index in the winter of 1995/96. By comparing ocean analyses and carefully designed model experiments we show that this rapid warming can be understood as a delayed response to the prolonged positive phase of the NAO, and not simply an instantaneous response to the negative NAO index of 1995/96. Furthermore, we infer that the warming was partly caused by a surge, and subsequent decline, in the Meridional Overturning Circulation and northward heat transport of the Atlantic Ocean. Our results provide persuasive evidence of significant oceanic memory on multi-annual timescales, and are therefore encouraging for the prospects of developing skillful predictions."

Citation: Jon Robson, Rowan Sutton, Katja Lohmann, Doug Smith and Matthew D. Palmer, Journal of Climate 2012, doi:

Using Lord Kelvin's measurements to determine smoke emissions in 1859

Smoke emissions from industrial western Scotland in 1859 inferred from Lord Kelvin’s atmospheric electricity measurements - Aplin (2012)

Abstract: "Lord Kelvin (William Thomson) made careful, calibrated measurements of the atmospheric Potential Gradient (PG) at three sites on the east side of Arran in 1859. The PG was always anomalously high in easterly and north-easterly winds. Positive space charge from sea spray may have contributed to the high PG at two coastal sites, but measurements made on Goatfell, inland and 100-175 m above sea level are unlikely to have been affected by spray. Instead, pollution from the Scottish mainland seems the more likely cause of the high PG at Goatfell, which varied from 300 to 1000 Vm−1 on 10th-11th October 1859, corresponding to smoke levels from 0.2 to 0.8 mgm−3. Gaussian plume calculations, based on the atmospheric conditions described by Lord Kelvin, and constrained by early Glaswegian pollution measurements, indicate a substantial source region located on the Scottish mainland, 20-40 km from Arran, emitting between 10-104 kgs−1."

Citation: K.L. Aplin, Atmospheric Environment,

Tropical ectotherms are heading for catastrophe even with modest predicted warming

Degrees of disruption: projected temperature increase has catastrophic consequences for reproduction in a tropical ectotherm - Zeh et al. (2012)

Abstract: "Although climate change models predict relatively modest increases in temperature in the tropics by the end of the century, recent analyses identify tropical ectotherms as the organisms most at risk from climate warming. Because metabolic rate in ectotherms increases exponentially with temperature, even a small rise in temperature poses a physiological threat to tropical ectotherms inhabiting an already hot environment. If correct, the metabolic theory of climate warming has profound implications for global biodiversity, since tropical insects and arachnids constitute the vast majority of animal species. Predicting how climate change will translate into fitness consequences for tropical arthropods requires an understanding of the effects of temperature increase on the entire life history of the species. Here, in a comprehensive case study of the fitness consequences of the projected temperature increase for the tropics, we conducted a split-brood experiment on the neotropical pseudoscorpion, Cordylochernes scorpioides, in which 792 offspring from 33 females were randomly assigned at birth to control- and high-temperature treatments for rearing through the adult stage. The diurnally-varying, control-treatment temperature was determined from long-term, average daily temperature minima and maxima in the pseudoscorpion's native habitat. In the high-temperature treatment, increasing temperature by the 3.5 °C predicted for the tropics significantly reduced survival and accelerated development at the cost of reduced adult size and a dramatic decrease in level of sexual dimorphism. The most striking effects, however, involved reproductive traits. Reared at high temperature, males produced 45% as many sperm as control males, and females failed to reproduce. Sequencing of the mitochondrial ND2 gene revealed two highly divergent haplogroups that differed substantially in developmental rate and survivorship but not in reproductive response to high temperature. Our findings suggest that reproduction may be the Achilles’ heel of tropical ectotherms, as climate warming subjects them to an increasingly adverse thermal environment."

Citation: Jeanne A. Zeh, Melvin M. Bonilla, Eleanor J. Su, Michael V. Padua, Rachel V. Anderson, Dilpreet Kaur, Dou-Shuan Yang, David W. Zeh, Global Change Biology, DOI: 10.1111/j.1365-2486.2012.02640.x.

Global warming has increased Eurasian snow cover which cools boreal winters

Arctic warming, increasing snow cover and widespread boreal winter cooling - Cohen et al. (2012) [FULL TEXT]

Abstract: "The most up to date consensus from global climate models predicts warming in the Northern Hemisphere (NH) high latitudes to middle latitudes during boreal winter. However, recent trends in observed NH winter surface temperatures diverge from these projections. For the last two decades, large-scale cooling trends have existed instead across large stretches of eastern North America and northern Eurasia. We argue that this unforeseen trend is probably not due to internal variability alone. Instead, evidence suggests that summer and autumn warming trends are concurrent with increases in high-latitude moisture and an increase in Eurasian snow cover, which dynamically induces large-scale wintertime cooling. Understanding this counterintuitive response to radiative warming of the climate system has the potential for improving climate predictions at seasonal and longer timescales."

Citation: Judah L Cohen et al 2012 Environ. Res. Lett. 7 014007 doi:10.1088/1748-9326/7/1/014007.

Increased cloud cover has slowed summer warming in Eurasia

Damped summer warming accompanied with cloud cover increase over Eurasia from 1982 to 2009 - Tang & Leng (2012) [FULL TEXT]

Abstract: "The relationship between summer temperature, total cloud cover and precipitation over Eurasia was investigated using observation-based products of temperature and precipitation, and satellite-derived cloud cover and radiation products. We used a partial least squares regression approach to separate the local influences of cloud cover and precipitation on temperature variations. Our results suggest that the variance of summer temperature is partly explained by changes in summer cloudiness. The summer temperature dependence on cloud cover is strong at the high latitudes and in the middle latitude semi-humid area, while the dependence on precipitation is strong in the Central Asia arid area and the southern Asia humid area. During the period 1982–2009, the damped warming in extended West Siberia was accompanied with increases in cloud cover, and the pronounced warming in Europe and Mongolia was associated with a decrease in cloud cover and precipitation. Our results suggest that cloud cover may be the important local factor influencing the summer temperature variation in Eurasia while precipitation plays an important role at the middle latitudes."

Citation: Qiuhong Tang and Guoyong Leng 2012 Environ. Res. Lett. 7 014004 doi:10.1088/1748-9326/7/1/014004.

Study finds no statistically significant changes in Antarctic snowmelt since 1979

Insignificant change in Antarctic snowmelt volume since 1979 - Munneke et al. (2012) [FULL TEXT]

Abstract: "Surface snowmelt is widespread in coastal Antarctica. Satellite-based microwave sensors have been observing melt area and duration for over three decades. However, these observations do not reveal the total volume of meltwater produced on the ice sheet. Here we present an Antarctic melt volume climatology for the period 1979–2010, obtained using a regional climate model equipped with realistic snow physics. We find that mean continent-wide meltwater volume (1979–2010) amounts to 89 Gt y−1 with large interannual variability (σ = 41 Gt y−1). Of this amount, 57 Gt y−1 (64%) is produced on the floating ice shelves extending from the grounded ice sheet, and 71 Gt y−1 in West-Antarctica, including the Antarctic Peninsula. We find no statistically significant trend in either continent-wide or regional meltwater volume for the 31-year period 1979–2010."

Citation: Kuipers Munneke, P., G. Picard, M. R. van den Broeke, J. T. M. Lenaerts, and E. van Meijgaard (2012), Insignificant change in Antarctic snowmelt volume since 1979, Geophys. Res. Lett., 39, L01501, doi:10.1029/2011GL050207.

Production loss of mollusks due to ocean acidification could be over 100 billion USD

Economic costs of ocean acidification: a look into the impacts on global shellfish production - Narita et al. (2012)

Abstract: "Ocean acidification is increasingly recognized as a major global problem. Yet economic assessments of its effects are currently almost absent. Unlike most other marine organisms, mollusks, which have significant commercial value worldwide, have relatively solid scientific evidence of biological impact of acidification and allow us to make such an economic evaluation. By performing a partial-equilibrium analysis, we estimate global and regional economic costs of production loss of mollusks due to ocean acidification. Our results show that the costs for the world as a whole could be over 100 billion USD with an assumption of increasing demand of mollusks with expected income growths combined with a business-as-usual emission trend towards the year 2100. The major determinants of cost levels are the impacts on the Chinese production, which is dominant in the world, and the expected demand increase of mollusks in today’s developing countries, which include China, in accordance with their future income rise. Our results have direct implications for climate policy. Because the ocean acidifies faster than the atmosphere warms, the acidification effects on mollusks would raise the social cost of carbon more strongly than the estimated damage adds to the damage costs of climate change."

Citation: Daiju Narita, Katrin Rehdanz and Richard S. J. Tol, Climatic Change, DOI: 10.1007/s10584-011-0383-3.

Analysis of abrupt climate changes during Holocene

Patterns, processes, and impacts of abrupt climate change in a warm world: the past 11,700 years - Shuman (2012)

Abstract: "Abrupt environmental changes punctuated the warm Holocene epoch (the past ∼11,700 years), and studies of these episodes can provide insight into the dynamics that produce rapid climate changes, as well as their ecologic, hydrologic, and geomorphic impacts. This review considers the processes that generated warm world abrupt changes and their landscape and resource effects, including nonlinear climate system interactions, as well as the possibility that large climate variability can linearly produce apparent ‘state shifts.’ Representative examples of Holocene changes illustrate processes that could produce future changes, including (1) rapid changes in ice sheets, such as by ca 8200 years before AD 1950, (2) shifts in the behavior of the El Nino-Southern Oscillation (e.g., at ca 5600 years before AD 1950) and Atlantic Meridional Overturning Circulation (e.g., at ca 2700 years before AD 1950), and (3) land–atmosphere feedbacks, such as were possible in North Africa in the mid-Holocene. These case examples, drawn primarily from the Northern Hemisphere, also reveal the dynamics that generate the types of climate change impacts that would be particularly evident to individuals and societies, such as rapid tree species declines (observed to have taken place within as little time as 6–40 years) and persistent shifts in the regional availability of water. Holocene changes also demonstrate that even progressive climate change can produce important abrupt impacts; that increased rates of background climate forcing may increase the frequency of abrupt responses; and that impacts may well depend upon the particular sequence of changes."

Citation: Bryan Shuman, Wiley Interdisciplinary Reviews: Climate Change, DOI: 10.1002/wcc.152.

Tropical oceans were colder sometimes during Paleozoic than during last glacial maximum

Low-latitude Ordovician to Triassic brachiopod habitat temperatures (BHTs) determined from δ18O[brachiopod calcite] : A cold hard look at ice-house tropical oceans - Giles (2012)

Abstract: "Some researchers have suggested that Phanerozoic land-based ice sheets extended occasionally into the tropical realm. If true, the tropical ocean at those times must have been distinctly colder than at the Last Glacial Maximum (LGM) when northern hemisphere ice sheets did not extend below 38° latitude. Low-latitude ocean temperatures derived from oxygen isotopes of brachiopod shells test this hypothesis by comparing the temperature regime for Paleozoic and early Mesozoic low-latitude settings to the tropical temperature regime of the modern interstadial ocean, and to mean temperatures estimated for the tropical ocean at LGM. A running mean of pH-adjusted brachiopod habitat temperatures (BHTs) shows that Paleozoic low-latitude oceans were, on average, cool to cold relative to the modern interstadial tropical ocean. At times during Pennsylvanian, Serpukhovian, Tournaisian and Ordovician-Silurian glaciations, these tropical seas were indeed significantly colder on average than at the LGM. Ice-sheets within tropical latitudes can be reasonably predicted at those times. Abundant and diverse Paleozoic brachiopod communities reflect these cool tropical oceans, consistent with modern brachiopod ecological preference for colder waters. Amplified Paleozoic temperature oscillations suggest recurring global warming events which episodically drove these cold tropical oceans to temperatures significantly higher than the warmest modern tropical ocean."

Citation: Peter S. Giles, Palaeogeography, Palaeoclimatology, Palaeoecology,

Ice free Arctic Ocean causes more precipitation which slows down glacier mass loss in Svalbard

The impact of a seasonally ice free Arctic Ocean on the temperature, precipitation and surface mass balance of Svalbard - Day et al. (2012) [FULL TEXT]

Abstract: "The observed decline in summer sea ice extent since the 1970s is predicted to continue until the Arctic Ocean is seasonally ice free during the 21st Century. This will lead to a much perturbed Arctic climate with large changes in ocean surface energy flux. Svalbard, located on the present day sea ice edge, contains many low lying ice caps and glaciers and is expected to experience rapid warming over the 21st Century. The total sea level rise if all the land ice on Svalbard were to melt completely is 0.02 m. The purpose of this study is to quantify the impact of climate change on Svalbard's surface mass balance (SMB) and to determine, in particular, what proportion of the projected changes in precipitation and SMB are a result of changes to the Arctic sea ice cover. To investigate this a regional climate model was forced with monthly mean climatologies of sea surface temperature (SST) and sea ice concentration for the periods 1961–1990 and 2061–2090 under two emission scenarios. In a novel forcing experiment, 20th Century SSTs and 21st Century sea ice were used to force one simulation to investigate the role of sea ice forcing. This experiment results in a 3.5 m water equivalent increase in Svalbard's SMB compared to the present day. This is because over 50 % of the projected increase in winter precipitation over Svalbard under the A1B emissions scenario is due to an increase in lower atmosphere moisture content associated with evaporation from the ice free ocean. These results indicate that increases in precipitation due to sea ice decline may act to moderate mass loss from Svalbard's glaciers due to future Arctic warming."

Citation: Day, J. J., Bamber, J. L., Valdes, P. J., and Kohler, J.: The impact of a seasonally ice free Arctic Ocean on the temperature, precipitation and surface mass balance of Svalbard, The Cryosphere, 6, 35-50, doi:10.5194/tc-6-35-2012, 2012.

South Asia extreme temperature indices show general warming only in low altitudes and latitudes

Impact of altitude and latitude on changes in temperature extremes over South Asia during 1971–2000 - Revadekar et al. (2012)

Abstract: "South Asia covers more than 30° of latitude with weather observation stations situated from 6°N at Galle, Sri Lanka, to 36°N at Chitral in Pakistan. Moreover, the South Asian station network ranges in altitude from sea level to nearly 4000 m above sea level. This paper uses time series of 11 objectively defined indices of daily temperature extremes at 197 stations in Bangladesh, India, Nepal, Pakistan and Sri Lanka to examine the possible impacts of elevation and latitude on changes in temperature extremes over the period of 1971–2000. Trends in extreme indices are consistent with general warming only at low altitudes and latitudes. Stations at high altitudes and latitudes show both positive and negative trends in extreme temperature indices. As a notable example, the Diurnal Temperature Range (DTR), which has been known to decrease in most parts of the globe, has increasing trends over many high altitude stations in South Asia. Trends in extreme temperature indices at stations in South Asia higher than 2000 m above sea level are mostly in disagreement with those reported over the Tibetan Plateau. Observed trends at low altitude locations in South Asia suggest that these sites can generally expect future changes in temperature extremes that are consistent with broad-scale warming. High-elevation sites appear to be more influenced by local factors and, hence, future changes in temperature extremes may be less predictable for these locations."

Citation: J. V. Revadekar, S. Hameed, D. Collins, M. Manton, M. Sheikh, H. P. Borgaonkar, D. R. Kothawale, M. Adnan, A. U. Ahmed, J. Ashraf, S. Baidya, N. Islam, D. Jayasinghearachchi, N. Manzoor, K. H. M. S. Premalal, M. L. Shreshta, International Journal of Climatology, DOI: 10.1002/joc.3418.

Greenland ice core shows that 1783 Laki volcanic plume did not reach stratosphere

Sulfur isotope evidence of little or no stratospheric impact by the 1783 Laki volcanic eruption - Lanciki et al. (2012)

Abstract: "Historic records and research have suggested that the 1783–1784 eruption of the Laki fissure volcano in Iceland impacted Northern Hemisphere climate significantly, probably as a result of the direct injection of volcanic materials into the stratosphere where the volcanic aerosols would linger for years to cause surface cooling across the Northern Hemisphere. However, recent modeling work indicates the Laki climatic impact was limited to the Northern Hemisphere and only in the second half of 1783. We measured sulfur-33 isotope excess (Δ33S) in volcanic sulfate of historical eruptions including Laki found in Summit, Greenland ice cores. No Δ33S excess is found in sulfate of apparently tropospheric eruptions, while sulfate of stratospheric eruptions is characterized by significant Δ33S excess and a positive-to-negative change in Δ33S during its gradual removal from the atmosphere. Because the same characteristics have been previously found in volcanic sulfate in Antarctica snow, the results from Greenland indicate similar global processes of stratospheric chemical conversion of SO2 to sulfate. The isotopic composition of Laki sulfate is essentially normal and shows no characteristics of sulfate produced by stratospheric photochemical reactions. This clearly indicates that the Laki plume did not reach altitudes of the stratospheric ozone layer. Further, the short aerosol residence time (<6 months) suggests that the bulk of the Laki plume and subsequent aerosols were probably confined to the middle and upper troposphere. These conclusions support the hypothesis of D'Arrigo and colleagues that the unusually cold winter of 1783–1784 was not caused by Laki."

Citation: Lanciki, A., J. Cole-Dai, M. H. Thiemens, and J. Savarino (2012), Sulfur isotope evidence of little or no stratospheric impact by the 1783 Laki volcanic eruption, Geophys. Res. Lett., 39, L01806, doi:10.1029/2011GL050075.

Improved constraints lead to relatively low projections of 21st century warming

Improved constraints on 21st-century warming derived using 160 years of temperature observations - Gillett et al. (2012)

Abstract: "Projections of 21st century warming may be derived by using regression-based methods to scale a model's projected warming up or down according to whether it under- or over-predicts the response to anthropogenic forcings over the historical period. Here we apply such a method using near surface air temperature observations over the 1851–2010 period, historical simulations of the response to changing greenhouse gases, aerosols and natural forcings, and simulations of future climate change under the Representative Concentration Pathways from the second generation Canadian Earth System Model (CanESM2). Consistent with previous studies, we detect the influence of greenhouse gases, aerosols and natural forcings in the observed temperature record. Our estimate of greenhouse-gas-attributable warming is lower than that derived using only 1900–1999 observations. Our analysis also leads to a relatively low and tightly-constrained estimate of Transient Climate Response of 1.3–1.8°C, and relatively low projections of 21st-century warming under the Representative Concentration Pathways. Repeating our attribution analysis with a second model (CNRM-CM5) gives consistent results, albeit with somewhat larger uncertainties."

Citation: Gillett, N. P., V. K. Arora, G. M. Flato, J. F. Scinocca, and K. von Salzen (2012), Improved constraints on 21st-century warming derived using 160 years of temperature observations, Geophys. Res. Lett., 39, L01704, doi:10.1029/2011GL050226.

Sea level rise and vertical land motion in southern Europe coast

Coastal sea level rise in southern Europe and the nonclimate contribution of vertical land motion - Wöppelmann & Marcos (2012)

Abstract: "In this study, we extend the advanced approach of combining tide gauge and satellite altimetry data with supplemental equations from adjacent tide gauge records of at least 30 years of common data to investigate the relative importance of the nonclimate contribution of vertical land movement to the observed rates of sea level change along the coasts of southern Europe. The sensitivity tests proved that the advanced approach is robust and accurate at the submillimeter per year level of around 0.4 mm yr−1 in estimating rates of vertical land movements. It enabled identifying stations displaying large rates of vertical land movements that must be taken into account when predicting future sea level rise and appraising the exposure to its impacts on populations and assets. The average rate of coastal climate-related sea level rise in the Mediterranean Sea was consequently revisited to be of 1.7 mm yr−1 over the past century, whereas the Atlantic northern Iberian coast revealed a significant high rate of sea level rise in excess of 3.4 mm yr−1 for the past 70 years. Future work should consider applying this powerful approach to other geographic contexts as a useful source of supplementary data for geodynamic studies."

Citation: Wöppelmann, G., and M. Marcos (2012), Coastal sea level rise in southern Europe and the nonclimate contribution of vertical land motion, J. Geophys. Res., 117, C01007, doi:10.1029/2011JC007469.

CLASSIC OF THE WEEK: Langley (1876)

Measurement of the Direct Effect of Sun-spots on Terrestrial Climates - Langley (1876) [FULL TEXT]

No abstract. In this paper, Samuel Langley (who made the measurements Arrhenius used in his legendary paper) calculates that the effect of sun-spots to the temperature of Earth is between 0.063 and 0.29 degrees Celsius.

Citation: Langley, S. P., 1876, Monthly Notices of the Royal Astronomical Society, Vol. 37, p.5.

?This is a cross-post from AGW Observer. When each paper is published, it is notified in AGW Observer Facebook page and Twitter page. At least some of these are also retweeted in Skeptical Science Twitter page. ?Here's the archive for the research papers of previous weeks. If this sort of thing interests you, be sure to check out A Few Things Illconsidered. They also have a weekly posting containing lots of links to new research and other climate related news.

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Comments 1 to 22:

  1. Cohen et al is interesting. GISS agrees that parts of the NH have shown winter cooling on 1988-2010: [Map] Apart from Siberia, the effect disappears on the annual plots: [Map] Does this contradict polar amplification? Probably not, the zonal mean trend graph has a slight dip at 50N, but doesn't go negative, and is strongly positive at the pole. (While their maps are consistent with GISTEMP, Figure 1(b) is probably rather misleading, being based on the a short times span of the hopelessly incomplete CRUTEM3 data).
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  2. This is hands down my favorite feature one the web and each weekly installment is like a Christmas present -- nice to see the broadcast on more channels. Thanks!
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  3. What I find curious are Cohens claim of overall NH cooling since 1988. In at least most of Scandinavia and large parts of the US, the exact opposite is the case, except for winters 09/10 and 10/11. Seems that Cohens forecast for the 2011/12 Northern European winter was a warm one, just like the MET office forecast. Spot on so far. Funny to note that Piers Corbyn, the favorite forecaster of the Mayor of London, who lucked out last year, failed miserably this year. The MSM didn't print anything on that failure, though, as they only hassle the MET office, not the professional disinformers.
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  4. Piers Corbyn would probably be a worthwhile subject for a rebuttal, seeing as how he always seems to predict great freeze-ups and is favoured by quite a few naive so-called skeptics : who prefer his secretive astrology to proper science. No surprise there, then...
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  5. Looking at these posts makes one appreciate just how staggering the amount of information the IPCC processes must be. Likely there is a degree of pre-filtering provided by the amount of subsequent attention various papers attract, but I've seen some fairly obscure references in the IPCC reports as well. It is also interesting to note that 'anti-consensus' papers seem to get published fairly frequently... which runs against 'skeptic' claims of a 'grand conspiracy to hide the Truth' (though the total number of papers being published also shows how absurd that is), but also indicates more skeptical scientists than I'd thought were still about. Ironically we seem to hear alot more about the ones who publish seldom or never but spread disinformation to the media.
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  6. Piers Corbyn is taking part in a weather forecasting accuracy assessment organised by the BBC, along with others, including Joe Bastardi and The Met Office.
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  7. Hi PaulD @6, That assessment bothers me. How do we know that Corbyn and Bastardi are not using the numerical weather prediction model guidance, perhaps even the exact same guidance that the Met Office is using? I do not like this idea one bit, is is going to be too easy for Corbyn and Bastardi to cheat. Unless the officiators stipulate that they see the output from Corbyn's algorithm to make sure that his forecasts are consistent with his own methodology. Do you perhaps know where we can find out more about this assessment? Thanks.
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  8. As someone who has been assessing Corbyn's forecasts for some years, I have long suspected (though it's unproven)that he updates them based on latest numerical model guidance - his about turn with regards December 2011 for Britain (he went from the coldest on record, to an unsettled, 'zonal' month) appears to be in keeping with this belief. When all model guidance went against him, he issued a completely new forecast which, coincidently went aog with what the modls (and the MetO and others) were indicating. I don't know which forecasts he will be providing for this weather test: the ones he issues months in advance or the ones he issues at the start of each month (which invariably tend to be more accurate for the first 2 weeks than the latter 2). But I am confident those involved know what they are doing and that the final assessment will be fair and open.
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  9. Re: the weather forecasting test: All I know is that it is starting about Feb this year, will last 3 years or so and is being assessed by the Royal Meteorological Society and the Royal Statistical Society. I think the agreement is to do short term forecasting 1 to 5 days. The Met Office don't believe seasonal forecasting is statistically accurate enough.
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  10. Shocking news! Tang and Leng 2012 find evidence for negative correlation between 'normalized cloud cover anomaly' and 'normalized temperature anomaly:' More cloud cover does indeed mean less warming. They studied Eurasia over the timespan 1982-2009; there is no hint in their data (see their Figure 3) of anything even slightly resembling cosmic ray flux. Surprise: It's not cosmic rays.
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  11. @10: "More cloud cover does indeed mean less warming." SURPRISE: Clouds aren't a positive feedback (means low climate sensitivity).
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  12. #11, CoolCloud, that conclusion cannot be made based on a regional study.
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  13. Just a drive-by, Ari. Hence the screen name of choice. Edit: User CoolCloud is a sock-puppet of user Dale.
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  14. A nicely balanced selection of abstracts allowing us to glimpse more directly the complexity of the science. The strong point of such a presentation lies in its invitation to the reader to address the science directly and make up his own mind. I'd certainly like to see more presentations like this regardless of any apparent relationship to the consensus or contrarian perspective as per observations by CBD @ 5.
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  15. Ari#12, DB#13: CoolCloud jumps to a conclusion without reading the paper (or even the abstract): Our results suggest that the variance of summer temperature is partly explained by changes in summer cloudiness. This has nothing to do with feedback and even less to do with sensitivity. The motto of denial-world seems to be: Don't sweat the details.
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  16. I am confused by such a bag of papers. Surely the purpose of this site is to expose the skeptical and anti-AGW viewpoints against the consensus as largely BS (bad science). Are we to believe that the papers showing cooling for significant periods and insignificant Antarctic snowmelt since 1979 are peer reviewed good science? If so how are we as non-climate scientists to judge whether this post has any value when it seems to minimize or even go against the generally agreed consensus that AGW is real and drastic action to reduce CO2 emissions is required now.
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  17. victull: This is a summary of recent research, cross-posted from Ari's AGW Observer. It is not meant as a review of said papers, but it is a great way to see what is current across a wide range of publications. If you find an item of interest, you can often go directly to the full text of that particular article for the details.
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  18. victull: I'm speaking off the cuff here but if I recall correctly most ice loss occuring in Antarctica is due to increased glacier calving at sea level, not increased snow melt.
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  19. #16, victull, this compilation of papers contains those papers that I have found interesting during last week. All the papers above have been peer-reviewed but I have no idea if they are good science or not (I don't even know, what is meant by good science). I don't see obvious mistakes in them, so I think they might contribute to our body of knowledge. I don't see none of these papers going very strongly against the mainstream climate science. It is not to be expected that global warming happens everywhere all the time, so we can have parts of Eurasia cooling during winters and global warming continuing at the same time. I'm not quite sure if I even expected that Antarctic surface snowmelt would have been increasing. If I have understood correctly, Antarctic mass loss is mostly occurring by increased ice flow and warming sea melting ice from the bottom. I don't think that surface snowmelt is important factor there.
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  20. @16, 18, 19 As I mention in the paper, snowmelt plays an insignificant role in the mass budget of Antarctica. Mass is gained by snowfall and lost by calving of icebergs. Antarctica is simply too cold for significant melting. Moreover, almost all meltwater refreezes in the firn so that no contribution to sea level is made. However, snowmelt is important to quantify because it plays a role in the breakup of ice shelves. An insignificant change in meltwater volume since 1979 may hint to the importance of basal melting by warm ocean water in the recent breakups of ice shelves in the Antarctic Peninsula. Or, alternatively, ice-shelf breakup is preconditioned by melt over time scales longer than the 31 years assessed in the paper.
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  21. Hey, thanks for stopping by to clarify and reiterate, Peter (or Dr. Kuipers Munneke, if you prefer). The Arctic seems to get all the press; it's nice to hear voices from the other end of the Earth.
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  22. Day et al. have published a correction to their paper "The impact of a seasonally ice free Arctic Ocean on the temperature, precipitation and surface mass balance of Svalbard". Their abstract says that: "This experiment results in a 3.5 m water equivalent increase in Svalbard's SMB compared to the present day." The number 3.5 m is an error, it should be 0.35 m.
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