Via Ace and Tigerhawk, we’re all probably better off if I don’t try to summarize it for you and you simply read this amazing post instead. Carefully, please. Including/especially the updates, noting in particular the conclusion of Update #3. Then read this post and see what sort of effort had to be made to expose the flaw here, notwithstanding — or rather, because of — the enormous political and financial investment that’s been staked on these numbers. I’d have noted the staggering irony of the role James Hansen is alleged to have played in it but Ace beat me to it so all credit to him. Remarkable, isn’t it, how we’re assured that this is the most important scientific issue of our time and yet one of the basic calculations from which the evidence is derived has to be reverse engineered from the data in order to check it. Can we at least get some peer review before we build the ark?

Here are the new numbers dating back to 1880. As you can see, there’s still a trend towards warming since the mid 1970s or so; the cooling period before that was, supposedly, the product of industrial sulphate pollutants inadvertently reflecting sunlight in the atmosphere, which cooled the planet. The sulphates have been reduced now and so, the theory goes, the warming has begun again. You’ll find the money data in table form here: 1998, which was once alleged to have been the hottest year in a millennium, is now the second hottest behind … 1934. 2001 used to be the eighth-hottest year on record but now, after the data was recalculated, it’s slipped out of the top ten, replaced by … 1939. To quote Coyote Blog:

All of these necessary revisions to surface temperatures will likely not make warming trends go away completely. What it may do is bring the warming down to match the much lower satellite measured warming numbers we have, and will make current warming look more like past natural warming trends (e.g. early in this century) rather than a catastrophe created by man. In my global warming book, I argue that future man-made warming probably will exist, but will be more like a half to one degree over the coming decades than the media-hyped numbers that are ten times higher.

Whether that’s true or not, I obviously have no idea. Expect some furious pushback about it from the Goracle’s acolytes very, very soon.

Exit question: Not counting Fox News, how much media attention do you suppose will be paid to this story?

Update (Bryan): “Former NASA guy” hat on for a second, this is a pretty big deal. Money quote from Coyote Blog:

I cannot get over the irony that in the same week Newsweek makes the case that climate science is settled and there is no room for skepticism, skeptics discover a gaping hole and error in the global warming numbers.

The discontinuity in the data should have been a serious red flag for Hansen et al, but what we’re probably seeing here is the effect of personality and agenda on the scientific process. They assumed they were right, and either discounted or didn’t even notice the discontinuity that occurred at 2000. When I say that personality had an effect, here’s what I mean by that. After Hansen became the most famous “silenced” scientist since Galileo and particularly since he was battling Bush, he became a titan to the vast majority of the people I worked with in the earth science field at NASA (an admittedly small slice of that field, but also the top couple of echelons of it at the Goddard Space Flight Center). Questioning him in any way invited hostile stares and could limit a career. When I say that agenda played a role, if you ever manage to get onto the GSFC and find yourself outside any of the couple of earth science buildings, take note of the bumper stickers on most of the cars. They’re faded and pealing and say in big, bold letters “Dean for President.”

That said, there were people within NASA’s earth science groups like Dr. Michael King who said that they found the agenda-driven science frustrating, an in particular the effect that overzealous public affairs officers were having on the way the science was being reported to the press. In one story relayed during a meeting I attended at Goddard in 2005, several of the scientists and visualizers talked about public affairs reporting on some Landsat (iirc it was Landsat) imagery of Mt. Kilimanjaro and its icecap. The satellite photos showed the moutain’s ice cap receeding due to seasonal change; public affairs reported the photos as evidence that global warming was causing the ice cap’s retreat. Public affairs was hyping the stories to the press, which in turn added even more hype. The public has been getting earth science reporting that’s hyped, squared.

Perhaps the deflation that Hansen ought to get due to his basic error on the Y2K bug in his data will spark a broader reevaluation of his work and of the way science is reported via press offices that are conduits of earth science to the public. It’s long over due.

Update (bp): Inconvenient timing.

The next decade will be a hot one, according to scientists unveiling the first 10-year projection of global warming.

The climate projection, published today in the journal Science, suggests that a natural cooling trend in eastern and southern Pacific ocean waters has kept a lid on warming in recent years.

And it will continue to do so, scientists say, but not for long.

The projection spans 2006 to 2015. “At least half of the years after 2009 are predicted to be warmer than 1998, the warmest year currently on record,” the researchers say in their report.

Not anymore.

Update: Then again…