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2009 temperatures by Jim Hansen

Filed under: — group @ 17 January 2010 - (Français)

This is Hansen et al’s end of year summary for 2009 (with a couple of minor edits). Update: A final version of this text is available here.

If It’s That Warm, How Come It’s So Damned Cold? 

by James Hansen, Reto Ruedy, Makiko Sato, and Ken Lo
The past year, 2009, tied as the second warmest year in the 130 years of global instrumental temperature records, in the surface temperature analysis of the NASA Goddard Institute for Space Studies (GISS). The Southern Hemisphere set a record as the warmest year for that half of the world. Global mean temperature, as shown in Figure 1a, was 0.57°C (1.0°F) warmer than climatology (the 1951-1980 base period). Southern Hemisphere mean temperature, as shown in Figure 1b, was 0.49°C (0.88°F) warmer than in the period of climatology.

Figure 1. (a) GISS analysis of global surface temperature change. Green vertical bar is estimated 95 percent confidence range (two standard deviations) for annual temperature change. (b) Hemispheric temperature change in GISS analysis. (Base period is 1951-1980. This base period is fixed consistently in GISS temperature analysis papers – see References. Base period 1961-1990 is used for comparison with published HadCRUT analyses in Figures 3 and 4.)

The global record warm year, in the period of near-global instrumental measurements (since the late 1800s), was 2005. Sometimes it is asserted that 1998 was the warmest year. The origin of this confusion is discussed below. There is a high degree of interannual (year‐to‐year) and decadal variability in both global and hemispheric temperatures. Underlying this variability, however, is a long‐term warming trend that has become strong and persistent over the past three decades. The long‐term trends are more apparent when temperature is averaged over several years. The 60‐month (5‐year) and 132 month (11‐year) running mean temperatures are shown in Figure 2 for the globe and the hemispheres. The 5‐year mean is sufficient to reduce the effect of the El Niño – La Niña cycles of tropical climate. The 11‐year mean minimizes the effect of solar variability – the brightness of the sun varies by a measurable amount over the sunspot cycle, which is typically of 10‐12 year duration.

Figure 2. 60‐month (5‐year) and 132 month (11‐year) running mean temperatures in the GISS analysis of (a) global and (b) hemispheric surface temperature change. (Base period is 1951‐1980.)

There is a contradiction between the observed continued warming trend and popular perceptions about climate trends. Frequent statements include: “There has been global cooling over the past decade.” “Global warming stopped in 1998.” “1998 is the warmest year in the record.” Such statements have been repeated so often that most of the public seems to accept them as being true. However, based on our data, such statements are not correct. The origin of this contradiction probably lies in part in differences between the GISS and HadCRUT temperature analyses (HadCRUT is the joint Hadley Centre/University of East Anglia Climatic Research Unit temperature analysis). Indeed, HadCRUT finds 1998 to be the warmest year in their record. In addition, popular belief that the world is cooling is reinforced by cold weather anomalies in the United States in the summer of 2009 and cold anomalies in much of the Northern Hemisphere in December 2009. Here we first show the main reason for the difference between the GISS and HadCRUT analyses. Then we examine the 2009 regional temperature anomalies in the context of global temperatures.

Figure 3. Temperature anomalies in 1998 (left column) and 2005 (right column). Top row is GISS analysis, middle row is HadCRUT analysis, and bottom row is the GISS analysis masked to the same area and resolution as the HadCRUT analysis. [Base period is 1961‐1990.]

Figure 3 shows maps of GISS and HadCRUT 1998 and 2005 temperature anomalies relative to base period 1961‐1990 (the base period used by HadCRUT). The temperature anomalies are at a 5 degree‐by‐5 degree resolution for the GISS data to match that in the HadCRUT analysis. In the lower two maps we display the GISS data masked to the same area and resolution as the HadCRUT analysis. The “masked” GISS data let us quantify the extent to which the difference between the GISS and HadCRUT analyses is due to the data interpolation and extrapolation that occurs in the GISS analysis. The GISS analysis assigns a temperature anomaly to many gridboxes that do not contain measurement data, specifically all gridboxes located within 1200 km of one or more stations that do have defined temperature anomalies.

The rationale for this aspect of the GISS analysis is based on the fact that temperature anomaly patterns tend to be large scale. For example, if it is an unusually cold winter in New York, it is probably unusually cold in Philadelphia too. This fact suggests that it may be better to assign a temperature anomaly based on the nearest stations for a gridbox that contains no observing stations, rather than excluding that gridbox from the global analysis. Tests of this assumption are described in our papers referenced below.

Figure 4. Global surface temperature anomalies relative to 1961‐1990 base period for three cases: HadCRUT, GISS, and GISS anomalies limited to the HadCRUT area. [To obtain consistent time series for the HadCRUT and GISS global means, monthly results were averaged over regions with defined temperature anomalies within four latitude zones (90N‐25N, 25N‐Equator, Equator‐25S, 25S‐90S); the global average then weights these zones by the true area of the full zones, and the annual means are based on those monthly global means.]

Figure 4 shows time series of global temperature for the GISS and HadCRUT analyses, as well as for the GISS analysis masked to the HadCRUT data region. This figure reveals that the differences that have developed between the GISS and HadCRUT global temperatures during the past few decades are due primarily to the extension of the GISS analysis into regions that are excluded from the HadCRUT analysis. The GISS and HadCRUT results are similar during this period, when the analyses are limited to exactly the same area. The GISS analysis also finds 1998 as the warmest year, if analysis is limited to the masked area. The question then becomes: how valid are the extrapolations and interpolation in the GISS analysis? If the temperature anomaly scale is adjusted such that the global mean anomaly is zero, the patterns of warm and cool regions have realistic‐looking meteorological patterns, providing qualitative support for the data extensions. However, we would like a quantitative measure of the uncertainty in our estimate of the global temperature anomaly caused by the fact that the spatial distribution of measurements is incomplete. One way to estimate that uncertainty, or possible error, can be obtained via use of the complete time series of global surface temperature data generated by a global climate model that has been demonstrated to have realistic spatial and temporal variability of surface temperature. We can sample this data set at only the locations where measurement stations exist, use this sub‐sample of data to estimate global temperature change with the GISS analysis method, and compare the result with the “perfect” knowledge of global temperature provided by the data at all gridpoints.

1880‐1900 1900‐1950 1960‐2008
Meteorological Stations 0.2 0.15 0.08
Land‐Ocean Index 0.08 0.05 0.05

Table 1. Two‐sigma error estimate versus period for meteorological stations and land‐ocean index.

Table 1 shows the derived error due to incomplete coverage of stations. As expected, the error was larger at early dates when station coverage was poorer. Also the error is much larger when data are available only from meteorological stations, without ship or satellite measurements for ocean areas. In recent decades the 2‐sigma uncertainty (95 percent confidence of being within that range, ~2‐3 percent chance of being outside that range in a specific direction) has been about 0.05°C. The incomplete coverage of stations is the primary cause of uncertainty in comparing nearby years, for which the effect of more systematic errors such as urban warming is small.

Additional sources of error become important when comparing temperature anomalies separated by longer periods. The most well‐known source of long‐term error is “urban warming”, human‐made local warming caused by energy use and alterations of the natural environment. Various other errors affecting the estimates of long‐term temperature change are described comprehensively in a large number of papers by Tom Karl and his associates at the NOAA National Climate Data Center. The GISS temperature analysis corrects for urban effects by adjusting the long‐term trends of urban stations to be consistent with the trends at nearby rural stations, with urban locations identified either by population or satellite‐observed night lights. In a paper in preparation we demonstrate that the population and night light approaches yield similar results on global average. The additional error caused by factors other than incomplete spatial coverage is estimated to be of the order of 0.1°C on time scales of several decades to a century, this estimate necessarily being partly subjective. The estimated total uncertainty in global mean temperature anomaly with land and ocean data included thus is similar to the error estimate in the first line of Table 1, i.e., the error due to limited spatial coverage when only meteorological stations are included.

Now let’s consider whether we can specify a rank among the recent global annual temperatures, i.e., which year is warmest, second warmest, etc. Figure 1a shows 2009 as the second warmest year, but it is so close to 1998, 2002, 2003, 2006, and 2007 that we must declare these years as being in a virtual tie as the second warmest year. The maximum difference among these in the GISS analysis is ~0.03°C (2009 being the warmest among those years and 2006 the coolest). This range is approximately equal to our 1‐sigma uncertainty of ~0.025°C, which is the reason for stating that these five years are tied for second warmest.

The year 2005 is 0.061°C warmer than 1998 in our analysis. So how certain are we that 2005 was warmer than 1998? Given the standard deviation of ~0.025°C for the estimated error, we can estimate the probability that 1998 was warmer than 2005 as follows. The chance that 1998 is 0.025°C warmer than our estimated value is about (1 – 0.68)/2 = 0.16. The chance that 2005 is 0.025°C cooler than our estimate is also 0.16. The probability of both of these is ~0.03 (3 percent). Integrating over the tail of the distribution and accounting for the 2005‐1998 temperature difference being 0.61°C alters the estimate in opposite directions. For the moment let us just say that the chance that 1998 is warmer than 2005, given our temperature analysis, is at most no more than about 10 percent. Therefore, we can say with a reasonable degree of confidence that 2005 is the warmest year in the period of instrumental data.

Figure 5. (a) global map of December 2009 anomaly, (b) global map of Jun‐Jul‐Aug 2009 anomaly. #4 and #2 indicate that December 2009 and JJA are the 4th and 2nd warmest globally for those periods.

What about the claim that the Earth’s surface has been cooling over the past decade? That issue can be addressed with a far higher degree of confidence, because the error due to incomplete spatial coverage of measurements becomes much smaller when averaged over several years. The 2‐sigma error in the 5‐year running‐mean temperature anomaly shown in Figure 2, is about a factor of two smaller than the annual mean uncertainty, thus 0.02‐0.03°C. Given that the change of 5‐year‐mean global temperature anomaly is about 0.2°C over the past decade, we can conclude that the world has become warmer over the past decade, not cooler.

Why are some people so readily convinced of a false conclusion, that the world is really experiencing a cooling trend? That gullibility probably has a lot to do with regional short‐term temperature fluctuations, which are an order of magnitude larger than global average annual anomalies. Yet many lay people do understand the distinction between regional short‐term anomalies and global trends. For example, here is comment posted by “frogbandit” at 8:38p.m. 1/6/2010 on City Bright blog:

“I wonder about the people who use cold weather to say that the globe is cooling. It forgets that global warming has a global component and that its a trend, not an everyday thing. I hear people down in the lower 48 say its really cold this winter. That ain’t true so far up here in Alaska. Bethel, Alaska, had a brown Christmas. Here in Anchorage, the temperature today is 31[ºF]. I can’t say based on the fact Anchorage and Bethel are warm so far this winter that we have global warming. That would be a really dumb argument to think my weather pattern is being experienced even in the rest of the United States, much less globally.”

What frogbandit is saying is illustrated by the global map of temperature anomalies in December 2009 (Figure 5a). There were strong negative temperature anomalies at middle latitudes in the Northern Hemisphere, as great as ‐8°C in Siberia, averaged over the month. But the temperature anomaly in the Arctic was as great as +7°C. The cold December perhaps reaffirmed an impression gained by Americans from the unusually cool 2009 summer. There was a large region in the United States and Canada in June‐July‐August with a negative temperature anomaly greater than 1°C, the largest negative anomaly on the planet.

Figure 6. Arctic Oscillation (AO) Index. Positive values of the AO index indicate high low pressure in the polar region and thus a tendency for strong zonal winds that minimize cold air outbreaks to middle latitudes. Blue dots are monthly means and the red curve is the 60‐month (5‐year) running mean.

How do these large regional temperature anomalies stack up against an expectation of, and the reality of, global warming? How unusual are these regional negative fluctuations? Do they have any relationship to global warming? Do they contradict global warming?

It is obvious that in December 2009 there was an unusual exchange of polar and mid‐latitude air in the Northern Hemisphere. Arctic air rushed into both North America and Eurasia, and, of course, it was replaced in the polar region by air from middle latitudes. The degree to which Arctic air penetrates into middle latitudes is related to the Arctic Oscillation (AO) index, which is defined by surface atmospheric pressure patterns and is plotted in Figure 6. When the AO index is positive surface pressure is high low in the polar region. This helps the middle latitude jet stream to blow strongly and consistently from west to east, thus keeping cold Arctic air locked in the polar region. When the AO index is negative there tends to be low high pressure in the polar region, weaker zonal winds, and greater movement of frigid polar air into middle latitudes.

Figure 6 shows that December 2009 was the most extreme negative Arctic Oscillation since the 1970s. Although there were ten cases between the early 1960s and mid 1980s with an AO index more extreme than ‐2.5, there were no such extreme cases since then until last month. It is no wonder that the public has become accustomed to the absence of extreme blasts of cold air.

Figure 7. Temperature anomaly from GISS analysis and AO index from NOAA National Weather Service Climate Prediction Center. United States mean refers to the 48 contiguous states.

Figure 7 shows the AO index with greater temporal resolution for two 5‐year periods. It is obvious that there is a high degree of correlation of the AO index with temperature in the United States, with any possible lag between index and temperature anomaly less than the monthly temporal resolution. Large negative anomalies, when they occur, are usually in a winter month. Note that the January 1977 temperature anomaly, mainly located in the Eastern United States, was considerably stronger than the December 2009 anomaly. [There is nothing magic about a 31 day window that coincides with a calendar month, and it could be misleading. It may be more informative to look at a 30‐day running mean and at the Dec‐Jan‐Feb means for the AO index and temperature anomalies.]

The AO index is not so much an explanation for climate anomaly patterns as it is a simple statement of the situation. However, John (Mike) Wallace and colleagues have been able to use the AO description to aid consideration of how the patterns may change as greenhouse gases increase. A number of papers, by Wallace, David Thompson, and others, as well as by Drew Shindell and others at GISS, have pointed out that increasing carbon dioxide causes the stratosphere to cool, in turn causing on average a stronger jet stream and thus a tendency for a more positive Arctic Oscillation. Overall, Figure 6 shows a tendency in the expected sense. The AO is not the only factor that might alter the frequency of Arctic cold air outbreaks. For example, what is the effect of reduced Arctic sea ice on weather patterns? There is not enough empirical evidence since the rapid ice melt of 2007. We conclude only that December 2009 was a highly anomalous month and that its unusual AO can be described as the “cause” of the extreme December weather.

We do not find a basis for expecting frequent repeat occurrences. On the contrary. Figure 6 does show that month‐to‐month fluctuations of the AO are much larger than its long term trend. But temperature change can be caused by greenhouse gases and global warming independent of Arctic Oscillation dynamical effects.

Figure 8. Global maps 4 season temperature anomalies for ~2009. (Note that Dec is December 2008. Base period is 1951‐1980.)

Figure 9. Global maps 4 season temperature anomaly trends for period 1950‐2009.

So let’s look at recent regional temperature anomalies and temperature trends. Figure 8 shows seasonal temperature anomalies for the past year and Figure 9 shows seasonal temperature change since 1950 based on local linear trends. The temperature scales are identical in Figures 8 and 9. The outstanding characteristic in comparing these two figures is that the magnitude of the 60 year change is similar to the magnitude of seasonal anomalies. What this is telling us is that the climate dice are already strongly loaded. The perceptive person who has been around since the 1950s should be able to notice that seasonal mean temperatures are usually greater than they were in the 1950s, although there are still occasional cold seasons.

The magnitude of monthly temperature anomalies is typically 1.5 to 2 times greater than the magnitude of seasonal anomalies. So it is not yet quite so easy to see global warming if one’s figure of merit is monthly mean temperature. And, of course, daily weather fluctuations are much larger than the impact of the global warming trend. The bottom line is this: there is no global cooling trend. For the time being, until humanity brings its greenhouse gas emissions under control, we can expect each decade to be warmer than the preceding one. Weather fluctuations certainly exceed local temperature changes over the past half century. But the perceptive person should be able to see that climate is warming on decadal time scales.

This information needs to be combined with the conclusion that global warming of 1‐2°C has enormous implications for humanity. But that discussion is beyond the scope of this note.

Hansen, J.E., and S. Lebedeff, 1987: Global trends of measured surface air temperature. J. Geophys. Res., 92, 13345‐13372.
Hansen, J., R. Ruedy, J. Glascoe, and Mki. Sato, 1999: GISS analysis of surface temperature change. J. Geophys. Res., 104, 30997‐31022.
Hansen, J.E., R. Ruedy, Mki. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl, 2001: A closer look at United States and global surface temperature change. J. Geophys. Res., 106, 23947‐23963.
Hansen, J., Mki. Sato, R. Ruedy, K. Lo, D.W. Lea, and M. Medina‐Elizade, 2006: Global temperature change. Proc. Natl. Acad. Sci., 103, 14288‐14293.

932 Responses to “2009 temperatures by Jim Hansen”

  1. 151
    Hank Roberts says:

    > Al Fresco
    > an official response

    You’re asking about misinformation in the press
    You want to dignify bad work by a poor writer by an “official response”?
    What official do you think would appropriately respond to this guy?
    Remember–it’s a British newspaper. They have their own ways of dealing with this stuff.

    I refer you again to the (British) bloger’s response

  2. 152
    Hank Roberts says:

    > Al Fresco
    Did you follow the pointer Stoat gives there?
    What better “official response” could you ask for than this one?

  3. 153

    102 Compfu,

    I was trying to point out the part of the NOAA curve on ocean heat accumulation that seemed to exceed expectation. The huge numbers are owned by NOAA, not me. And yes, they represent all the oceans down to 700 meters. That is a lot, but nowhere near all of it.

    Yes, the oceans have huge heat capacity, and that capacity can moderate atmospheric temperture increases, which is my point.(see #144)

    What is this about not being careful? Maybe rocks should be thrown, but not until you understand my question. If my way of asking the questions has been confusing, I apologize for that, but no apologies are offered for asking questions.

  4. 154
    Paul C says:

    Thank you for the quick response. Unfortunately, the plate caree, nor the Robinson projections are equal area projections, which was the point of my original comment. AN equal area projection temperature plot would likely look very different. Unfortunaltely, I am a casual observer and do not have the expertise to plot it for myself and have to rely on honest interpretation of data from others.

    [Response: I’m not arguing with you, but plate-caree is a common default for lat-lon gridded data in this field and that would take some work to dislodge it. It is not ‘dishonest’ to use it. If you want to play around with the data in different projections, download Panoply and use it to view the data. – gavin]

  5. 155
    Don Shor says:

    117 greg kai says:
    18 January 2010 at 9:04 AM

    This is true that gardeners have been able to grow less and less hardy variety in Europe and US those last years. However, those last 2 winters, many of those “exotics” growing north of their recommended regions have died, except if the gardeners have been very carefull protecting them effectively. Many species are more sensitive to the lowest temperature than the average, and a few mild winters can gives false impressions, makeing gardeners overenthusiastic and real sad when a hard winter hit after their precious tree has thrived for a few years. I know it, here in Belgium i am not sure my bamboo will make it through this winter (last one was too hard), and I know some people crying over dead olive trees (they have been really optimistic)…

    So I think that southern species extending their habitat to the north is a good indicator of a warming climate, but only after a few years or dozen of years, you need time to catch low probability hard winters that really limit a species expansion. In this respect it is not really better than 10 years temperature averages…

    It is difficult to make any reasonable assessment of climate change based on anecdotes from gardeners, because what gardeners are growing is not consistent over the decades. There are many horticultural varieties, varying in cold hardiness and vigor (a factor in recovery from freeze damage). For example, there are plenty of bamboos that are hardy in Belgium, some of which were not likely available in the nursery trade 30 years ago. You can probably grow species and varieties of Fargesia and Phyllostachys. Citrus hardiness varies by rootstock, and clones probably differ as well (there are at least four different strains of “Satsuma” mandarins on the market).

    And it only takes one single cold episode to wipe out several years worth of mild winters’ growth of exotics. In the years I’ve been in the nursery business we’ve had four major freeze events in Northern California: 1975, 1990, 1998, 2007. Some of those killed plants that had been established for many years. Of course, people promptly replanted them….gardeners always try to grow things that are out of their range.

    Having said all that, the USDA has revised its hardiness zones to reflect longterm trends:
    And here’s a cool interactive map from Oregon State University:

    Changes in populations of native plants might be a better guide to local climate change.

  6. 156
    Don Shor says:

    101 Barton Paul Levenson says:
    18 January 2010 at 4:43 AM

    Don Shor,
    You need 30 years to tell a climate trend. 10 years tells you nothing at all.
    Temperature has risen strongly over the past 30 years.

    Right. 1/3 of the period is irrelevant. Got it.

  7. 157
    Hank Roberts says:

    > Don Shor …
    > irrelevant. Got it.

    Don, you didn’t get it.
    For that data set, 10 years is not “irrelevant” — it’s inadequate.

    Want to learn why?

    “Now, if you trust me absolutely (which I don’t recommend — and if I’m talking science, you don’t need to), you can stop and move on to some other reading. But let’s take a look at the whys. As before, I’m putting the data and programs on my personal web site and you can run the analysis yourself, and modify the programs to work on different assumptions, methods, data sets.

    Let’s consider the first point — how long it takes to determine a climate trend in global mean temperature….”


  8. 158
    Radge Havers says:


    Sorry. No offense intended. This is about as calm as I get.

    Maybe I should switch to decaf.

  9. 159
    Paul Levy says:

    To Gilles #148 – I lived in Switzerland for 3 years, and people there are already well aware that compared to decades past, it snows less in winter, and is much hotter in summer. (I think I remember reading that warming has occurred faster around Lac Leman than any other area of Europe.) Glaciers all throughout the Alps are retreating. What does that mean for you? Well, if you like your skiing then you’ll have to go higher, and consequently pay more, and probably be more limited in what times of year you can do that. Areas not so far from you will be prone to flooding; natural water sources will diminish. The only people benefitting from this will be the air conditioning industry, rushing to install in buildings that were built for a cooler climate. This, in fact, is more or less the description of what has already happened. You can judge for yourself what will happen in the future.

    All of this is very well known to people living in the Swiss Alps – I doubt the French Alps are quite so different.

  10. 160
    Ray Ladbury says:

    Don Shor, Ever hear of Yasuyuki Aono? He conducted some rather amazing work correlating temperature to opening times of Cherry blossoms in Kyoto. It indicates about a 2-2.5 degree rise in temperature over the last century. You can find it described here.

  11. 161
    Don Shor says:

    One of the only redeeming features of the article linked earlier in this thread….

    … is that it apparently features direct quotes from Drs. Latif and Tsonis. Most others that I’ve seen paraphrase Dr. Latif and distort his meaning.

    Dr. Latif:
    ‘A significant share of the warming we saw from 1980 to 2000 and at earlier periods in the 20th Century was due to these cycles – perhaps as much as 50 per cent.
    ‘They have now gone into reverse, so winters like this one will become much more likely. Summers will also probably be cooler, and all this may well last two decades or longer.
    ‘The extreme retreats that we have seen in glaciers and sea ice will come to a halt. For the time being, global warming has paused, and there may well be some cooling.’

    Prof. Tsonis, head of the University of Wisconsin Atmospheric Sciences Group, referring to MDO’s:

    ‘They amount to massive rearrangements in the dominant patterns of the weather,’ he said yesterday, ‘and their shifts explain all the major changes in world temperatures during the 20th and 21st Centuries.
    ‘We have such a change now and can therefore expect 20 or 30 years of cooler temperatures.’

    Assuming they were accurately quoted (I realize that is a big assumption!), it seems that they
    1. consider the trend of the last decade to be significant.
    2. possibly have an explanation for why global temperatures have been rising at the lower end of the models.

    Note that they are not saying “global warming has stopped.” But Dr. Latif himself used (we assume, since it is in quotes) the term “paused.”

    So apparently Dr. Latif and Dr. Tsonis don’t believe that “10 years tells you nothing at all.”

    In response to denialists who cite MDO’s via Latif and Tsonis, it should be pointed out that any conclusions from their data also suggest that warming would likely resume in a couple of decades when the pattern reverses.

  12. 162
    KTB says:

    Does anybody have an explanation why the GISS data keeps changing all the time?

    Article about it (but other people have noted this as well, so the changing is real).

    What does this mean?
    The data in question:

    Is there some summary somewhere about the changes, and are the changes always/mostly in a warming direction?

    [Response: This is very confused. GISTEMP is an analysis of the raw data and homogenisations provided by GHCN and others. Over time, the homogenisation and corrections have changed at GHCN (and USHCN) and GISTEMP has incorporated those corrections (this is the biggest difference between the 1999 and 2001 analyses (as can be read in the documentation i..e Hansen et al (2001)). For time periods near the present, new data is added to the database, sometimes up to 2 years late. The analysis will obvious adjust to include that. Additionally, GISTEMP makes an urban correction based on how nearby rural sites are warming. This uses a two-piece linear fit and uses all the data to make that fit. Given longer time series, the fits will change a little and so therefore will the urban correction. All the code is available here if you want to see for yourself.

  13. 163
    Ray Ladbury says:

    Gilles @148, so where does your water come from? If from glacial melt or snowpack, you will likely have an issue? Your food? I presume you do not grow your own food. It may well be that they may no longer be able to grow winter wheat in France–a tragedy, in my opinion, as the French have turned baking into alchemy. This will of course affect livestock, etc. Given likely degradation of coral reefs and other resources critical to fisheries, you can expect less food from the sea.

    Do you perhaps have a spare room in which you could put up a distant cousin whose house is inundated in periodic coastal flooding? And of course, it will be difficult to stop immigration from areas more severely affected than yours–people will have to resettle somewhere.

    That is a beginning.

  14. 164
    Doug Bostrom says:

    Al Fresco says: 18 January 2010 at 12:58 PM

    “My reason for thinking a more comprehensive response to the Smith/D’Aleo article would be useful is based on the predictable use of that article by the deniers to summarily discount any findings based on NASA data.”

    [bold mine]

    Me, too. It’s pretty obvious (and you can see it from various Telegraph/Mail/Mirror articles being flung into this thread) that the “scientists are corrupt, data is bad” concept is where doubters are pinning their hopes these days, and no wonder because it’s both a wise move and the only solid card they’ve got left. Everything else lacks power and is incoherent, but this is completely irrational and thus potentially very dangerous.

    All of these “silly rumors” need to be jumped on with both feet, with succinct and cogent responses backup up with some form of appendices. Immediately! If there’s one thing we know about PR, time is of the essence. You don’t let trash talk from your opposition fester, you pick it up and deal with it pronto.

    Look, at this point the “science is settled” enough to conclude this entire problem needs to be transferred to the public policy arena for swift action. It’s a social science and political problem now, and that moves it solidly into the realm of perceptions as opposed to depending on facts.

    Ask John Kerry how much good his solid service track record did him. Unimpeachable, wasn’t it? Uh-huh. Now consider that we -know- the same fellow that trashed Kerry’s reputation with fiction is working this case.

  15. 165
    Doug Bostrom says:

    “All of these “silly rumors” need to be jumped on with both feet, with succinct and cogent responses backup up with some form of appendices.”

    And not buried in a thread as a comment, either, I’ll add.

  16. 166
    sam says:

    [edit – no need to copy the whole conversation]

    Ok about the photos…. I have seen the ones in the first link before and remember laughing about it. Were both pictures even taken during the same time of year? What are the dates? I’m sure this could be figured out by looking at the shadows, but not worth it, its only one glacier. Who says that individually their size (or existence) isn’t highly transient? If as you are asserting global warming is causing these glaciers to melt at a much higher rate, wouldn’t there necessarily be a drastic increase in water flowing to the rivers of India? (Conservation of matter anyone?) The other option is that precipitation is decreasing, which is as far as I know not consistent with global warming. [edit]

    About the article you link to…. seems like they [edit] mixed different types of data…. Not worth the paper it isn’t written on.

    [Response: Ah. And you would be the expert on that I suppose. You are exhibiting some confusion though. As the glaciers recede, you will get more water in the rivers initially, but if the snow pack reduces a lot, you end up with more winter flow and less summer flow (assuming constant precip), and that is the major concern. There are other issues related to pro-glacial lakes which can form as the glacier recede, that prone to catastrophic collapse. In the photos, you need to focus on the glacial ice, not the snow cover. – gavin]

    This is the Indian report I read:

    “Vijay Kumar Raina, the geologist who authored the report, admitted that some “Himalayan glaciers are retreating. But it is nothing out of the ordinary. Nothing to suggest as some have said that they will disappear.”

    [Response: That’s a weird statement. But even he shows that the glaciers are retreating, thus this point is uncontested. – gavin]

  17. 167
    Hank Roberts says:

    Don Shor, you repost a link to the Daily Mail article, talking about it including what appear to be quotations — but we know those are misleading.

    Look at the interviews that debunk that article instead, for real quotes:

    When you write
    > don’t believe that “10 years tells you nothing at all.”
    you leave off the important point — which data set does that refer to?

    Annual global temperature data have a known variability that tells us how long a span you need to detect a trend with other data sets.

    Other data sets each have their own variability. Then to figure out how many observations are needed to analyze those, you do the arithmetic:

    This isn’t hard — but it is basic Statistics 101 stuff.

    Statistics 101 is just the basics — my teacher said the goal was to convince us we should talk to a statistician before collecting data, nothing more. Working out how much you need to estimate anything is a significant exercise, for each data set, there’s no single rule of thumb.

    For weather, you can collect data every day. For ocean temperatures, you can collect every day from thousands of different instruments. The variability in each case determines the test needed to have a good chance of knowing for sure that there is or is not a trend.

    For annual global temperatures, you get one number per year, and need twenty or thirty years to detect a trend.

    It’s a new area of mathematics, being developed constantly.

    You’re beating a stuffed animal here, leaving out what you and others need to actually understand what they’re saying.

    Look at the real interview:

    That article ends with:

    The recent articles are not the first to misrepresent his research, Latif said. “There are numerous newspapers, radio stations and television channels all trying to get our attention. Some overstate and some want to downplay the problem as a way to get that attention,” he said. “We are trying to discuss in the media a highly complex issue. Nobody would discuss the problem of [Einstein’s theory of] relativity in the media. But because we all experience the weather, we all believe that we can assess the global warming problem.”

  18. 168
    Doug Bostrom says:

    May I point out again, Don Shor appears to be highlighting a presentation problem, a nit for doubters to pick.

    Can anybody suggest a communications technique that addresses the issue he points out, as opposed to monotonously repeating what we all know but cannot necessarily express in a way that is hermetic?

  19. 169
    Completely Fed Up says:

    Don falls down: “Note that they are not saying “global warming has stopped.” But Dr. Latif himself used (we assume, since it is in quotes) the term “paused.”

    So apparently Dr. Latif and Dr. Tsonis don’t believe that “10 years tells you nothing at all.” ”

    They are SPECIFICALLY saying it doesn’t tell you anything: that is why, though they continue to state and affirm that it’s warming, that a 10year slowdown in warming is still completely valid and doesn’t prove the science is wrong.

    If a 10 year period could tell you something, then they would be saying that seeing a 10-year hiatus in warming would show that the models and the science was incomplete and to such an extend that they are wrong.

    They state the opposite.

    Therefore they are stating that 10 years cannot tell you anything about the climate.

  20. 170
    Completely Fed Up says:

    Jim Bullis: “The huge numbers are owned by NOAA, not me.”

    But using them out of context is your fault, Jim.

    And your attempts to use them in different threads to continue your crusade against a simple but illustrative picture is likewise your fault.

  21. 171
    Richard Palm says:

    I have to wonder what would be revealed if some of the major denialist organizations’ emails were hacked. I know that working climate scientists don’t have time for that kind of thing, but there are a lot of hackers in the world.

    At the very least, one can ask if the denier organizations would be willing to make all their own emails public, and if not, why not?

  22. 172
    Doug Bostrom says:

    Completely Fed Up says: 18 January 2010 at 4:00 PM

    Jim Bullis: “The huge numbers are owned by NOAA, not me.”

    But using them out of context is your fault, Jim.

    Unless I’m reading him wrong, Jim Bullis is trying to point out that increased retention of heat by the Earth is inadvertently being minimized in communications because surface temperature reporting is being dominated by air temperature measurements?

    It’s a communications problem, again. Not an issue with science, as I read it, anyway. Jim Bullis, can you confirm my perception?

    On a related note, I’m going to head off to the Web-0-Sphere and see what I can discover about what we can expect in the way of the ocean burping out heat from time to time, as opposed to absorbing it obediently and smoothly. I have to wonder how much of a contribution to variability this is.

  23. 173
  24. 174
    Completely Fed Up says:

    “It’s a communications problem, again. Not an issue with science, as I read it, anyway. Jim Bullis, can you confirm my perception?”

    If that’s it, then I have got it wrong.

    But I still don’t like it when someone pops along with an argument, gives a stupid number (like, say power integrals over 20 years. Like Whiskey Tango Foxtrot!!!) then when called on it goes “Hey, it’s not my number, it’s $SOMEONE_ELSE’s!”. If it’s someone elses, then why the he** did you bring it up as your endpoint argument?

    It’s VERY easy for someone trying to throw muck in the well to misuse figures from another source then go “It’s not MY numbers!!”.

    It’s happened before: someone used numbers from all over the place and abused them until they said that CO2 from human sources was 0.000012% of the atmosphere.

    When called on it, it was “Those are Wikipedia’s numbers, so go talk to them”.

    But they weren’t. Or at least they’d taken the numbers Wikipedia had on total CO2, human additions and the total CO2 concentration then used those numbers to arrive at that ridiculous endpoint.

    Wikipedia’s numbers, but their own conclusion and argument.

    And Jim’s doing it here, it seems.

  25. 175
    Completely Fed Up says:

    “Can anybody suggest a communications technique that addresses the issue he points out”

    Unfortunately you can’t slap someone with a clue-by-four until either

    a) they stop abusing that fine instrument the human brain (‘cos it’s broken)
    b) the clue actually sticks

  26. 176
    Septic Matthew says:

    159, Paul Levy: Glaciers all throughout the Alps are retreating. What does that mean for you?

    Alpine glaciers retreated in the 1930s, and then they advanced again. Records in the Himalayas are not complete back to the 1930s, so we do not know whether any of them retreated and then grew back.

    [Response: But there are photos from the 1920s showing more ice than now. – gavin]

  27. 177
    Don Shor says:

    “Can anybody suggest a communications technique that addresses the issue he points out”
    Dr. Latif could choose his words more carefully when he speaks to the media. If you go back to the original letter to Nature (Nature 453, 84-88 1 May 2008), they say:
    “Our results suggest that global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming.”

    Maybe he should have left it at that.

    169 Completely Fed Up says:
    “If a 10 year period could tell you something, then they would be saying that seeing a 10-year hiatus in warming would show that the models and the science was incomplete and to such an extend that they are wrong.”

    I don’t see how you leap to that conclusion of what they “would be saying.” The Nature article discusses how, using sea-surface temperatures, they were able to do retrospective decadal predictions. Changes in the MDO’s seem to correspond to variations in measured global temperatures. A 10-year hiatus in warming would lend support to this component of existing models.

  28. 178
    Bill H says:

    Of course the cold waether doesn’t demonstrate the climate is cooling. However, the warmist would have a little more credibility on these issues if they would speak up when warm weather is used to demonstrate that the climate is warming. When that happens Climate warmist are either silent or they are all too happy to join in.

    [Response: Not true. Find one comment by a scientist on this site that demonstrates inconsistency on these kinds of issues. – gavin]

  29. 179
    Don Shor says:

    Glacier photos, past and present:

  30. 180
    Matthew L. says:

    #109 Brian,
    sorry this comment is just non-scientific. The fact that a plant you thought was not hardy actually turns out to be means absolutely nothing. The last two winters have been perishing cold, and a few winters before that rather warmer. That just tells you about some changeability in our local regional climate. It tells you absolutely nothing about global warming.

    If I want to know how temperatures have changed in the UK I will look at the Hadley Central England Air Temperature series (from 1659 to today).

    The average winter temperature (DJF) since 1660 is 3.73c. I have plotted the 30 year rolling mean variance from this.

    Between 1925 and 1940 the 30 year average variance hovered between about +0.65 to +0.75c. After 1940 it dropped sharply back so that average variance for the 30 years to 1969 was -0.01c. It has risen since then reaching +0.89 in 2009. If this winter continues to be cold it is likely this will drop back down to around +0.85 (or lower) for 2010.

    Using the 30 year rolling mean, winters in central England have warmed by about +1.5c since 1660. But there was 1.30c of warming between 1660 and 1925 meaning only +0.2 of net warming in winter has occurred since 1925.

    All interesting regional stuff, but very little proof of global anything except that your recollection of temperatures probably only extends back to the mid 1960s. If it had extended back to the 1930s you would probably think that things had not changed very much, and may even be lamenting how your Palm trees and Rhododendron Falconeri var. Eximium planted in 1925 were killed off by the cold winters of the 1950s.

  31. 181
    David B. Benson says:

    Septic Matthew (176) — Seems you were attempting to change the subject. Do note just how far the Alps have retreated:
    Further than at any time in the past 5200+ years. What does that suggest?

  32. 182
    Lynn Vincentnathan says:

    RE #143, Sam, here are some other peer-reviwed sources re Himalayan glacier retreat & its impact re freshwater resources; we’re talking about 40% of India and 40% of China eventually without water for drinking, much less irrigation and crops, which is an extremely serious situation, not to be taken lightly or mocked:

    (1) Kehrwald, N. M., L. G. Thompson, Y. Tandong, E. Mosley-Thompson, U. Schotterer, V. Alfimov, J. Beer, J. Eikenberg, and M. E. Davis. 2008. “Mass Loss on Himalayan Glacier Endangers Water Resources.” Geophysical Research Letters 35: L22503.

    (2) Kundzewicz, Z. W., L. J. Mata, N. W. Arnell, P. Döll, B. Jimenez, K. Miller, T. Okt, Z. Sen, and I. Shiklomanov. 2008. “The Implications of Projected Climate Change for Freshwater Resources and their Management.” Hydrological Sciences 53.1: 3-10.

  33. 183
    Paul Klemencic says:

    Some of the skeptical camp are trying to come up with an explanation, of why the January satellite data seem to be trending toward the highest January UAH anomaly in the database. The explanation some suggest is unusually large snowfalls in the NH. (see Climate Progress post for links).

    I am interested in the projection that the January ‘10 UAH anomaly will exceed 0.70. I checked the UAH data, and this would be the highest Jan anomaly in the data, beating 0.59 in Jan 07 and 0.58 in Jan 98.

    In addition, the UAH anomaly hit 0.50 last November, the highest Nov anomaly in the records. The runner-up was Nov ‘05 with 0.40 and only two other Nov anomalies exceeded 0.30.

    And the September UAH anomaly hit 0.42, the second highest for that month. The record was Sep ‘98 with 0.43, and only other September reading to exceed 0.30 was Sep ‘05 with 0.35.

    And the July UAH anomaly was also 0.42, the second highest in the record. The record was Jul ‘98 with 0.52, with the third place going to Jul ‘05 with 0.33. Only one other July exceeded 0.30.

    Notice that the other years were El Nino years following a January El Nino peak, and 2010 will be the El Nino year, following this January El Nino peak. The UAH satellite data seem more sensitive to the ENSO cycle than other temperature records, and this could mean 2010 will be a barnburner year for the UAH data.

    1. Is there a reason why the satellite microwave data would show higher anomalies during El Nino years?

    2. Is this a measurement issue, or a definite change in the atmospheric temperatures during ENSOs? I am aware that several people have pointed out a seasonal drop in UAH anomalies from Jan/Feb until May (May has unusually low UAH anomalies).

    3. Can a statistical method be used to take outlier data points that correspond to El Nino years, and use this to ‘forecast’ UAH anomaly data during an El Nino year? It seems more than coincidental that the highest UAH monthly anomalies were dominated by 1998 and 2005, until 2009 second half run-up.

    4. Can we forecast that 2010 UAH anomalies should show a monthly average exceeding 0.40 for the first six months of 2010, with a significant chance that the anomaly could exceed 0.50, and a reasonable chance the anomaly could average over 0.60? Please note that the only time the rolling six month average exceeded 0.60 was in 1998.

    Thanks to any responders.

  34. 184

    “”Please, could you please help me and indicate the proportion of areas on the Earth on which GW will worsen significantly the life condition? (and incidentally why it would worsen exactly?)

    and please also could you give an estimate of the average distance I have to travel to reach the closest region where the conditions won’t worsen significantly ?

    I need to plan my future next decades, say.””

    Hummph. That is a really, really loaded question isn’t it?

    You need to read the peer reviewed IPCC documents which do peer review of the peer review and are unanimously approved by all 130 countries (links below).

    The short term answer is that mainstream science does not have enough confidence in most inhabited areas yet to make confident projections. However some areas will probably see more changes than others.

    Since you asked, you had better read the IPCC documents. However, you asked a pretty specific question which mainstream science is not ready to answer yet (quite rightly).

    So, here are my personal opinions after having been at a national climate research center for 11 years. To me the following seems possible which could affect your question of what areas might be most affected by human-caused climate change.

    I suggest that the inhabited areas being affected now (and will probably continue to be affected), is the American Southwest (including parts of California) and southern Europe. High pressure areas are in general moving in and rain bands are moving away toward the poles at a relatively fast rate (we also detect this in past records of past slowly (relatively) warming natural climates.

    Unless we act soon, economically, I suggest it could be too late and much too expensive and politically prohibitive to transport water in from the Great Lakes, Canada or coastal desalinization plants to stop severe problems in the American Southwestern cities and many parts of California. Mass human migration out of the American Southwest is possible with entire cities being at risk as water simply evaporates. About 75% of the US west’s water comes from snow melt. As the storm tracks move northward and warmer temperatures strike the higher elevations, America’s western water supply will most likely evaporate.

    In the journals, they basically state these areas will probably have water shortages and a reasonably high chance of long term drought.

    I suggest a climate refugee problem from South and East (Caribbean) of the United States’ boarders are possible unless quick and sufficient action is taken to slow human-caused climate change down. With the rain bands moving and sea levels rising, it will probably severely affect many parts of central and south America. This might lead to external immigration pressures on the United States of perhaps up to 100 million or more external climate refugees crowding a possible boarder wall with breaches being most likely.

    I suggest that this could lead to insurmountable infrastructure problems in the United States and a commiserate decrease standard of living in many parts of the USA as food, medical, law enforcement transportation and social networks are quickly pushed beyond their limits.

    I suggest that for many American coastal cities…a high probability of eventually being evacuated unless strong action is taken to slow down climate change. Seas rise for two reasons: thermal expansion and melting ice fields. It is considered prohibitively economically expensive to build protective barriers around all these cities (perhaps maybe some)…many barriers would have to be the same length as the entire US boarder with Mexico.

    I suggest that this could lead to a massive climate refugee problem within the United States much less having severe negative effects to the US economy.

    I suggest an infectious disease problem. Unless sharp action is taken to slow down climate change, with moving rain/snow belts out of productive areas world-wide combined with disappearing glaciers and the elimination of water in most of Asia (melting glaciers mean no river water and that means no irrigation water for most of Asia’s population and rising sea levels forcing the evacuation of most coastal dwellers combined with the loss of reef fishing (“acidifying the oceans”) which many reefs won’t probably be able to tolerate with their associated fishing loss),there will be a huge pressure for a high world-wide death toll perhaps in the billions around the world.

    I suggest that this could lead to unstoppable infectious diseases striking the USA and perhaps the further abandonment of global trade and the evacuation of densely populated areas in the USA. This could weaken the US economy to the extent that any major action to adapt could be severely compromised.

    All these pressures on the USA could lead to intense pressure for many to emigrate to Canada.

    I suggest that northern Europe could be a destination point for 100s of millions of climate refugees from Africa, Asia and Eastern Europe unless sharp action is taken to slow down climate change.

    I suggest that if we don’t take sufficient action, the probable time lines of all these events are uncertain. However, extremely sharp accelerations of climate change have been documented in the far past under natural slow climate change (especially under a possible permafrost sudden release of greenhouse gases).

    Since you asked so where should you move? I think, in my personal opinion, that is a bit drastic to do that yet. I have joked with some people behind the scenes about this. The joking goes that perhaps Canada for its relative isolation and storm tracks moving toward it, the American Great Lakes region for its water, or England for its moat (channel). However, maybe the best place to move, is to stay put and to try to effect action to slow down climate change.

    Remember, the above is not science, but my personal opinion since you asked. The IPCC has very little of this in it, so don’t blame science, blame me. Oh, and make sure to read the IPCC documents below, which is science.

  35. 185
    Lynn Vincentnathan says:

    RE #166, Sam, & “Ok about the photos…. I have seen the ones in the first link before and remember laughing about it.”

    It’s not right to laugh at this tragedy that is unfoldling for India and other countries that get their irrigation and drinking water the Himalayan glacial cycle.

    See my post just above for other sources re glacier retreat.

    I would call on all people to please please reduce your GHGs. Maybe you don’t live in the Himalayan region, but please have compassion for those people who are beginning to suffer increased flooding while the glaciers are melting and will eventually suffer severe lack of water for irrigation in the summer, and rain-fed and melting snow-fed floods in the winter, once the glaciers are gone.

    Please have compassion.

  36. 186

    172 Doug Bostrom,

    That is almost what I am trying to say, but not quite. Surface temperature is a composite of air and water temperature as well as air and land temperature, whatever the basis for surface emissions is.

    I am really talking about the heat that goes deeper into the ocean and thus plays no part in the IR radiation process. I am estimating that the temperature below about 50 meters has no role in IR radiation upwards, and of course the boundary is not an abrupt thing.

    My central point is that the ocean has the capacity to take up a lot of heat and the wind ocean interface has the power to make this happen as a function of increasing temperature. And this process of taking up heat will act to reduce the surface temperature. Thus, even though there is a serious amount of heat being held by the globe, it might not cause surface temperatures to go up all that much.

    170 Comp. F.U.

    If this chart you refer to is a wrong explanation, maybe due to an attempt to simplify, then it needs to be fixed. However, it is you that asserts my purpose as a crusade against that chart. I don’t care that much about it except that it distracts away from what I think is a real discussion.

    I think the threads I am on relate to interpreting the predictions relative to actual measurements.

    Your contention that I am using the NOAA numbers out of context seems to show that you do not understand the difference between heat and temperature, or maybe there is confusion about the difference between the deep ocean and the atmosphere.

  37. 187
    Jerry Steffens says:

    176, Septic Matthew

    Look at the graph of global glacier thickness change here:

    (scroll down to the bottom of the page)

    The graph clearly shows that the total ice volume in mountain glaciers has been steadily declining for the last 50 years.

  38. 188

    #174 Comp.F.U.


    #175 Comp.F.U.


    I am reading points from the NOAA chart on heat content of the ocean and trying to discuss the meaning of them. What is out of context about that?

    Then I make a point that seems to cause you great discomfort.

    Please let me know your technical objections.

  39. 189
    Al Fresco says:

    > Hank Roberts

    I am not talking about the article referring to the work of Latif. I am talking about the article written by Smith and D’Aleo that accuses NASA climate scientists of manipulating data to skew the results in their favor. The latter article is currently spreading like wildfire in the blog-o-sphere. That’s why I think something should be done to deconstruct their argument before it becomes accepted as fact by the public. Failure to respond decisively gives the false impression that the accusations are legitimate. See for the article that is of concern to me.

    Since you ask, I can think of no one better qualified than Jim Hansen to address this issue.

    [Response: But there is no there, there. It’s based on nothing but ignorance as explained previously. – gavin]

  40. 190
    Gilles says:

    Ray, Paul , thank you. Well of course , there are some station resorts at 1500 m or so, that would be sad that they don’t have enough snow anymore, but how to say … most people on the earth don’t have ski resorts AT ALL isn’t it ? furthermore, which cut on fossile use do we have to do to avoid that significantly ? I heard of cutting by a factor 4 .. hemm.. difficult to imagine how people can travel each year through France to go skiing if they have to burn one fourth of the current consumption. Most probably they won’t be ski resorts any more in this case, or restricted to a very small number of people. So If I can’t go at all skiing to keep snow where I won’t be able to go … hmmm.. I wonder also how people from Maldives islands would live without tourism, but it’s their problem.

    Concerning water, well, I’m living under a 3000 m mountain, there is no big glacier, but there is water flowing in rivers the whole year. I assume that’s a kind of big sponge. I can hardly imagine why there wouldn’t be any water raining on these mountains.Doesn’t the water evaporate from the oceans, and with a still higher rate when it’s warmer ? (I heard of some retroaction by water vapor, so I imagine that this water must rain sometime again on the earth). Of course it would be very sad that ALL the water rains on my poor cousins to make floods and so on, but not any more on my mountains to bring me drinking water :( do you really think that this can happen? and to most people on the Earth? I’m scared…)

    But I heard that glaciers have retreated since the mid-XIX century. So may be we still have a chance to survive this, since my grandparents and my parents have survived the diminishing glaciers during their life – actually I can’t remember they ever told me about a shortage of water in France because of that. They told me about two wars, economic crisis, les années folles, de Gaulle, Brigitte Bardot, but I can’t remember they have given a great importance to retreating glaciers. Oh yes, may be, seeing an old postcard of the Mer de Glace, during holydays..

    Speaking of my cousins living near costs (I have some indeed) I read that that IPCC forecasts a sea level rise between 20 cm and 60 cm. None of my cousins lives with the head constantly between 20 cm and 60 cm above sea level, as far as I know. But I will check .You probably know that the tides on the Atlantic coasts have an amplitude of several meters, so I cannot really imagine what a 60 cm rise would exactly do. I think very few people have built their house just 60 cm above the highest tide. Probably some beaches would be narrower, but beaches evolve spontaneously anyway don’t they ? Actually I can’t tell you where the beach was exactly 50 years ago – it seems that nobody really cares, people are so unconscious. Concerning floods, there are some indeed, but they seem to be much more due to urbanization, tarring of surfaces, building in the bed of rivers, and so on, than to temperatures.

    So I’m embarrassed. It is still very difficult to imagine precisely what will happen and where to go.I mean i COULD have been italian or spanish, with a temperature definitely higher than mine. Actually I went in quite a lot of countries with a higher temperature than mine. But I had the impression that the standard of living was much more correlated with the use of fossiles than with the temperature. May be I am wrong? do you have some statistical study that shows that fossile don’t really matter for life , but temperatures do ?

  41. 191
    Hank Roberts says:

    Matthew, please: “we do not know” — unless you have parasites, this is overplurification. You may well not know, but you can look it up. If someone told you that the information isn’t available — who told you that? Why do you rely on that source? Why do you trust your source?

    Do you know how important this glacier is? What river rises from it?

  42. 192
    Mal Adapted says:

    Now here’s a idea for communicating to the public: even cartoon animals get it.

  43. 193
    David B. Benson says:

    Gilles (190) — Learn about storm surge. During Katrina the surge invaded many kilometers inland. That’s at current sea levels, mind you.

  44. 194
    sam says:

    [edit – no need to copy the whole conversation]

    Sure, I concede that it looks like some or maybe even a majority of the glaciers are shrinking. But if I had to place money on it, I bet it will continue to snow in the himalayas for a long long long time and this snow will have to go somewhere. Whether it melts off in 6 months or is buffered in a glacier for 1 thousand years the water still has to go somewhere!

    What I don’t understand is that people on the pro AGW side of this issue will assume that any side effect of predicted global warming are negative. Isn’t it at the simplest (and perhaps most accurate) level just as likely that the side effects might be positive? It’s just a temperature increase, it has no evil, diabolical spirit or intelligence! [edit – OT]

    [Response: You are fighting straw men. Melting glaciers do have impacts for irrigation, summer river flow and the potential formation of unstable proglacial lakes. They are also very clear signs that the planet is indeed warming. But no-one as far as I can tell has ever said this is the worst possible impact of global warming – I would put sea level rise and shifts in the sub-tropical arid zones much higher up in the list. You do touch on a real issue – which is that absent our reliance on the status quo, climate change is neither good nor bad. However, we have built our cities, our agriculture, our infrastructure in the expectation that climate won’t change too much – whether that is a reliance on the statistics of 100-year floods, or the hardiness of plants, or the height of the sea wall, or depth of the sewers, or the availability of irrigation. We, sometimes unconsciously, rely on services that are provided by the climate – by rainfall, by ecosystems, by currents, by winds. All of these things could be changed given enough time, goodwill and money – but don’t underestimate how hard it would be to resettle a big fraction of Bangladesh, or to build a barrage in New York Harbor, or build extra reservoirs to provide the water storage no longer provided by the snow pack. Some adaptations will be easy – the English can grow better grapes, heating costs for the Swedes might decrease – but lots won’t be. And the faster things change, the more costly it will be. NB. Might I suggest if you want to argue here, you confine yourself to criticising things that are said here, and not on the wilder shores of the internet. People looking for stupidity will also find it, but don’t confuse that with reasoned discussion. However, if reasoned discussion is not your goal, you will be happier somewhere else. – gavin]

  45. 195
    Josh Cryer says:

    KTB, I’m writing an article about GISS “raw” data, and about USHCN raw compared to NCDC. I discovered how these data sets are incorporated while looking at D’Aleo’s Central Park allegation (he claims that GISS uses “cooked” GHCN data, while linking homogenized data to “compare”).

    To answer your qusetion (if gaven’s response wasn’t sufficient), GISS uses USHCN (F52 for v2) which changed from v1 to v2. If you actually look at what the homogenization process does, though, you will find that the overall warming trend is decreased with improved methods, not increased as is the allegation on so many denialist websites (the homogenization methods decrease it due to UHI, which is quite visible on many stations). I will show this in due time once I write the software to do the analysis.

    What we usually get with denialists is cherrypicked stations that were originally “cool” but because of TOB (time of observation bias) are made “warm.” Or other station changes which introduce huge anomalies. This scientific analysis of stations is used by denialists to “prove” data cooking.

    The website where I show D’Aleo’s poor data construction methods is in my name, btw.

  46. 196
    Septic Matthew says:

    187, Jerry Stefens,

    Thank you.

  47. 197
    Luke says:

    # 79 Evagrius – Here is your response. Prof Latif was taken out of contect as per usual. Prof Latif did not say what your article is suggesting he did.

  48. 198
    Septic Matthew says:

    176, Gavin: [Response: But there are photos from the 1920s showing more ice than now. – gavin]

    I am pretty sure that my memory of advancing glaciers came from reading the journal Science. I’ll see if I can find the reference.

  49. 199
    Tom S says:

    Regarding the IPCC Glacier Problem. Many people here are missing the point. The issue is how a wildly inaccurate statement which borders on alarmist hysteria made it unchecked into AR4 and stayed there for two years. You can’t both claim the IPCC as a definitive scientific peer reviewed assessment, and then casually dismiss this as a minor overlook.

    [Response: There is a big difference between definitive and infallible. Until last month I’d never heard of this claim – though looking back through google news it has been used, mainly in Indian sources, for a couple of years. Since it’s wrong, it will get fixed (that’s the thing with science, it progresses – even if people make mistakes). But to conclude that every fact in IPCC is now wrong is very dumb. It is still your best bet for what we know – even though that is improving all the time. Given the scrutiny IPCC has had since it was published, the infrequency of problems with the text speaks very well for it’s peer review quality. – gavin]

    Check Google for how many times this and the consequences has been repeated without ANYONE ever checking until now. Here is the original CNN article:

    This lessens credibility further. Are there more landmines in AR4? Maybe someone should suggest double checking this? This debate is not a fair fight, and it shouldn’t be. AGW proponents are asking for great public resources to solve a theoretical future problem that has significant uncertainties (which are frequently understated IMO). Public perception matters if you want their money.

  50. 200
    Septic Matthew says:

    177, Don Shor: Dr. Latif could choose his words more carefully when he speaks to the media. If you go back to the original letter to Nature (Nature 453, 84-88 1 May 2008), they say:
    “Our results suggest that global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming.”

    Dr Latif, I believe, invites misquotation: you can’t tell from this quote whether he thinks his model does or does not predict non-warming for the “next decade”. You can’t tell from some of his more recent quotes whether he does or does not believe that it is fair to characterize the 1999-2009 decade as a decade of non-warming.