Hadley and CRU left out important data

Why are Hadley and CRU withholding vital climate data from the public?

[Via Climate Progress]

No, not the stuff in the stolen emails — although the University of East Anglia and its Climatic Research Unit (CRU) have yet another statement out I’ll excerpt below. It notes “Over 95% of the CRU climate data set concerning land surface temperatures has been accessible to climate researchers, sceptics and the public for several years.”

No, the vital climate data that the Hadley Center and CRU are withholding from the public is the warming taking place in the Arctic (see “What exactly is polar amplification and why does it matter?“). And that missing data is why NASA’s Goddard Institute for Space Studies data are almost certainly superior to CRU’s data “developed in conjunction with Hadley Centre of the UK Met Office.”

Remember, “there are no permanent weather stations in the Arctic Ocean, the place on Earth that has been warming fastest,” as New Scientist explained (see here and here). “The UK’s Hadley Centre record simply excludes this area, whereas the NASA version assumes its surface temperature is the same as that of the nearest land-based stations.” Thus it is almost certainly the case that the planet has warmed up more this decade than NASA says, and especially more than the UK’s Hadley Center says.

Mean temperature difference between the periods 2004-2008 and 1999-2003 RealClimate has an excellent post on this very subject — “the ‘hole in the Arctic’ in the Hadley data, just where recent warming has been greatest” — with this great figure (and caption):

Figure. The animated graph shows the temperature difference between the two 5-year periods 1999-2003 and 2004-2008. The largest warming has occurred over the Arctic in the past decade and is missing in the Hadley data.

See also “Human-caused Arctic warming overtakes 2,000 years of natural cooling, “seminal” study finds.”

Thus contrary to what the global warming disinformers say about the recent temperature record, it is almost certainly the case that the planet has warmed up more this decade than NASA says, and especially more than the UK’s Hadley Center says.

So that’s why the NASA temperature record should be seen as more accurate, which puts 2005 as the warmest year on record, with 2007 just edging out 1998 for second warmest. This is “the hottest decade the planet has experienced in many thousands of years,” as climatologist Ken Caldeira puts it. NASA has reported June to October were the hottest on record.* And next year may well be the warmest on record.

So, no, there hasn’t been any recent “global cooling” even for the surface temperature record. And when you look at where 90% of the human-caused warming was expected to go — the oceans — you find steady warming over the past several years:

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NASA’s data includes more of the Arctic temperature change than the Hadley data, which mostly sees a big hole there. Thus the air temperature that the GISS record presents includes important data that the Hadley does not. Every model indicated that the Arctic would heat most. Only NASA really included this data.

So while the Hadley data is very important and is a useful, independent database for modeling (it is very useful for comparing changes over time in most of the world), NASA’s data would seem to represent a fuller representation of the world’s temperatures. And even the NASA data probably underestimates the total temperature increase.

Both sets of data are able to see trends but NASA’s would presumably see a larger trend because it includes more of the regions with the greatest changes int emperatures.

Also, remember that many people are discussing the temperature changes over land (which will be the temperature of the air) or in the shallow surface waters. It turns out, though, that the deeper ocean waters are a huge heat sink that have been soaking up excess energy in huge amounts. The possible effects of this excess heat on the deep ocean currents we depend on is worrisome.

This figure from Skeptical Science gives a measure of the huge difference in the heat from land measurements and deeper ocean temperatures.


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Figure 1: “Total Earth Heat Content [anomaly] from 1950 (Murphy et al. 2009). Ocean data taken from Domingues et al 2008.”

Thats small brown area is what most of us care about because we live on land not water. BUt that excess heat in the oceans may come back to affect us on land someday soon.

The amount of atmospheric heating, which we are most concerned with, pails in comparison with the amount of excess heat the ocean is dealing with. I would worry that this heat will either eventually be radiated to the atmosphere, further increasing its temperature, or perhaps cause changes in thermohaline circulation since there would be a lower heat gradient from the equator to the higher latitudes. I’ll have to see what people say about that.