Global Cooling? Not So Much...

So... Have you heard the one about "global cooling"? This comes up from time to time, and is almost always parroted by skeptics as definitive proof that global climate change is The Big Lie. People often "prove" this claim by pointing to impressive looking graphs that show a dramatic cooling trend starting after 1998. These claims have been repeatedly debunked, of course. The basic trick in their statistics and graphs has been that 1998 was an anomaly. It was an unbelievably hot year, because of the strongest El Nino effect of the century, and so if you start your graph with 1998 on the left-hand side, it looks like the world has been cooling since then. Well, debunking these claims just got a bit easier. Joe Romm has the latest from the NASA Mean Surface Temperature dataset:

It was the hottest April on record in the NASA dataset. More significantly, following fast on the heels of the hottest March and hottest Jan-Feb-March on record, it’s also the hottest Jan-Feb-March-April on record.

The record temperatures we’re seeing now are especially impressive because we’ve been in “the deepest solar minimum in nearly a century.” It now appears to be over. It’s just hard to stop the march of manmade global warming, well, other than by reducing greenhouse gas emissions, that is.

Most significantly, NASA’s March prediction has come true: “It is nearly certain that a new record 12-month global temperature will be set in 2010.″

So, to get it straight, we set a few records here:

  1. April 2010 was the warmest April in recorded history (incidentally, March 2010 was the hottest March in recorded history as well).
  2. The 4 month period from January - April 2010 was the hottest similar period in recorded history.
  3. The 12-month period from May 2009 - April 2010 was the hottest 12-month period in recorded history (the record we just beat was originally set in 2007).

Oh, and those graphs the deniers always use to "prove" that the Earth has been cooling, and not warming? Krugman took that raw data and made a little graph of his own:

So, good job on the whole cranking the heat thing all around. I'd like to say that we'd love you for it up here in Maine, but I suspect that when those temperature and water levels rise, all those millions of displaced people will probably be heading up this way.