Green Myth-Busting: Global Average Temperature
Myth: Global temperature data is inaccurate and/or too sparse to be able to establish a meaningful average temperature over the entire planet. Therefore, any claims of global warming are unfounded.
Fact: NASA has collected and acquired massive amounts of temperature data from various sources, including land-based, meteorological stations, sea surface temperature measurements from ships, and measurements taken from satellites. This data encompasses the entire planet, and is run through a method that is explained on NASA’s website, which results in a statistically significant global average temperature.
The first thing to note here is that there are not many who still make this argument, at least not among climate scientists. The IPCC, in its latest report, actually states that global warming is "unequivocal". Even skeptical scientists, such as Richard Lindzen and John Christy, will admit that we are indeed warming. Their only argument is against the cause of the warming, which is where most skeptics’ arguments have shifted. This should be a clue that there is no argument against warming, however some continue to insist that the planet is not warming.
It seems that the major impetus for the recent resurgence of this argument is a website, www.surfacestations.org, which attempts to question data collection equipment. This is actually a very nifty little trick. This site, launched in June of this year, has established a fairly large following. These devoted followers are commissioned to go out and take pictures of the US meteorological stations. Armed with these pictures, surfacestations.org scrutinizes them, looking for indications that they might be susceptible to a warm bias. This has filled many contrarians’ minds with the idea that the entire temperature data set is flawed, which is ultimately the point. Not surprisingly, there is no mention on the site of existing methods for removing biases from temperature measurements. First, the thermometers are now protected by Stevenson screens (emphasis added):
A Stevenson screen or Instrument shelter is a meterological screen to shield instruments against precipitation and direct heat radiation from outside sources, while still allowing air to circulate freely around them. It forms part of a standard weather station. The screen creates, as near possible, a uniform environment in relation to the air outside. - Wikipedia
Second, NASA’s GISTEMP compares urban stations to rural stations, in an attempt to further remove any potential biases:
We modify the GHCN/USHCN/SCAR data in two stages to get to the station data on which all our tables, graphs, and maps are based: in stage 1 we try to combine at each location the time records of the various sources; in stage 2 we adjust the non-rural stations in such a way that their longterm trend of annual means is as close as possible to that of the mean of the neighboring rural stations. Non-rural stations that cannot be adjusted are dropped. - NASA GISS
Another common argument is that we simply don’t have enough temperature data to be able to compute a global average temperature. This argument usually comes with a map of the world, showing the locations of existing surface meteorological stations. Obviously, on such a map, there are very large areas that are not covered (oceans, deserts, mountain ranges, etc.). However, NASA states that they have sufficient data, dating as far back as 1880:
The NASA GISS Surface Temperature Analysis (GISTEMP) provides a measure of the changing global surface temperature with monthly resolution for the period since 1880, when a reasonably global distribution of meteorological stations was established…We limit our analysis to the period since 1880 because of the poor spatial coverage of stations prior to that time and the reduced possibility of checking records against those of nearby neighbors. - NASA GISS
A major problem for both of these arguments is that they only focus on land-based temperature readings. This is because there is a preponderance of evidence in favor of global warming outside of those temperature measurements, which are completely ignored by these objections. In order to truly call global warming into question, one would also have to prove satellite data, borehole analysis, glacial melt, sea ice melt, sea level rise, proxy data, and rising ocean temperature to be flawed.
UPDATE: A new instance of this questioning of temperature data occurred when NASA made some small corrections to data at the turn of the millenium, thanks to a tip from Stephen McIntyre from Climate Audit. This was a good tip, and NASA’s data is now more accurate for it, but some skeptics have tried to misrepresent it as proof that NASA’s temperature data is faulty. Recently, Fox News provided an excellent example of this misrepresentation:
On Special Report, Jim Angle reported that NASA was forced "to admit it was wrong when it said that 1998 was the hottest year on record" and that NASA "now says 1934 was the hottest year, followed by 1998, then 1921." But Angle did not inform viewers that NASA’s revision affected annual temperature rankings for the United States only; it had no effect on the annual global temperature rankings. - Media Matters
As the fine folks at Media Matters pointed out, while the change did result in 1934 topping 1998 as the hottest year in the US, it had literally no effect on global temperature trends, and actually even a very miniscule effect on US trends. Looking at the global temperature graph below, one can see that the global warming trend is still very much intact:
Tags: Climate Change, global warming, Green Myth-Busting, NASA, Science and Tech
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September 26th, 2007 at 9:02 am
As another basement brainiac can I please ask a sort of kindergarden maths question?
Given that the average global temperature is 15 degrees c (or there abouts), and the average temperature of the human body is 38 degrees.
Also Given that the human population has increased by 2.7 times sine 1950 (when all this global warming data seems to start) from 2.5 billion to 6.7 billion in July 2007.
Can anyone tell me, mathematically of course, the net increase in global temperatures resulting from the conversion of “average global temperature” non living tissues at 15 degrees c to this incredible human radiator at 38 degrees.
OH and don’t all those extra humans breath our CO2 even before they drive their cars and heat their homes?
Seems to me all these boffins have their heads so far up their backsides they are missing the bleeding obvious and fiddling around with symptoms rather than addressing causes.
September 26th, 2007 at 1:23 pm
I would say group of people called to become an experts in a particular field of study could certainly illustrate a populational bias.
If someone’s love of the environment drives them to the field of environmental science then it would make sense that they would come into the field of study with a bit of bias. And certainly their environmental science teachers and curriculum are going to do very little to abate this predisposition.
Just as when you ask a policeman what is most important he will reply “law and order” and when you ask a teacher what is most important he will reply “education”; in the same sense someone who has devoted his life to some eclectic subset of the study of environmental science will give it apocalyptic importance over other important political and socio-economic problems.
October 8th, 2007 at 5:01 pm
Keep this in mind:
1. Many scientists/experts claim the global tempurature is dropping.
2. Though one part of the artic shelf is melting, why is no one talking about the backside of antarctica who’s ice mass is increasing? (true story)
3. Does a global cause increase funding for politicians fighting “a cause” does it give them a campaign to fight for?
4. Does creating a global cause increase scientific funding to increase new technologies?
It plays in favor of many people for global warming to be true. It gives a cause for panic, which will always drive money. How much success would Gore and other politicians have if global warming was non existant? How much funding would scientisits recieve from those needing to show “proof” of global warming?
And finally, has “science” never been wrong? Has it not repeatedly occured that the “scientific” and accepted truths acctually turned out to be false? “Earth as center of universe” “Earth’s surface being flat” just to name a couple.
Should we not question science when science does not agree with itself?
Would politicians/government ride a trend that was bringing in money and support from the people true or not?
Just some questions to take a look at. Remember, smoking wasn’t always bad for you, or was it, and we just thought it wasn’t for a long time?
October 24th, 2007 at 10:18 am
Hi T
Quite!
March 5th, 2008 at 2:00 pm
In light of the recent reports from NASA and three other climate review organizations worldwide, that the average temperature of the planet decreased nearly a degree in 2007, capping off nearly 10 years of absolutely no increase in global average temperatures, wouldn’t you agree that your information is pretty much all crap?
November 9th, 2008 at 12:21 am
Who ever wrote this is a moron the graph depicted isn’t even close to accurate. All of you dimwits don’t bother to mention that the primary greenhouse gas is water vapor. Most of the carbon that is in the air is actually the release of carbon from melting ice and warming water not from humans. the carbon that humans use only account for –.117% of the carbon in the atmosphere this is so negligible its hardly worth mentioning. All of this global warming crap is a scam conjured up by the politico to harass more money out of the citizens in the form of carbon taxes. Global warming is a natural occurrence period the one good aspect to natural global warming is the fact that we have longer growing seasons to (get this now) grow more food. Imagine that the more carbon in the air the more plants thrive. After all even in the youngest grades earth science tells us plants take in carbon and let out oxygen wow more oxygen we can all breathe easier now. This whole subject is just idiotic either get more education or quit writing these dimwitted fascist articles you leftist trash..
November 9th, 2008 at 2:06 am
Hello, Bob. Let’s see… where to start? You’ve spouted quite a few skeptical myths in one comment here.
1. If you think the graph is wrong, please provide a link to one that you consider to be more accurate.
2. It is true that water vapor is a more prevalent greenhouse gas, but it is a feedback, rather than a forcing. If you’re not familiar with those terms, please look them up.
3. It is also true that much of the carbon dioxide in the atmosphere is natural. However, this is yet another red herring, because it does not consider the INCREASE in carbon dioxide, which is a product of human activity. You see, there is a process called the carbon cycle, by which the majority of the naturally occurring carbon dioxide is subsequently absorbed by trees and oceans.
4. It is also true, like your other red herrings, that there could be SOME positive impacts from warmer temperatures and increased carbon dioxide, but they are greatly outweighed by the negative impacts that will result, such as rising ocean levels and more droughts.
PLEASE respond, so we can have this debate. Thanks.