I confess, I’m confused by Willis Eschenbach’s latest post at WUWT, titled “Cooling Down the Land.” It begins with this graph (of a mere 18 years’ data):
Which makes me wonder, where can I get this CERES global surface temperature product? Turns out CERES doesn’t make one, but if you delve into the comments (ewww!) one hears that Willis has an algorithm to make one based on CERES data. Ew.
How about actual global surface temperature since March 2000? I’ll add 14.5 to the NASA data to make it look a little like Willis’s data:
Curiously, his graph says “Trend = 0.07°C/decade” and talks of a p-value that’s “not statistically significant.” Mine says the rate is 0.20 °C/decade, with a +/- of 0.09 °C/decade (that’s 2sigma), which is definitely statistically significant.
Then there’s the part where he talks about ocean warming since March 2000 but land areas not warming. After all, it’s in the title. His claim seems rooted in this map he gives of the rate of temperature change since March 2000, showing “cooling” over most land areas:
I don’t have much confidence in the data he’s using for surface temperature. Add to that little or no confidence in his ability to determine the trend, and you get some serious skepticism of his claim.
For land areas (leaving out the oceans), I prefer the data from the Berkeley Earth Surface Temperature project, which tell me this (worldwide, land areas only, since March 2000):
That’s not cooling as Willis claims, it’s warming. Even faster than the global average. And yeah, it’s “statistically significant.”
But what about the map? Berkeley provides gridded data too, and here’s my map of the trend in surface temperature since March 2000, over the land areas of the world (red is warming, blue is cooling, bigger is faster):
There are some blue splotches on the map, no doubt. But hey, that’s to be expected given the uncertainty level in a mere 18 years’ data. Red areas dominate, because face facts people, the land areas are heating up faster than the oceans.
A post titled “Cooling Down the Land” claiming that the land is cooling, is rather effectively refuted by the fact that the land is heating up faster than the oceans. Which are heating up too, despite the claim that the global trend since March 2000 is “not statistically significant.” Actually making these claims public, may be the biggest lapse of judgement.
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