9 of the top 10 hottest years globally have occurred over the past decade, when measured using three different global temperature data sets. The top 20 warmest years have all occurred during the last 24 years.
How do the record high temperatures over the spring and summer in the US compare on a global basis? While numerous articles on global temperature trends exist [1], I decided to go to the primary temperature data sources to find out. Below I have created a list of the 20 warmest years on record globally, using three data sets: NASA GISS, the UK Meteorogical Office, and NOAA / UAH [2]. While the three data sets vary in length from 40 to 150 years, the 20 warmest years turn out to have all occurred in the last 24, making it possible to construct an average temperature for the hottest 20 years.
| Rank | Year | Global Avg Temp (F) [3] |
|---|---|---|
| 1 | 2010 | 58.28 |
| 2 | 1998 | 58.22 |
| 3 | 2005 | 58.15 |
| 4 | 2007 | 58.06 |
| 5 | 2002 | 58.05 |
| 6 | 2009 | 58.04 |
| 7 | 2003 | 58.03 |
| 8 | 2006 | 58.02 |
| 9 | 2011 | 57.98 |
| 10 | 2004 | 57.90 |
| 11 | 2001 | 57.89 |
| 12 | 2008 | 57.75 |
| 13 | 1995 | 57.70 |
| 14 | 1997 | 57.68 |
| 15 | 1999 | 57.65 |
| 16 | 1990 | 57.64 |
| 17 | 1991 | 57.64 |
| 18 | 2000 | 57.64 |
| 19 | 1988 | 57.59 |
| 20 | 1987 | 57.54 |
Since this is a divisive topic prone to political obfuscation, it’s worth noting that both the NASA Goddard Institute and the UK Meteorological Office officially support the theory of anthropogenic global-warming, while the research scientist responsible for the University of Alabama-Huntsville data set does not support this theory.
[1] This has been a popular topic: Economist, Live Science, ArsTechnica, Science Daily, and Wikipedia
[2] Here are the original data sets:
GISS Data: http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts.txt and www.movingandstoragesite.com moving and storage
NOAA/UAH: http://vortex.nsstc.uah.edu/data/msu/t2lt/resume builder online/uahncdc.lt
Hadley Meteorological Centre UK: http://www.metoffice.gov.uk/hadobs/hadcrut4/data/download.html#regional_series
[3] The data in this blog post was constructed by averaging data from the three underlying data series. The NASA GISS estimate of global mean baseline temperature of 14 degrees Celsius was used to adjust the temperature deltas provided by the original data series in order to show global mean temperature in Fahrenheit terms here.
True Cost - Analyzing our economy, government policy, and society through the lens of cost-benefit 
Well, there are some serious problems here, both in the comments and in the original post. First of all we should not be talking about “belief” in global warming per se, since belief is not something associated with science. I find it odd that individuals dedicated to logic and science insist on damning individuals using ad hominum attacks, as opposed to discussing their data and theories rationally. “You either believe in the scientific method, or you believe in magic.” I was not aware that the scientific method required “belief”.
Secondly, it is poorly understood by most global warming enthusiasts that there are two, completely separate theories of anthropogenic global warming. One is the purely physical effect of carbon dioxide in the atmosphere. This is a relatively small component of the predicted warming, and I’m fairly certain that a vast majority of scientists agree with the theory. Such warming is unlikely to be catastrophic, and indeed, we may have already experienced the majority of such warming that may occur. The second theory, the one that is poorly understood, is the climate sensitivity theory. This posits that relatively small additions of carbon dioxide will have outsized impacts on temperature, due to various environmental multipliers that exist in the climatological system So far this theory appears to be entirely incorrect – the outsized effects predicted have not materialized, and so far the global temperature increases we have measured are not consistent with such a theory.
No one disputes the fact that the current temperatures are much higher than they were in the past. Or that carbon dioxide concentrations have increased. However, correlation is not causation. The question should be, how much did the temperature increase before carbon dioxide concentrations increased, and how much after the increase? If you had bothered to graph your data, you would notice that for the 40 year period from 1910 to 1950 (pre-carbon dioxide increase) the Earth warmed 0.4 degrees. The next 40 year period from 1950 to 1990 the Earth warmed 0.3 degrees. From 1990 to today (24 years), the Earth warmed another 0.3 degrees. Currently, carbon dioxide continues to increase, but warming seems to have stalled. I would posit, just based on the data, that there is a natural warming cycle occurring (how else to explain 1910 to 1950?), and that the anthropogenic contribution to warming is fairly small, probably based simply on the physical effects of carbon dioxide in the atmosphere, and climate sensitivity is very low (in fact there may even be a negative feedback, since the observed warming is actually a tad below what I would have expected). Stepping back from the problem, it doesn’t make sense that the climate, which has been fairly stable for millions of years, is easily perturbed by relatively minor additions of carbon dioxide. Physical systems with large sensitivity tend to be unstable, and certainly do not last hundreds of thousands or even millions of years.
And some religios people see it as, “Wow, we were given something great and have corrupted it with outr our industriousness, laziness and pride. Unfortunately, a poor understanding of others leads to ignorance. 1st and formost, most Christians do care about this planet. I would amagine that if you really looked hard, you would find that much more anti-creation scientist are doing harm to this planet then Christians. Furthermore, some of the most conciencious scientists are beleivers! My christian perspective, is definilty leaning towards a global warming trend, that would, very likely, be related to our activities. Where my perspective differes from the journals is in the source. I do beleive in the “understandings” shared about the greenhouse gasses is a important component. But the real energy needed to heat this planet up is coming from the our desire to harness the power of the universe, nuclear. The amount of atomic weapons testing done since the mid 40′ and the 600 nuclear reactors spread around the planet, releasing HUGE amounts of energy in the form of latent heat is not onlyy warming the rivers and oceans, but also the atmosphere!. The insulating gasses, ensure that all that heat doesn’t leave. Will you consider that in a scientific, objective, truth seaking manner?
The two guys who manage the Alabama Huntsville effort are both devout Christians.
Sorry, but if you believe in magical beings who conjure the world into existence, with no evidence of this fairy tale’s validity (the Bible is not evidence, it’s testimony), then you’re not really qualified to do difficult science.
You either believe in the scientific method, or you believe in magic.
The denialism with respect to climate change is based on two major factors:
1) religion. if you think there’s a God who gave you dominion over the earth, then obviously, you’re free to pollute it as you see fit. some religious people also see it as “it would be arrogant for us to think that we can change God’s wonderful creation in any noticeable way”.
2) libertarianism, or as I like to call it “you’re not the boss of me”. libertarians just don’t ever want to be told that something they’re doing might be harmful, and thus maybe they should do less of it. it’s beyond childish.
Dr Roy Spencer does “support” the theory of anthropogenic global warming. Where he differs from the mainstream, in terms of his scientific beliefs, is in estimating a very low sensitivity of the climate to carbon dioxide.
Almost no qualified scientists deny the basic theory of global warming, which is:
1. We (humans) are adding long-lived greenhouses gases to the atmosphere.
2. They are warming the planet.
The people you find denying this are not scientists. In general, the controversy about AGW in the media and in the political discourse is ideological, like the opposition to Darwinism, the anti-vaccine movement, or the people that deny we landed on the moon.
There are of course many areas of significant scientific debate and uncertainty, but these center not around “happening” and “not happening” but typically around how much, how fast, how bad.
As an economics-type person you may want to Google “Nordhaus,” who’s written a number of papers on costs. I have a little amateur overview of some of the climate change cost literature here: http://theidiottracker.blogspot.com/2011/12/minor-myths-do-some-economists-think.html