Guest post by Steven Goddard
The GISS website shows the graph below, which indicates a steady, steep warming trend over the last 30 years. The monthly average anomaly for 2008 (0.44) is 0.26 degrees warmer than the monthly average anomaly for 1980 (0.18.) Data obtained from here: http://www.woodfortrees.org/data/gistemp/from:1980/plot/uah/from:1980
By contrast, the UAH monthly average anomaly for 2008 (0.05) is 0.04 degrees cooler than the UAH monthly average anomaly for 1980 (0.09.) Again, data obtained from here: http://www.woodfortrees.org/data/uah/from:1980
This 1980-2008 discrepancy between GISS and UAH is important, as it is nearly equal to the claimed warming trend since 1980.
Taking this one step further, I made a graph of the difference between the GISS and UAH monthly anomalies since 1980.
As you can see below, the discrepancy has increased over time. Using Google’s linest() function, the divergence between GISS and UAH is increasing at a rate of 0.32C/century. (GISS uses a different baseline than UAH, but the slope of the difference should be zero, if the data sets correlated properly.) The slope is not zero, which indicates an inconsistency between the data sets.
Click for larger image
Raw data from here: http://www.woodfortrees.org/data/gistemp/from:1980/plot/uah/from:1980 Calculations done here.
Factoring in the baseline
Some readers will undoubtedly again point out that the GISS baseline (“normal”) temperature is lower than the UAH baseline. This is true, but as I said above does not affect the slope calculation. The difference between the GISS and UAH monthly baselines is a constant, which affects the relative position along the y-axis – but it does not affect the slope. Subtracting a monthly constant from each point in a graph does not alter the slope over a large set of years. It only alters the y-offset.
The equation of a line is y = mx + b, where m is the slope and b is the y-offset. m and b are completely independent. The different baselines affect only b, not m. If the UAH and GISS data were closely tracking each other, the slope (m) would be close to zero. The fact that GISS shows 2008 temperatures much higher than 1980, and UAH shows 2008 temperatures lower than 1980, is also a clear indicator that the two data sets are divergent.
Steve McIntyre has coincidentally just done a similar comparison of NOAA USA yearly data vs. GISS USA yearly data, and came to the conclusion that the NOAA slope is even steeper than GISS, diverging from UAH by 0.39C/century.
This would imply that NOAA is diverging from UAH by an even larger amount than GISS is diverging from UAH.
Clearly, problems exist with both datasets.
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DJ, who seems to have his knickers in a twist says:
Aren’t you double dipping there by referring to both “fictional Antarctic data” and “non-existent polar data?”
Also, could you tell us in what way UAH trends fail to obey basic physics and how you think all the things you mentioned bias the data.
DJ,
GISS data is fictional over arctic and antarctic yet that does not stop them from including the polar data in their results.
Has anyone seen David Archibald’s prediction for UAH data through May 2009?
http://icecap.us/images/uploads/oftheMay2009UAHMSUGlobalTemperatureResult12thJanuary2009.pdf
Whoa, he’s really sticking his neck out. It is 180 deg out of phase with Hansen and Met O, and most likely other govt. funded institutions.
DJ,
Thanks for the idea of comparing GISS vs. RSS. I tried the same analysis since 1980, and the divergence was much smaller at 0.02. But the really interesting thing about that comparison is that since the year 2002, GISS has been diverging from RSS at an extremely high rate of 2.6C/century. You can see the graph here.
http://spreadsheets.google.com/pub?key=pj0h2MODqj3jUIR8dYS8TAQ&oid=2&output=image
CJA:
I think you’re misreading the UAH chart, which is not intended to be a prediction. No trend goes on ‘forever.’
The UAH chart simply shows two things very clearly: that the climate fluctuates, and that rising CO2 has little or nothing to do with global temperatures.
Jeff Id has done several posts recently comparing trends between GISS, UAH, and RSS. He considers the hypothesized amplification factor between the surface and tropospheric data, comparison of short term variability between metrics, possible data errors, etc.
links:
http://noconsensus.wordpress.com/2009/01/06/more-fun-with-giss-temps/
http://noconsensus.wordpress.com/2009/01/09/rss-uah-giss-comparison/
http://noconsensus.wordpress.com/2009/01/14/give-a-kid-a-toy/
http://noconsensus.wordpress.com/2009/01/15/1853/
“If I am reading all of this correctly, there appears to be disagreements over the data of what the temperatures on earth actually are/were, or perhaps how to measure/adjust such temperatures for comparison’s sake [I don’t like massaged data, unless I am the masseur]. Indeed, based on the above quoted statement, there seems to be a disagreement over whether 2008 was warmer or slightly cooler than 1980 [after the massage].”
Both GISS and NOAA adjust the data. They both use different adjustment mechanisms and they both reach different conclusions.
There is, I believe, a new network under construction that will require no adjustments but it will be some years before we have enough data. People want “action” on the time scales of election cycles. We are talking warming one degree over a century. As we are currently not warming, it would seem reasonable to wait another 20 or 30 years to see what the trend from this new network shows but it has become a major political issue. People’s lifetime of research grants are at stake here if you are on the wrong “side” of the issue. You risk not getting published if you are on the wrong “side”. A scientist’s career is all about being published and cited by others.
It is about money and politics and people covering their careers. The new President’s “climate czar” was until her appointment on the board of directors of one of the largest carbon credit trading firms. Her husband is a lobbyist on energy issues. Gore produces “carbon credits”. Too many proponents have direct monetary interest in furthering the notion. Far too many scientists and researchers are being professionally blackmailed into silence under threat from being ostracized or having their funding cut off or of being refused publication. Many wait until they are retired to finally voice their real opinions.
To date have only evidence that CO2 is rising. We have no evidence that this rise will increase temperatures as models predict (in fact, the observations would indicate otherwise according to some). We have no indication that current temperatures are “unprecedented” or that rates of recent warming are “unprecedented”. We have no evidence that it is warming at all over the past 10 years.
Even the models don’t say that CO2 will directly increase the temperatures that much. They rely on CO2 causing other things to happen such as increased evaporation and assume that water vapor would be a “positive” feedback and accelerate the warming because it is a much more powerful greenhouse gas than CO2. But observations indicate that water vapor is a negative feedback. When you increase moisture you increase clouds which reflect light back onto space before can be converted to heat. Also, water is a working fluid for a natural refrigeration system that uses evaporation at the surface and condensation at the top of the troposphere to move a huge amount of heat from surface to high above much of the atmospheric CO2.
What we really have here are people using a “global warming” scenario to justify various regulation of energy production and industry. So they become extremely defensive when the underlying “hook” is threatened because it then threatens a greater agenda where billions of dollars and a lot of power is at stake.
It isn’t at all about science as far as I can tell.
Smokey,
I understand that the trendline is not meant to be predictive, but it is still misleading (and I think intentionally so). There is no time period on that chart where the slope of the trendline is anywhere near as steep as in the last few years.
This is an interesting way to look at it:
GISS vs UAH divergence since 1980
The (Excel) chart of the woodfortrees monthly data for each series is adjusted so that the linear trend lines diverge from zero in 1980. Moving year avg trend is also shown for each. This makes clear some interesting additional features. The UAH data is more variable and shows markedly less correlation with the linear trend. Also extreme years are much more extreme suggesting it is in fact more sensitive to annual temperature variations and the current downturn is much more extreme.
Richard Sharpe (13:50:47) :
“Also, could you tell us in what way UAH trends fail to obey basic physics and how you think all the things you mentioned bias the data.”
Isn’t it obvious? Co2 has increased and from well known laws of consensus the temperature must rise. 😉
Steven Hill (09:57:23) :
Wow, I am amazed at how hard they are trying to push this global warming thing. It appears that Obama is in, hook, line and sinker. Let’s see how the voters react when and if the utilities bills go through the roof sometime in the future. I want to see the reaction of a $.50 a gallon tax increase and CO2 taxes on generating plants.
In the ex-Soviet Union, bread to the masses was subsidized (cost about 10 cents per loaf, when available). “Bad” things were discouraged with artificially high prices (like grain to feed pigs). Pig farmers in the ex-USSR were found to be buying bread and feeding it to pigs, since it was cheaper than buying (sometimes unavailable) pig feed. (When found out they were, um, er, made into good citizens…) As we are now a Lange Type Socialist system, we will have similar dislocations.
I expect that consumption of fuel based energy will be discouraged, but food will be subsidized. I’m ready and able to ferment sugars, grains, and yes, even bread, and use the resultant alcohols for my heating, lighting, and driving needs… My car already runs on vegetable oil (new or used) so when they tax Diesel to death and subsidize food oils, I’m set. Just don’t get caught… I understand reeducation camps are hell on people who have working brains…
Vegetable oil, via biodiesel, can be run in oil heaters. Woodgas in modified gas burners… Lawn clippings anyone?
For a good time, google “wood gas generator” or “gasogene”. There are really fun things people do to make their car go…
http://www.gengas.nu/byggbes/index.shtml
http://www.woodgas.net/
http://www.woodgas.com/
And a couple of more, um, amusing ones…
http://freeweb.deltha.hu/zastava.in.hu/wood-gas.htm
http://ww2.whidbey.net/jameslux/woodgas.htm (I knew I could work Nazi’s in somehow 😉
(No, I don’t think we will really end up there, Obama’s too smart for that. At the first sign that the public is turning against ‘the movement’, he will have a cabinet / minister reshuffle, probably with some world event as pretext… Sort of a “Due to recent Russian actions wrt Europe, we must temporarily shift our emphasis to domestic coal while we work out the problems they are causing for the world.” This is just all in good fun and because I like having options for fantasy time – just after nap time 😉 But if I had a real full sized farm… )
Richard M,
You are absolutely correct that increased CO2 has a tendency to increase temperature. But the story is much more complicated than that.
There is no controversy that a doubling in CO2 would lead to a direct increase of about 1.2C. The theory of catastrophic warming is based on cumulative “feedbacks” which are calculated in climate models. Climate models are not simple by any stretch of the imagination.
Also consider that during the 1960s and 1970s, temperatures dropped so much that many people were worried about an ice age. Yet CO2 increased steadily during that period.
The simple cause and effect you are looking for is perhaps not so simple.
Seems my link got zapped. The image is here:
http://www.iforce.co.nz/i/fc1cef18956ae2a7ac491b97c3409f92.gif
I double dog dare this site to create a post on “The Divergence Between RSS and UAH.”
“In the ex-Soviet Union …”
I’ve invented a brief neologism, which is also self-explanatory, to avoid that lengthy phrase: XSSR.
Based on this: Manna from Heaven (err, Washington)
I don’t think we can expect NASA to change.
cce, there is a recent paper by Douglass and Christy as I recall which has an appendix discussing the differences and their reasons for preferring the UAH numbers.
Ya’ll may be missing something.
The most significant point on the difference chart is the huge drop in 1998. Why?
For a black helicopter/conspiratorial skeptic (not me), the answer is obvious. The boss at GISS is no dummy. He is trying to avoid the “Beaman” effect.
In the 1968 Olympics, Bob Beaman went 29.2 feet, breaking the old long-jump record not by inches, but by more than 2 feet. It took 20+ years for that record to be broken.
To show Global Warming effectively, you need to continually break records, even if by only a little (it grabs the same headline). A huge spike like 1998 would make it impossible, so he adjusted (homogenized) the numbers down as low as would still be a record high, but leave room for future headlines.
A successful strategy. By renewing his spread, he was able to get 2 more records and one near record before the current freeze hit and made the tactic unsupportable. Here’s a chart of the four temp data sets, gleaned from somewhere on WUWT in the past.
http://i40.tinypic.com/10p11mt.jpg
Note that the 1998 temp is reduced even below the RSS value. Clearly an effort to avoid the “Beaman” effect.
Clearly, that is, if you’re the conspiratorial type, and not like me.
Douglass and Christy is here: http://arxiv.org/pdf/0809.0581v1
Mike, if you look at my chart (comment at 15:47:48) you can see it isn’t just the 1998 peak that is lower – all the fluctuations are smaller in GISS than in UAH. So the smoothing effect is not a one-off but consistent.
ccm,
cce (16:18:07) :
I double dog dare this site to create a post on The Divergence Between RSS and UAH.
Excellent idea. I will take you up on that.
RSS has a comparison of RSS/UAH vs Radiosonde (and each other)
Steven Goddard (15:37:12) :
“Richard M,
The simple cause and effect you are looking for is perhaps not so simple.”
No argument here. It appears you missed the wink.
This is interesting – use Paul Clark’s excellent site to plot the slopes of UAH, RSS, Hadley and GISS together and it is clear that it is UAH that is the ‘odd man out’. Perhaps one would have expected the two satellite estimates to diverge from the surface analyses, but no – it seems it is Messrs Christy and Spencer who have the explaining to do ….
http://www.woodfortrees.org/plot/uah/trend/plot/gistemp/from:1979/trend/offset:-0.199/plot/rss/trend/offset:0.03/plot/hadcrut3vgl/from:1979/trend/offset:-0.128
Mike McMillan
I’m sold re the Beamon effect (I think he spells it with an ‘o’). I saw his jump on tv in 68.
We always must remember it is all about the perception, the politics, and selling the goods.
We in California have only a few more months to head this thing off, as the details of AB 32 get hammered out into binding regulations. 33 percent renewable-generated power, whereas a utility system begins to creak at around 20 percent; 37 mpg vehicles on average; low carbon fuel standard (bio-fuel of every sort); housing and commercial development in a vertical mode so less transportation required; cap-and-trade on carbon so our goods will cost more than anywhere in the world; the list goes on and on.
And the AGW’s have the recent weather in their favor out here…we are having a heat wave — it was 81 degrees at 3 pm this afternoon at LAX (Los Angeles International Airport). Sorry Anthony, as you do not like airport temperature measurements, and with good reason (miles of concrete runway for one thing). That short-term memory thing is hurting us out here due to the warmth.
The good news for California is there are several lawsuits filed by various parties to stop portions of the AB 32 requirements — automobile companies over the mpg issue; and an oil company sued over the bio-fuel issue, among others. These could delay things at least until the cooling is in full swing.
Maybe it is not such a good idea to “first, shoot all the lawyers.” 😉
Roger E. Sowell
Marina del Rey, California