Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2189  2190  2191  2192  2193  2194  2195  2196  2197  2198  2199  2200  2201  2202  2203  2204  Next

Comments 109801 to 109850:

  1. Climate change: Water vapor makes for a wet argument
    johnd - I am sadly beginning to feel that you are being deliberately obtuse on this thread. You can certainly feel back-radiation and it's effects. Go outside on a warm night, turn your face to the sky. Then, for comparison, go inside to your kitchen, open the freezer, and face that from a foot away (outside the downdraft). You will feel the difference! I tend to use the back of my hand for this - for some reason I find that's pretty sensitive to thermal radiation, and I can even to some extent navigate in the dark - picking out doorways and cooler windows directionally, even though the air temperature doesn't change based on orientation of my hand. The temperature at any location is the sum of all the inputs - conduction from the ground, back-radiation from the sky, etc. As to CO2 distribution - there are certainly +/- 1 to 2% regional variations, as shown here: But given the rates of diffusion of gases, that's not going to have a distribution effect over a few meters - it takes kilometers of distance to induce a diffusion time delay. The first meter of air will not have a different concentration of CO2 than the next 2-3 meters unless you're playing with a CO2 fire extinguisher. Water vapor, due to it's state changes and extreme temperature sensitivity (and the fact that it adjusts to local conditions over hours or days, not centuries like CO2) is much more varied in distribution. Think 'clouds'. Enough said here. Johnd - the effect you had issues with (cold ground air) is what's behind radiation fog; there is no mystery there whatsoever. Look it up. Your issues on this thread have become more and more murky, to the extent that I (and perhaps others) can no longer tell what you are concerned about. The core of this thread is that water vapor is a powerful greenhouse gas with a short time constant - evaporating or condensing very quickly due to local temperature changes. This makes water vapor primarily a feedback, not a forcing, as other factors such as CO2 are much more long-term; water vapor adapts to and amplifies those relatively fixed factors. End of discussion for me, johnd.
  2. Should The Earth Be Cooling?
    Ned and Rob, Thanks for the great posts. Research has found that global SAT anomalies are best correlated with El Nino/La Nina indices when they lagged said indices by about 5-6 months. Specifically, "Christy and McNider [1994] and Angell [2000] show that the entire troposphere warms up with an overall lag of 5 to 6 months, but the lag is slightly less in the tropics and greater at higher latitudes." (from here) . DeepClimate undertook an analysis and identifed a 6-moth shift. So the marked impact on global SATs from the current (and quite strong) La Nina should be felt in the next two to three months.
  3. Skepticalenergyguy at 02:34 AM on 18 September 2010
    Human CO2 is a tiny % of CO2 emissions
    Who is going to replace CO2 with H2S or HCN? That can't and won't happen. CO2 is not poisonious and naturally occurs with our existence. So the population of the world has almost tripled in the past 50 years which will of course increase the CO2 emitted into the atmosphere. What's the solution, global birth control? Genocide? The earth has naturaly cycled through significant temperature changes throughout it's creation. Does our data from the last 200 years really tell us that our incremental affect of CO2 is causing the global warming, or like I said previously, this is a natural cycle of the planet?
  4. What's happening to glaciers globally?
    It does appear that Fig1 is a bit of a dud if you're looking for an accurate representation of global glacier records. UNEP/WGMS put out a joint report (http://www.grid.unep.ch/glaciers/) that has a global graph (Chap 5, Fig 5.9). You could use that. The problem is you have to acknowledge that mass balance loss was as fast in 1945-1955 as it was in the past decade. The final sentance needs to be amended if you want to represent the true picture. I suggest it ends ".....which has returned to the 1940's rate". Looking at Fig 5.1 suggests to me that any data going back beyond 1940 is really only a European (and to a lesser extent US) record.
  5. Himalayan Glaciers: Wrong Date, Right Message
    Barry @7, You just beat me to it! There is now a version 4.1 of the same incredibly informative talk available here is to vers. 4.1, but I see that there is now a version 4.2 out.
  6. Should The Earth Be Cooling?
    #22: Your graph puts these brief 'coolings' into perspective as the short-term noise superimposed on a long term cycle. That's a pretty basic concept in signal or time series analysis. I suppose a denier would look at the seasonal decrease in monthly atmospheric CO2 and conclude that there is a downwards trend: for 5 months out of 12, CO2 concentration is decreasing. Problem solved! Yet the peak and the average each year go up. Same picture: short-term variation superimposed on a long-term increase. Yooper had it exactly correct: The trend's the thing.
  7. Video update on Arctic sea ice in 2010
    I find it astonishing that people with no arctic experience would challenge the observations of an expert like Dr. Barber. If he says that the ice was expected to be thicker, that is what was expected. It is an extraordinary claim to suggest that Dr. Barber is wrong and data needs to be provided to support the claim, not just "I doubt it". He did not provide the background information because the talk was to experienced ice scientists who know the background information.
  8. Himalayan Glaciers: Wrong Date, Right Message
    Re: thingadonta (8) Got a source for your apparent quote? Or did you just make that up? The Yooper
  9. Himalayan Glaciers: Wrong Date, Right Message
    "the likelihood of global warming disappearing by 2035 and perhaps sooner is very high if the earth keeps stabilising at the present rate".
  10. Should The Earth Be Cooling?
    Here is another chart that I did. Without even trying very hard I identified 5 different points where "CO2GHG theory has been in trouble." It's actually pretty easy to pick out sharp declines over short time periods. And, it seems to get a little harder to identify sharp declines as you move forward in time.
  11. Should The Earth Be Cooling?
    Rob Honeycutt writes: we're winding down the hottest year in the temperature record, in a negative PDO, during a solar minimum and in a La Nina. Agreed 100% on the rest of your post, but the "in a La Nina" bit is somewhat confusing since we started out the year in a (moderate) El Nino cycle and temperatures typically lag ENSO slightly IIRC. My guess is that now that La Nina conditions have returned we'll see temperatures drop a bit from the highs of recent months. Nonetheless, Rob's main points are right -- KL's selection of 2002 is obvious cherry-picking, and his claim that this means "trouble" for AGW is just nonsense.
  12. Should The Earth Be Cooling?
    Regarding oceanic heat content. (OHC). From Palmer et l. (2010; "State of the climate in 2009" report): "Even so, errors are too large to obtain reliable trends over a few years. However, the three curves all agree on a significant decadal warming of the upper ocean since 1993, accounting for a large portion of the global energy imbalance over this time period (Trenberth 2009), and the three sets of maps (not shown) from which the curves are produced show similar largescale features." For the same period covered in the above graphs (from 1979 onwards)0-700 OHC has increased by about 10x10^22 J [From Fig. 3.9 in the "State of the climate report"] That said, their Fig. 3.8 gives a different picture, so I am not entirely sure which one to trust.
  13. Should The Earth Be Cooling?
    You also have to believe that everything else should stop happening under CO2 warming. Skeptics don't believe in interannual variability, which is why they conflate short-term weather phenomena and climate. No, it has to be monotonically warming, year-by-year, or there's a 'problem with AGW'. Ask a skeptic what the minimum period is to get a bead on climate and they'll say nothing, or that 30 years is wa-a-y too short. It's like asking them when the Medieval Warm Period was supposed to have occurred. Makes them silent or uncomfortable.
  14. Himalayan Glaciers: Wrong Date, Right Message
    It might be worth pointing out that rhe mistake wasn't spotted by some steely-eyed skeptic auditor, but by one of the IPCC AR4 authors, J. Graham Cogley. List of AR4 authors J. Graham Cogley's view on the mistake:
    This was a bad error. It was a really bad paragraph, and poses a legitimate question about how to improve IPCC’s review process. It was not a conspiracy. The error does not compromise the IPCC Fourth Assessment, which for the most part was well reviewed and is highly accurate.
    http://web.hwr.arizona.edu/~gleonard/2009Dec-FallAGU-Soot-PressConference-Backgrounder-Kargel.pdf [p. 74] Cogley backs the IPCC AR4, despite this error.
  15. Should The Earth Be Cooling?
    Ken Lambert@14... "Just the fact that we are all niggling about whether the Earth is slightly heating or cooling over the last 8-15 years, or whether it is statistically significant is pretty good proof that the theory of CO2GHG forcing as the main driver of global warming is in serious trouble." That statement makes absolutely no sense to me at all. By that logic the "theory of CO2GHG forcing" would have been "in trouble" several times over the past 50 years. Look at the temperature record and plot out all the 8 and ten year trends. I just got on the Wood for Trees site and started imputing dates. You literally have to go through each possible year to present and pick out 2002 to get the lowest trend. That is by definition cherry picking. Here are the results of those searches... Not only that, but to claim that CO2GHG theory is in trouble you have to completely ignore the fact that we're winding down the hottest year in the temperature record, in a negative PDO, during a solar minimum and in a La Nina.
  16. Should The Earth Be Cooling?
    mdenison makes good points about the longer term (millennial or longer) cooling trend. Wanner et al. 2008 provides a nice overview of climate change from the mid-Holocene to the start of the industrial era. There was a long, slow cooling trend in NH summers, due to orbital geometry, plus more spatially complex changes in humidity, winds, and temperatures elsewhere. Read the paper for all the details, but the following figure from the paper (click to enlarge) provides a nice overview. Figure 18 from Wanner et al. 2008. Spatial synthesis: global climate change for the preindustrial period (AD ~1700) compared to the Mid Holocene (~6000 cal years BP). People refer to the Mid-Holocene as a "warm period" (I just did in a comment in another thread!) so it's tempting to guess that you could just invert all those changes and get a pretty good idea of where we're headed, warming-wise. But unfortunately that won't work, since the change from Mid-Holocene to modern conditions was driven by orbital geometry, which involves changing the spatial-seasonal distribution of solar irradiance, rather different from the spatial-seasonal distribution of warming caused by increased CO2.
  17. What's happening to glaciers globally?
    BP, obviously the Holocene Thermal Maximum was a warm period particularly in the mid- to high-latitude Northern Hemisphere, thanks to Milankovich geometry. That obviously doesn't apply to current conditions. Of course, if we haven't already done so we'll certainly be exceeding HTM temperatures soon enough, then exceeding MIS-5e (Eemian) temperatures as well. That doesn't bode well for glaciers. It seems unlikely that the present rapid retreat will be reversing itself any time soon.
  18. beam me up scotty at 00:50 AM on 18 September 2010
    Himalayan Glaciers: Wrong Date, Right Message
    How seriously should we argue with people who would pick a single event (cold winter, IPCC error etc.) to refute the undeniable(!) and observable warming and ocean acidification?
  19. Should The Earth Be Cooling?
    ClimateWatcher, trends from 2000 to present for all temperature data sets show warming. Same goes if you select any year prior. There's a mix of results up to 2005. Then, from 2006 onwards, all data sets show warming again. Here are the trends from 2006. HadCRUt - 1.8K/century GISTEMP - 2K/century UAH - 4.6K/century RSS - 4.1K/century As you can see, warming has recommenced at an alarming rate. Or....? The top post is about climate trends (20 - 30 years). As your time periods are not climatic, what is it that you are talking about? Even in a clearly warming world, we will always get reruns of 'no warming since 1998'. The meme will stay the same, only the date will change. 2002 was the favourite for a while because a year or so ago, all the data sets showed a negative trend. In a few more months the 'skeptics' will be obliged to cherry-pick a more recent year.
  20. Why positive feedback doesn't necessarily lead to runaway warming
    68, TTTM: It's true that the immediate effect of convection is to move heat upwards. However, the problem remains that the altitude at which the water vapor condenses is still far below the photosphere for the relevant IR photons, so those photons have to try for their chance at escape just like all the other IR photons. That rate of escape is set by the temperature of the surface of the IR photosphere. This in turn is set by: a) the temperature at ground level; and b) the adiabatic lapse rate. Now, actually, it occurs to me that you might have a point: The adiabatic lapse rate is reduced by increased humidity; so if the humidity increases, the temperature at the photosphere will be increased, so it will radiate more. Of course, increased humidity also means more greenhouse gas in the atmosphere - but if it's below the photosphere, it shouldn't matter. I'll think it over...
  21. What's happening to glaciers globally?
    mspelto is right to note that WGMS provides a good source for global data on glaciers over the past few decades. I agree with Grim_Reaper's point that the data plotted in figure 1 of this post are probably not representative of the global trend in glacier mass balance. I give Berényi Péter a hard time about this constantly, in other contexts -- you can't draw reliable conclusions about a global mean from a sample with an ad-hoc spatial distribution like this. That's not to say that glaciers aren't retreating in most places; they obviously are. But quantifying the global mean trend for that is a difficult undertaking.
  22. What's happening to glaciers globally?
    The bottom line is that glacier variations are largely dependent on localized conditions but that these variations are superimposed on a clear and evident long term reduction in glacier volume which has accelerated rapidly since the 1970s Yet glaciers are still larger today than in 12 other several hundred years long periods during the Holocene, initiated and ended by abrupt changes each time. Ten thousand years could reasonably be called "long term", if not on a true geological time scale, at least compared to the 160 or 40 year flashes you are talking about. We should always pursue the big picture, don't we? The Holocene, July 2006 vol. 16 no. 5 pp. 697-704 doi: 10.1191/0959683606hl964rp Multicentury glacier fluctuations in the Swiss Alps during the Holocene Ulrich E. Joerin, Thomas F. Stocker and Christian Schlüchter "The radiocarbon ages of tree fragments and peat discs found on proglacial forefields indicate 12 phases of glacier recessions during the Holocene. Locations and type of occurrence of the dated samples show that trees and mires grew where glaciers exist at present and, therefore, glaciers were smaller at that time."
  23. Why positive feedback doesn't necessarily lead to runaway warming
    #67 : "No Increasing convection wouldn't actually do anything to cool off the planet." Convection takes water vapour from the surface high into the atmosphere where it condenses back into water losing a significant amount of latent heat which is then radiated away. Its one of the most important heat transfer mechanisms in our atmosphere.
  24. Should The Earth Be Cooling?
    There is a long term cooling from the holocene maximum due to orbital forcing. Over a millenium it mounts up. I have only looked this up on Wikipedia however. I believe at present the effect is smaller than in the past. A small fall in temperature over the last 1000-2000 years as indicated by proxy reconstructions and models is consistent with this. If someone has literature references giving reasons for the trend of the last 1000-2000 years, (eg. consistentcy with post holocene cooling) then it may be worth adding to this article. The literature may posit other reasons/observations worth posting too for a millenial scale trend.
  25. Should The Earth Be Cooling?
    muoncounter #7 Just the fact that we are all niggling about whether the Earth is slightly heating or cooling over the last 8-15 years, or whether it is statistically significant is pretty good proof that the theory of CO2GHG forcing as the main driver of global warming is in serious trouble. My understanding of events such as ENSO, La Nina, PDO, AMO are internal to the Earth system - they are re-distributors of heat energy already there; and not a cause of external forcing imbalances globally gaining or losing heat. The 11 year cycle in the TSI curve is well documented and effectively a +/-0.5W/sq.m ripple on complex long term Solar-Earth cycles. In the absence of other AG forcings (including aerosol albedo effects) we need to know the value of TSI which produces no heating or cooling of the Earth system. Then we can easily calculate whether a reduced TSI (excluding the 11 year ripple) is above or below the 'zero' forcing value. Just showing a downtrend in TSI (as in the chart above)means that heat gain from solar radiation is less than it was; but not necessarily less than the 'zero' forcing value - which would still mean net heat gain but at a lower rate from TSI alone rather than cooling (or heat loss). You then need to assess the values of the other AR4 AG forcings - the most uncertain being cloud and aerosol albedo cooling (currently 2005 at -1.2W/sq.m with wide error bars). I would be having a small wager on reduced TSI warming, greater albedo cooling and a smaller CO2GHG warming effect than theorised by the IPCC all producing flat temperatures over the last 8-10 years; further evidenced by little gain in OHC as measured by an imperfect Argo.
  26. Why positive feedback doesn't necessarily lead to runaway warming
    TTTM: - Increasing albedo would indeed reduce the radiation absorbed by the Earth, and would help curb the radiative imbalance. Lindzen suggests that this may be happening; as far as I can tell, right now the bulk of the evidence seems to be against him. It's not a crazy idea; it just doesn't seem to be what's happening. - Increasing convection wouldn't actually do anything to cool off the planet. Convection can only carry warmth as far as the atmosphere goes, whereas to cool the planet the warmth must depart into space. Analogy: You can depopulate the planet with space ships but not with airplanes: They don't go far enough.
  27. Should The Earth Be Cooling?
    Re: ClimateWatcher (12)
    "Great. Don't say that it's not cooling though, because using this criteria, you'll have to wait thirty years."
     To reiterate, using data from 1979 to 2010: RSS_LT 0.163 K/decade or 1.63 K/Century RSS_MT 0.099 K/decade or 0.99 K/Century RSS_TS 0.005 K/decade or 0.05 K/Century RSS_SL -0.313 K/decade or -3.13 K/Century (stratospheric cooling, as predicted by the physics of greenhouse gases) Using data from 1900 to 2000: CRU: CRU 0.80 K/century (eyeball Mk. 4) CRU SST 0.70 K/century (eyeball Mk. 4) GISS: GISS 0.80 K/century (eyeball Mk. 4) To paraphrase Shakespeare: the Trend is the thing. The trends, using 30 or more years of data, all show the hallmark of the effects of GHG accumulations (significant warming in the oceans and troposphere, cooling in the stratosphere, northward expansion of the Hadley cells, 10 mile-per-year northward relocation of the northern polar jet, mass-loss in the GIS, the WAIS AND the EAIS, acidifying seas, 40% loss of oceanic phytoplankton in the last 40 years, etc). And doing it over the last 30 years, during which TSI has been flat or down, GCR's have been flat, UHI invalidated and aerosols have been retarding the forcings from GHG's to some degree (meaning: temperature increases and resultant negative effects should've been worse than observed). Therefore, looking at 30 or more years of data which also covers the period to date, IT'S NOT COOLING! This focus on short-term noise/variability does you a great disservice. The Yooper
  28. Himalayan Glaciers: Wrong Date, Right Message
    The paper by Immerzeel (2010) was already discussed here in the article "Return to the Himalayas" on 29 June 2010 by Doug Bostrom. I wrote some comments about IPCC AR4 and Barnett (2005) there. Some earlier discussions about the paper by Barnett (2005) was made as comments to the blog article "The IPCC's 2035 prediction about Himalayan glaciers" posted on 21 January 2010.
  29. Why positive feedback doesn't necessarily lead to runaway warming
    "So if you don't change the incoming part of the radiation from the sun you need to warm up by a certain amount to get back in that radiative equilibrium." Or increase cloud cover (albedo) or increase convection, surely.
  30. Should The Earth Be Cooling?
    >Unless you're looking at all of the data available, or at least >snippets of 30 years or more (or you can demonstrate high >correlation values that are statistically significant), you're >wasting our time. Great. Don't say that it's not cooling though, because using this criteria, you'll have to wait thirty years.
  31. What's happening to glaciers globally?
    JMurphy, that'll teach me for skim reading. My point still stands though: Is this geographically limited sample sufficient to work out the global picture? I'd feel far more comfortable if those 400+ glaciers were spread around the world (as with the more recent data). For me, this undermines the authority of an otherwise excellent graph, and make it a target for sceptics.
  32. Himalayan Glaciers: Wrong Date, Right Message
    As mspelto said, most of glaciers to the south of the Himalayas accumulate snow in the summer monsoon season. But perhaps the word "summer" is ambiguous. In the tropical monsoon Asia, the maximum in the annual cycle of air temperature often occurs in the pre-monsoon season (April to May in India, still dry until the onset of monsoon rain in June). I think that glacier melt water takes the largest fraction of streamflow in the pre-monsoon season (though I do not have appropriate data ready to assert this). This is a story about the seasonal cycle and not about climate change.
  33. Himalayan Glaciers: Wrong Date, Right Message
    are retreating All you have to do is read the abstract of this and wonder about all this. It states ice loss was rapid in the 60s. It also states that precip rates are down. then it says summer temps are warmer. Question class. if you decrease ice mass in an area what would you expect the temperature to do? Yes it would go up. that is exactly why the most extreme temperature changes are seen on the margins of ice areas. It doesn't take a scientist to figure that out.
  34. Should The Earth Be Cooling?
    #10: "ocean heat content (or if you prefer, ocean cold content-just to be language-neutral)" Nope, it would be heat content. Cold is the relative lack of heat energy and therefore not something that can be contained. Just to be language-correct. Why would non-consensus over OHC matter in this context? We're not talking about a global energy balance; we're talking about the observable temperature increase which already includes whatever the oceans are doing.
  35. Himalayan Glaciers: Wrong Date, Right Message
    The issue of "500 million people" should perhaps be put off. It is confusing to conflate the Himalayas in the proper sense in the issue of the mistaken outlook of the glaciers on one hand, and the catchments of various rivers originating in the central Asian highlands including, but not limited to, the Himalayas, in the issue of vulnerable population, on the other hand. Also, if the broken link "Kehrwald 2008" refers to the paper of Kehrwald et al. 2008 in Geophysical Research Letters 35, L22503, the reference to the paper in this context is inappropriate. Kehrwald et al.'s expertise is in scientific estimates of mass balance of glaciers. Remarks about human population in its "implication" section were just drawn from the (questioned) Asian chapter of the IPCC AR4 WG2 (together with the mistaken outlook of the Himalayan glaciers), and also from the paper by Barnett et al. 2005 (Nature 438, 303-309) which was the main source of the information used by AR4 about the issue of population. The numbers in Barnett 2005 are often communicated as the numbers of people who depend on glacier melt water, but it is not. In one context, it is the number of people who depend on snowmelt water and glacier melt water together, and it is likely that snowmelt is more important in the majority. In another context (northwestern China), a large number is the total population of a region which has parts where glacier melt water is important. A much better estimate of the vulnerable population has been made by Immerzeel et al. 2010 Science 328, 1382-1385. I think that this paper should be cited instead of Kehlwald 2008 and Barnett 2005. But note that the target of this paper was 5 large river basins. It did not contain analyses of small inland river basins where glacier meltwater is likely to be crucial, though population is not as large there as in large river basins.
  36. Himalayan Glaciers: Wrong Date, Right Message
    Himalayan glaciers draining south into India, Pakistan, Nepal and Bhutan are increasingly being utilized for hydropower. One key point is that for the southern facing main Himalayan Range of India-Nepal-Bhutan the wet season is also the melt season. The summer monsoon leads to most of the melting low on a glacier and the accumulation high on a glacier. thus, unlike other areas low flow is not during the summer melt season and meltwater is not as critical to streamflow. The retreat is ongoing and substantial for almost all of the glaciers outside the Karokoram Range.Zemu Glacier, Gangotri Glacier and Satonpanth Glacier for example both of which feed hydropower.
  37. What's happening to glaciers globally?
    Since 1965 we have a strong series of mass balance from around the globe that Switzerland provides less than 10% of the data for. The WGMS collects this data each year, for 2008 there were about 100 glaciers that have been reported so far, three from Switzerland. I report 12 each year from the United States for example. Robert makes a good point about the type of precipitation. On temperate glaciers even if you get some rain events in the winter the water is stored in the deep snowpack, and almost everything falls as snow. However, we have observed one issue, and that is as the snowpack warms earlier in the winter season, fewer ice lenses are formed on the Juneau Icefield. The result is less meltwater in April and May is retained as refrozen ice lenses.
  38. What's happening to glaciers globally?
    Grim_Reaper, the document you link to also mentions the records of 143 glaciers in Italy from a date of 1820. thingadonta, are you suggesting that glaciers don't move, and that Otzi has been in the same location for the last 5000 years ?
  39. What's happening to glaciers globally?
    thingadonta, glaciers respond, among other things, to temperature. Recently it has been warming and glaciers are responding to it, whatever its cause might be. Little doubt about this, i guess, and it's what this post is showing. By the way, who said that there was no ice where and when Otzi died? Could it be so well preserved if not kept at very low temperatures from right after his death?
  40. What's happening to glaciers globally?
    Yes and glaciers in Europe are only now exposing ancient ruins of Romans (book reference 'the Chilling Stars'), the Ice Man (Ozste) etc, which means glaciers have just now got back to where they were several times in the last several thousand years, with no nasty human c02 emissions.
  41. Should The Earth Be Cooling?
    One major wild card I would add to your discussion is ocean heat content (or if you prefer, ocean cold content-just to be language-neutral), and the current disagreements (ie non consensus) surrounding this.
  42. What's happening to glaciers globally?
    I found this document (http://www.ibcperu.org/doc/isis/7076.pdf) which confirms there's data for 300 glaciers starting with 1850, but they're all Swiss. Can you really get a global picture from just 1 small country?
  43. What's happening to glaciers globally?
    Oh, and the graph is determined by using over 300 glaciers (as far as I can make out), if Table 1 in the original paper itself is anything to go by - but I have only skimmed over it.
  44. What's happening to glaciers globally?
    Grim_Reaper, have a look at another graph which includes the above but also data from all glaciers since 1980, and you will see the same downward trend : NOAA Glacier Mass Balance
  45. What's happening to glaciers globally?
    Figure 1 (Global glacier volume) looked great to me at first. Then I started wondering how they managed to calculate the volume all the way back to 1850. From what I can tell, more than half that graph is extrapolated from just 30 glaciers, all of which are based in Switzerland. Can you really do this and come up with a reliable result?
  46. Climate change: Water vapor makes for a wet argument
    John, it comes from BOTH sun and backradiation as has been explained. Why is it so hard to understand this? You can sense the backradiation if you go into your backyard at night - note the lack of instant freezing to death. However, your sensors are more likely to notice the conduction from your warm body to the cooler night air. Have you bothered to compare ground cooling rate between clear and cloudy night yet?
  47. Should The Earth Be Cooling?
    You have to be very careful about any "trend" in the TSI data, because of the strong 11-year cyclic nature of it. Any trend should be based on an integer number of cycles, so 22 or 33 or 44 years. Otherwise the partial cycle will influence the trend. That said, the bit of extra cycle you chart would tend to influence the trend upward, and yet the overall trend is down...
  48. Climate change: Water vapor makes for a wet argument
    John, this is getting a bit repetitive but I will try... At the surface, radiation is being received as short wave from sun, and long wave from the atmosphere. The radiation is absorbed by atoms/molecules in that surface (at top for ground, in first few metres for water). This radiation energy converts to added kinetic energy for these atoms. Collectively this is heat, and what the thermometer measures. Conduction comes into play. The energy is transferred, atom to atom, both downward below the surface and to molecules of the atmosphere at the boundary, which collide with others to transfer energy up. In liquids, some of that energy also goes into evaporation. So the surface loses energy and thus is cooled by those processes. The amount of energy the can be moved away by conduction and evaporation is strictly limited by physical laws. As energy is absorbed, more and more radiation energy is converted to kinetic energy in the atoms. However, moving atoms (or more to point, the charged particles of the atoms) lose energy by radiation. The temperature of surface (the amount of kinetic energy in the atoms) stops rising when the losses by radiation match the energy coming in. Surface radiation goes up. For the temperatures at the earth surface, this radiation is long wave as opposed to the short wave coming in. The atmosphere is transparent (it doesnt absorb) to short wave, but GHG do absorb the longwave, convert to kinetic energy and so heat the atmosphere. Moving particles again, so atmosphere emits radiation, some of which goes down to the surface again. Its not an efficient emitters because atmosphere re-absorbs radiation, then emits again and so on. This is the backradiation. What happens to your thermometers? Well in day time, shortwave from sun and backradiation both heat. Surface heats faster than atmosphere because it absorbs the radiation whereas atmosphere is only heated by conduction and the limited absorption of surface radiation by GHG. Conduction is more important closer to the ground. At night, the surface continues to radiate effectively for its temperature but now only warmed by backradiation. As it is efficient radiator is cools faster than atmosphere and again conduction works in reverse, cooling air closer to the ground. As temperature of ground drops, surface radiation reduces and so back radiation also is reduced but not hugely as whole thickness of the atmosphere is involved in radiation, absorption and re-radiation. You can see the relative night time drops if you go to site that actually measures the radiation as well as the temperature. And in case I need to say it... A thermometer does not measure radiation - it may measure the energy converted to atomic motion by an absorber however.
  49. Climate change: Water vapor makes for a wet argument
    scaddenp at 07:20 AM, Phil, on the contrary, I think we are getting somewhere. So, a thermometer lying on the ground, or a barefoot kid does not measure what radiation instruments measures. What they both measure is the result of solar radiation being absorbed by matter or objects on surface, sufficient radiation to heat the surface to the point a bare foot kid would be unable to stand still for fear of burning his feet, or as I mentioned earlier, enough to fry an egg in some cases. That leads us back to the question as to where does the energy come from that drives evaporation, is it that heat absorbed from the solar energy that can burn the soles of the kids foot, or is it the back radiation that he is unable to sense as it can only be measured by radiation instruments?
  50. Climate change: Water vapor makes for a wet argument
    KR at 12:34 PM, regarding how well CO2 is mixed in the atmosphere, you will find this study of CO2 levels measured by surface stations interesting. http://www.atmos-chem-phys.net/8/7239/2008/acp-8-7239-2008.pdf In particular note what variations can occur over a few days, as well as the huge variations that occur over the course of the year due to seasonal conditions, up to or in excess of 50ppm, certainly very much more than a slight decrease, as well as how much the CO2 varies between locations. Given the processes that transport the CO2, the distribution of it has a lot in common with how heat is distributed as well as moisture, so would you say that they too are well and evenly distributed in the atmosphere. We know and accept that water must return to the surface to complete the hydrological cycle and so too does CO2. The amount of CO2 that is in the carbon cycle moving between the sources and sinks, all of them at the earths surface, is about 30 times that which is released by the combustion of fossil fuels.

Prev  2189  2190  2191  2192  2193  2194  2195  2196  2197  2198  2199  2200  2201  2202  2203  2204  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us