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.
References:
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.
RS: Mann’s hockey stick paper was considered good enough to be published in Nature. Yet it is still controversial.
BPL: Not to climatologists, it isn’t. Just to internet crackpots.
Jacob Mack: it is foolish for some to think global warming is the worse issue we face as the human race.
BPL: Does the phrase “complete collapse of world agricultural production” mean anything to you?
John Storer, I rather doubt that. What error model are you assuming? It can’t be a 4 parameter model, because your error model must also have parameters. What is more, the date the change occurs is a parameter as well.
Toledo Tim doesn’t understand the rules of the game. What keeps anthropogenic causation at the top of the hill is the fact that the science supports it. Go learn the rules (science), then come back.
JS 635,
I still suggest you do a partial F-test on your CO2^2 term. If you want to forward me your data I’ll do it for you. Would that be easy?
Toledo Tim,
Yeah it is really malicious (the word is not “malace”) to tell pseudoscientists they have it wrong. We ought to give equal time to creationists and biologists, Velikovsky freaks and astronomers, Nibiru cultists and archaeologists, and of course, OF COURSE, AGW theory deniers with climate scientists. All opinions are equally good and ought to be treated with equal respect!
Why do you have to manipulate the raw measurements, can you not use stations that are not subject to urban encroachment and plot the raw figures ?
[Response: The weather station network was not designed with climate in mind, and changes in instrumentation, location, altitude, time of observation etc. introduced inhomogeneities into the records that need to be dealt with before you can get at the climate signal. – gavin]
Doug Bostrom @ 625:
Yes and no. I’m also concerned that complex methods are being relied on to “fill-in-the-blanks” without on-the-ground verification via the old tried-and-true “read a thermometer” method.
On the perception side, deople are being asked to radically alter their entire lifestyle and someone in the Canadian government can’t be bothered to get weather data reported. WTF?
Lynn, should a few degrees of temperature increase cause such a dramatic reduction in corn production one has to wonder why nations such as Mexico and Egypt even bother planting any much less why their corn production has also increased significantly (in the common meaning of the word) over the last 50 years. Perhaps they use different hybrids? Adjust their growing seasons accordingly? It does not seem to be an insurmountable problem.
By the way Ray. Why the fascination with Methane? It is short lived in the atmosphere (5-15 years) and it’s oxidation byproducts are water vapour and CH3.
the CH3 is further oxidised to CH3O2 which reacts with the peroxy radical HO2 to produce methyl hydroperoxide and oxygen. The hydroperoxide is then precipitated out of the atmosphere in rainfall.
The OH radical is not limiting. CO2 is NOT an oxidative byproduct of methane oxidation.
The short residence time of methane along with it’s precipitation out of the atomsphere relatively quickly through it’s oxidation byproducts make it a non-event unless there is a massive release of methane to the atmosphere and there is no evidence of that at this time.
Source: Wayne, R.P. (1992)Chemistry of Atmospheres (second ed.). Oxford Science Publications. 447pp. Oxford University Press.
Re: #631 (arch stanton),
Arch,
I well remember my final few attempts at dialog here. I was well aware, probably in early 2008, that the solutions business, always on thin ice, had become a fraud. I saw my own beloved Dr. Hansen go from telling us that atmospheric CO2 stays aloft “essentially forever” to telling us that not only did we need to get back to 350 ppm to avoid +2*C of warming, but that it was actually possible to do as long as we stop burning coal immediately.
(a) That was a lie if his first statement was true.
(b) Sheer inertia means we will certainly exceed 450 ppm and perhaps go much higher than that;
(c) There was never the slightest chance that the world would stop burning coal in anything close to the timetable that Dr. Hansen insisted we needed.
I saw scientists go from impartial people doing work to advocates of hardened positions. And worse, those hardened positions were impossible to achieve. And still worse, being too rigid makes something more breakable, and climate science is becoming too easy to break because it won’t bend.
And finally, the human race has made its choice. It prefers abundant energy today instead of worrying about the future. “Central planning” would require an enormously heavy governmental hand, which free people flatly reject.
In other words, we’re going where we’re going no matter what anybody says, and so there are two paths, neither of which gets any traction at RC:
(1) Adaptation. The world will warm past +2*C, lots of permanent ice will melt (perhaps the vast majority of it, perhaps within the next several hundred years); world sea levels will rise a lot (perhaps half a meter in this century, perhaps more than that) and we will be forced to make survival choices. This is inevitable.
(2) Geoengineering. It will become necessary to find ways to remove carbon from the atmosphere. Period. Nobody wants to admit it, but there is simply no avoiding it. Especially given the scenarios that Dr. Hansen espouses.
So, while I respect the “more to learn” attitude, there is nothing more to learn about AGW that will save us from the above. It’s time to think clearly about what comes next, not argue back and forth for 14 pages over whose measurements and methods to trust.
The world is a red map, year after year. The planet is warming. We did it.
Now we get to deal with the aftermath. That discussion will not take place here.
Completely Fed Up #644
“But denialists will not let the idea go that such CO2 has no role.”
Completely, why keep trotting out these phoney straw men. The skeptics position is that the IPCC climate sensitivity numbers are too high – not that CO2 has no role. The skeptics position is that CO2 is not a pollutant. The skeptics position is that there is no climate emergency. Let’s at least be honest about where the argument is.
“But farmers aren’t going to sit by and wring their hands while yields decline. Agribusiness will develop more heat-tolerant varieties, and growers will choose other things to grow.” – Don Shor
It’s true that farmers are adaptable; but they can’t work magic; nor can agribusiness. I attended a talk on crop production and food security by Prof. Peter Gregory, a recognised expert in the area, last week. He noted that yield/hectare increases for one of the world’s three main crops – rice – have already slowed, and those for wheat and corn appear to be following the same sigmoid curve. Also that agricultural experts consider “peak phosphorus” a more urgent problem than “peak oil”. Third, that gains in yield due to longer growing season tend to be greatly reduced in the field, because the longer growing season also helps pests. Fourth, that the continuing trend toward sowing fewer varieties increases risk.
FCH @ 658 – “People are being asked to radically alter their entire lifestyle” Please explain what you consider radical about people being asked to consider insulating their houses, driving less polluting cars and taking fewer flights… Oh yes, I forgot, it’ll “send us back to the Stone Age…”
I recently read one denialist blog seriously describing a general request to restaurants not to serve iced water as “ORWELLIAN!” “Whatever next, soon they’ll be demanding we walk to the corner shop. Is there no end to their Draconian fascisto-Marxist diktats?!”
“someone in the Canadian government can’t be bothered to get weather data reported.” Again with the alarmist exaggeration.
Gavin:
“This is untrue, defamatory and based on a complete ignorance of both where the data comes from (CLIMAT reports from WMO) and the whole point of the anomaly method.”
Yes, I find the whole argument about moving thermometers from cold mountains to beaches as being rather idiotic. What does concern me, however, is the increasing percentage of thermometers that are at airports; the falling percentage that is rural; and the idea that one rural is as good as another and no adjustment is needed. Rural communities can grow also. And depending where a thermometer is placed within the community it can make a difference.
What also bothers me is this USHCN chart that shows that their adjustments are now adding more than .5C to the raw data.
http://cdiac.ornl.gov/epubs/ndp/ushcn/ts.ushcn_anom25_diffs_urb-raw_pg.gif
And I’m bothered by the fact that GISS takes polar coastal stations that are profoundly effected by local sea ice cover and uses those stations to extrapolate inland where the sea ice effect is less and across the Arctic ocean where the SSTs show that the anomaly is much smaller than what is being extrapolated.
“And I’m bothered by the fact that GISS takes polar coastal stations that are profoundly effected by local sea ice cover and uses those stations to extrapolate inland”
Hadley data doesn’t.
And so a comparison between then should show the effect this problem would have on the result.
And it shows no meaningful difference.
So why are you bothered?
Tilo: ““But denialists will not let the idea go that such CO2 has no role.”
Completely, why keep trotting out these phoney straw men.”
Yeah, I don’t know why they keep trotting out these phoney straw men either. But they do.
Do you know why, tilo?
” Richard Steckis says:
27 January 2010 at 10:01 AM
By the way Ray. Why the fascination with Methane?”
http://en.wikipedia.org/wiki/Methane_clathrate
Would have thought a *scientist* would know more…
Don Shor:
“As it says clearly on page 4, there are many caveats. “The simplest form of adaptation would be to change the locations or seasons where and when the crops are grown.” In other words, farmers aren’t stupid.”
The Canadians may have something to say about US farmers growing wheat on their land.
Russia won’t like India/Pakistan/*stan planting their crops on Russian soil.
Etc.
These sorts of things are how wars start.
And some of us have nuclear weapons.
Walt Bennett,
The only hardened position you will find among the scientists generally is that people accept the science.
But, Walt, part of the science is that there are no validated geo-engineering mitigations at present outside of limiting CO2 emissions. The leading candidates proposed to date–e.g. sulfate aerosols, plankton fertilization…–all have very serious side effects and still have serious doubts about their effectiveness. By all means we should keep looking, but wouldn’t you agree that since we don’t have a strategy in hand now, nor any roadmap to reach such a strategy, it would be irresponsible to proceed at full steam ahead?
FCH: “Okay, so a “limited” number of temperature records doesn’t refute the LIA or MWP being “localized events”, but a “limited” number of temperatures =does= mean that the Arctic is warming?”
Define limited.
The limit in the LIA and MWP is much more limited. After all, we didn’t have a global array of satellites for 30 years in the MWP or LIA…
Steckis asks, “By the way Ray. Why the fascination with Methane? It is short lived in the atmosphere (5-15 years) and it’s oxidation byproducts are water vapour and CH3.”
I’m glad you asked that question, Richard! Although the CH4 has a short residence time, it has much more greenhouse potential than does CO2. Since many of the tipping points in the system are thermally activated, the worry is that a rapid pulse of warming could put us over the top.
Second, we aren’t really dealing with a single pulse, are we? Rather there is a steady and increasing supply to the atmosphere, so the warming would be sustained longer than a decade or two.
Third, a methane pulse is precisely the putative mechanism that initiated the PETM–a period I’d just as soon not repeat.
Fourth, while Methyl hydroxide does precipitate out, it does break down into CO2 and water eventually, and the CO2 does wind up in the atmosphere.
Completely: #666
“And so a comparison between then should show the effect this problem would have on the result.
And it shows no meaningful difference.”
But it does show a meaningful difference.
http://reallyrealclimate.blogspot.com/2008/10/updated-11-year-global-temp-anomoly.html
645: Completely Fed Up says:
27 January 2010 at 4:09 AM
“629
Don Shor says:
26 January 2010 at 3:38 PM
610 Completely Fed Up says:
26 January 2010 at 9:16 AM
How many earthquakes have reduced US wheat production? None. Warming climates have.
Really?”
Really.
Why else would you then quote a report that doesn’t mention earthquake disruption of wheat production and DOES mention how climate has?
Completely Fed Up says:
27 January 2010 at 4:11 AM
Jacob says: “You have not made your case.”
Except even Don Shor has quoted a report that shows the case has been made and has much greater provenance than earthquakes being worse.
That is nonsense. You said climate change has already reduced wheat production. It hasn’t. I wasn’t addressing earthquakes, which don’t affect wheat production. You said climate change has already reduced wheat production. You said it very clearly. It hasn’t. You were wrong. Climate change has NOT already reduced wheat production. You were wrong. Your statement was incorrect. Got it?
669: Completely Fed Up says:
27 January 2010 at 11:55 AM
Don Shor:
“As it says clearly on page 4, there are many caveats. “The simplest form of adaptation would be to change the locations or seasons where and when the crops are grown.” In other words, farmers aren’t stupid.”
The Canadians may have something to say about US farmers growing wheat on their land.
Russia won’t like India/Pakistan/*stan planting their crops on Russian soil.
Etc.
These sorts of things are how wars start.
And some of us have nuclear weapons.
If the price of a commodity goes high enough, arable and that is presently being used for less profitable purposes can be planted. Irrigating land that is presently dryland farmed is another option, if the cost of bringing in water is worth it.
Crop choices can change. Earlier varieties can be planted. With corn, for example, the effect of heat is on the pollen development; there are varieties of corn that tassel earlier in the season. Some farmers will simply shift over to more heat and drought tolerant crops such as safflower.
The comment about phosphorus limitation is actually more relevant than any impact of climate change. Expanded corn production due to the boom in ethanol has already had supply effects on ammo-phos, a staple in the ag and lawn fertilizer industries. There were big spikes in the cost of basic fertilizers over the last couple of years, and those prices tend to trend with oil prices. Federal ethanol policies (and price supports) have much more effect on farmers than a gradual increase in temperatures.
Dr. Gregory has an interesting article “Discernable effects of climate change on crop production” that reviews the impact of climate change over the last 40 years. The URL is long; I’d urge anyone interested to Google it.
Gilles: “If the price of a commodity goes high enough, arable and that is presently being used for less profitable purposes can be planted.”
And all the good land is already planted, Gilles.
“You said climate change has already reduced wheat production. It hasn’t.”
Yes it has.
Your link and quote said so.
More intensive farming increased it too, but without the climate change it would have been even higher.
Don Shor sees no problem with “If the price of a commodity goes high enough”. I do.
“But it does show a meaningful difference.”
No it doesn’t: AGW sensitivity is still on track for a sensitivity of the upper half of 2.5C-4.5C per doubling.
PS 11 years isn’t climate.
Tilo Reber’s link is to an incompetent analysis. Go to http://www.woodfortrees.org/plot/hadcrut3vgl/last:360/trend/plot/gistemp/last:360/trend.
Replace this with an 11-year trend (132 months instead of 360) to reproduce the results in Tilo’s link.
Anybody interested can see that there is negligible difference between HADCRUT3 and GISTEMP slopes.
Don Shor says: 27 January 2010 at 12:58 PM
(and not aimed particularly at you, btw)
May I suggest that choosing a particular crop raised in a particular region and forming conclusions from that is somewhat akin to using local weather for/against the notion of a climate trend?
I found Nick Gotts’ post on this more informative.
https://www.realclimate.org/index.php/archives/2010/01/2009-temperatures-by-jim-hansen/comment-page-14/#comment-157177
In particular the fertilizer issue is of concern. W/regard to discussions on population limits, the “Green Revolution” is frequently cited as a reason for optimism about the planet sustaining a 9GP inventory of people. The green revolution was possible in large part due to fossil fuel inputs; pulling another agricultural production revolution out of our hats is not going to be as easy when we have one arm cut off.
Since my earlier post, I found this excellent publication from Environmental Research Letters that covers many of the topics here and has something for almost every viewpoint:
Global scale climate–crop yield relationships and the impacts of recent warming
David B Lobell and Christopher B Field
It is a pdf with a long URL, so again I’d urge those interested to Google it.
They have constructed a model that attempts to detect yield reductions due to climate change. They show reductions in some crop yields globally, offset to some extent by increased fertilization by CO2. They mention adaptive measures as having possibly countered the impact of temperature. (“Thus, the yield impacts of climate trends reported here can be viewed as the expectation in the absence of explicit recognition of, and adaptation to, climate trends since 1980….these models are limited in their ability to simulate future yield responses when cropping areas shift”). They even showed the impact of sample size (# of years) on results.
“The extent to which farmers adapt to climate trends is thus a source of uncertainty in estimating impacts of past climate change, as it is for projecting future impacts.”
678 t_p_hamilton says:
27 January 2010 at 1:35 PM
Don Shor sees no problem with “If the price of a commodity goes high enough”. I do.
It may or may not be a problem, depending on how we deal with it.
I raise almonds. The price has been pretty consistent, but acreage has been increasing. So as I add more trees on my property, I’m switching to walnuts just to cover my bets. That is my response to price sensitivity, and it is the kind of decision farmers make all the time.
Canning tomatoes used to be a major crop in this area. The price dropped steadily, and many of those fields are now planted in sunflowers (a big improvement aesthetically!) or have been planted in tree crops.
Sugar beets, which were a major crop in our area 25 years ago, are non-existent now due to the gradual removal of price supports. They were often grown on more marginal soils. With some effort at grading and drainage, those could be used for more profitable crops. If not, they will just be used for pasture.
If the price of one commodity goes higher, it will result in more farmers planting it. If the cost of the inputs goes higher, fewer will plant it. Just read any of the farm bureau sites to see how this plays out year to year. It isn’t going to result in mass starvation, as it tends to be self-correcting. But federal price policies have historically been a big factor.
“It may or may not be a problem, depending on how we deal with it.”
Well, by starving people, obviously.
Just because almonds are $600/pound doesn’t mean you’ll be able to grow them in the Gobi Desert.
So how are farmers going to plant more of it?
Who is going to be able to afford it?
Don in post 682: “They show reductions in some crop yields globally”
Don in post 674: “You said climate change has already reduced wheat production. It hasn’t.”
“The green revolution was possible in large part due to fossil fuel inputs; ”
Indeed.
Watch:
http://video.google.co.uk/videoplay?docid=-5267640865741878159#
US output was 2600 calories of food for each calorie of oil used.
Today that figure is 1 to 1.
Has the uptake gone up 2600 times?
The problem with high commodity prices is that it squeezes disposable income, with rather unpleasant effects on the economy. If gas goes up to $5/gallon I guarantee farmers aren’t going to be happy. How are farmers going to deal with it?
People are going to feel the same way about food – if it becomes more expensive because of supply/demand issues.
Ask the western loggers what they think of the spread of the pine bark beetle because of milder winters.
t_p_hamilton: #680
“Tilo Reber’s link is to an incompetent analysis.”
No, tp, your analysis is an incompetent analysis. I’m showing that GISS has diverged since 1998. I don’t care if it didn’t diverge before then. My chart is correct and yours is wrong because it uses the wrong time period.
Even James Hansen recognizes that there is a difference.
Hansen:
“The origin of this contradiction probably lies in part in differences between the GISS and HadCRUT temperature analyses”
Completely: #679
“No it doesn’t: AGW sensitivity is still on track for a sensitivity of the upper half of 2.5C-4.5C per doubling.”
Try to stay on subject Completely, we were talking about GISS divergence, not climate sensitivity.
“Try to stay on subject”
I am.
The subject is “is there a significant difference between HadCRUT and GISS data”.
And there isn’t, they still both track fine.
PS why didn’t you stay on subject? 11 years isn’t climate.
We were talking about climate.
It’s even in the blog name.
“I’m showing that GISS has diverged since 1998.”
Nope, the question is “is there significant divergence”.
You haven’t shown anything of significance because you’ve shown no detailing of the level of significance.
682: Completely Fed Up says:
27 January 2010 at 3:18 PM
Don in post 682: “They show reductions in some crop yields globally”
Don in post 674: “You said climate change has already reduced wheat production. It hasn’t.”
That was my point. The article I cited in 682 plausibly supports both of our positions, depending on the many variables they discuss. You seem to have missed the part about uncertainty and adaptation. Or maybe you didn’t read the article.
Well, by starving people, obviously.
Just because almonds are $600/pound doesn’t mean you’ll be able to grow them in the Gobi Desert.
So how are farmers going to plant more of it?
You missed the point. But never mind.
687 t_p_hamilton says:
27 January 2010 at 3:29 PM
The problem with high commodity prices is that it squeezes disposable income, with rather unpleasant effects on the economy. If gas goes up to $5/gallon I guarantee farmers aren’t going to be happy. How are farmers going to deal with it?
Gas here in California averaged $4.60/gallon in June 2008. Diesel was $5.15/gallon. It affected farmers, truckers, and all of us who are supplied by them. As a retailer I paid more for my goods. Farm operations cost more. We dealt with it by changing behavior.
In fact, rising fuel prices, if sustained, would be a very effective way to change energy use.
May I suggest redirecting followups?
The Tilo Reber Thread : Deltoid
Since Tilo Reber’s comments always seem to take discussion off topic, all further comments from Tilo should be posted to this thread as well as any replies …
http://scienceblogs.com/deltoid/2008/05/the_tilo_reber_thread.php
Tilo doesn’t like being shown incompetent:
t_p_hamilton: #680
“Tilo Reber’s link is to an incompetent analysis.”
No, tp, your analysis is an incompetent analysis. I’m showing that GISS has diverged since 1998. I don’t care if it didn’t diverge before then. My chart is correct and yours is wrong because it uses the wrong time period.”
Your analysis only shows a huge difference because of sensitivity to starting and ending points. That is what is incompetent, arising from not analyzing nearby 11 year periods starting 1 year earlier, or 1 year later. You have discovered noise, and posted it.
“Even James Hansen recognizes that there is a difference.”
Hansen:
“The origin of this contradiction probably lies in part in differences between the GISS and HadCRUT temperature analyses”
Properly done, you can detect a difference in the two trends. It is not nearly as large as the slopes in your plots indicate. For example, the period from 1990 to 2010:
http://www.woodfortrees.org/plot/gistemp/from:1990/to:2010/trend/plot/hadcrut3vgl/from:1990/to:2010/trend
This is because the arctic is heating faster, and GISTEMP has arctic temperatures while HADCRUT3 does not.
672
Ray Ladbury says:
27 January 2010 at 12:20 PM
“Third, a methane pulse is precisely the putative mechanism that initiated the PETM–a period I’d just as soon not repeat.”
Interesting that you use the word putative which means supposed. In other words you are saying that it is not the known mechanism for PETM but a theoretical mechanism.
If a methane pulse is to occur and it will some time in the future, it will not be because of us but will occur through a natural mechanism.
#649, Don, I lived in the Midwest for 25 years. One of the issues there regarding water is the aquifers, such as the great Ogallala Aquifer (see http://en.wikipedia.org/wiki/Ogallala_Aquifer ) are being depleted — not due to GW, but just overuse. Our own local aquifer in Aurora, IL had dropped down 800 ft since water had started being mined from it 100 or so years ago.
Then there is the issue of industrialized agriculture’s heavy dependence on fossil fuels and finite resources, and with “peak oil” there will be “peak food” — see http://peakfood.co.uk/ by a farmer in England — again, not a GW issue.
In Calif, I understand there could be come problem with snowpack river-fed irrigation, as global warming advances and melts snowpacks during winter plus precip coming down as rain, rather than snow. That could mean flooding in the winter, and drought in summer….but I’m not sure when or where in Calif that might happen. It’s similar to the glacial cycle being harmed and disrupted as discussed in this and the later thread.
Then there is toxicity due to CO2 — a little bit more is good for plants, too much becomes bad for various plants…
And there are other issues. More later….
Re: #670
Ray,
You know I value your opinion. I would like to thank you for responding in such a way that I would not feel trampled upon for making this occasional point.
I do appreciate the attempt at actual discussion.
What I’ve said before is that the continued fabrications coming from the “solutions business”, including Copenhagen and whatever comes next, accomplish two things, neither of them useful: (1) They reveal the hardened positions: “Everything’s Melting!” “No it’s not! It’s cold where I live!”; (2) We spend all our time talking about that (see the past 14 pages and any other thread on this site) instead of taking a reality check and asking these questions:
1. What are the likeliest real-world worst case scenarios in the next 25, 50 and 100 years?
2. How much money do we have?
3. What are the various things we need to know more about than we do today?; how quickly can we learn them?; how likely are they to improve conditions in 25, 50 and 100 years?
Now of course we’ve been trying for 20 years to have that conversation; it has not worked. It’s likely not to work. Global solutions to this problem are likely impossible. As we all know, lacking a global solution there is less incentive for ANY country to make sacrifices that are not directly in their own best interest. If the planet will warm ANYWAY because not enough is being done ELSEWHERE, it becomes self-perpetuating that nobody does nearly enough.
That’s today’s reality, and it is 13 O’Clock. It’s past midnight. The horses are out of the barn and so forth. If you follow the actual science and not the rhetoric about the science, and if you ask Dr. Hansen if he meant what he said about CO2 levels being extremely long-lasting, and if you are at all honest about what’s realistic, then you cannot help but come to the conclusion that these are yesterday’s conversations.
So: The above questions must be asked, but at a national level. The U.S. needs to decide how to spend its money, as does China, as does India.
Do you realize that we would ALREADY be above +2*C if we had cleaner air? So as China improves its emissions controls, for example, the problem gets worse. So what’s the correct move?
Ah! Nobody knows. Let’s stop pretending we do.
As to your question: It does not matter, if it ever did, what “we” “should” do, we being the planet and should being what’s best for the planet.
Humans don’t behave that way, and if it was theoretically possible to get them to, you would have to kill a lot of them in order to do it. Forget it, it’s not possible. Just not possible.
I could go on like this all night, write you a 300 page story about my journey these last 3 years since I first endeavored to “dive in” to the climate debate. It isn’t pretty and there is plenty of blame to go around.
If Dr. Hansen, to single out one person, is going to continue to advocate that we can still stay under 2*C if we only do this and that, somebody needs to challenge him to (a) reconcile that with his previous statements and (b) explain how it is remotely feasible to accomplish what he proposes.
How many more years can he keep saying “There’s still time left, but not much?”
My honest belief, based on the science itself, is that the above statement has been a lie for several years.
And so: Mitigation and adaptation, and an investment in a whole generation of new ideas to replace the really lousy ideas we are stuck with at present.
re the opinions about wheat and it’s relation to petroleum and climate change, remember that modern grains require intensive management and certain ecology:
“Farming is the process of ripping that niche open again and again. It is an annual artificial catastrophe, and it requires the equivalent of three or four tons of TNT per acre for a modern American farm. Iowa’s fields require the energy of 4,000 Nagasaki bombs every year. (….) And much of the energy is simply wasted, a trail of dollars billowing from the burglar’s satchel. (….) On average, it takes 5.5 gallons of fossil energy to restore a year’s worth of lost fertility to an acre of eroded land. (….) In 1940 the average farm in the United States produced 2.3 calories of food energy for every calorie of fossil energy it used. By 1974 (the last year in which anyone looked closely at this issue), that ratio was 1:1. And this understates the problem, because at the same time that there is more oil in our food, there is less oil in our oil. A couple of generations ago we spent a lot less energy drilling, pumping, and distributing than we do now. In the 1940s we got about 100 barrels of oil back for every barrel of oil we spent getting it. Today each barrel invested in the process returns only ten”
This is old “news”, but evidently some here haven’t heard it: The conservation of energy is not an option, it is a fact [as PDF
Re my post of 25 January
I revisited the data and found that I used southern hemisphere temperature data rather than global. There is also a collinearity problem with the variable CO2 and CO2 squared which I have sorted using a linear transform. To recant and represent:
Using data for 1958-2008 for temp, CO2, sunspots and vulcanism, global temperature is increasing with increasing CO2, and at an accelerating rate. The recent apparent cooling trend (since 1998) is within the underlying random variation in global temperatures (what I started off looking at).
The data if anyone is interested:
CO2 0.0086 (p=0.000) [An increase of 100 ppm is equivalent to 0.9 degree temp rise and with this increase expected in 70 years]
CO2 squared 0.0000689 (p=0.046)
sunspots 0.000721 (p=0.009)
Volcanic activity -0.0046 (p=0.165)
The 70 years is based on current trends, includes current heat sinks which presumably have limits and does not include anticipation of state changes etc. so it is probably an underestimate. Not sure how this all fits in with people’s hobbyhorses.
cheers
John
PS I am not sure of other people, but I have developed a mistrust of the environmental lobby due to ongoing exaggeration, misrepresentation and catastrophic claims so I don’t accept any claims on face value anymore.
PPS comments about f tests, AIC are understood