Powerline: A Caveat On The 'Global Warming' Emails

From Powerline:

I've written a lot about the East Anglia emails, here, here, here and here. I think the emails and other documents are damaging to the cause of the partisans of anthropogenic global warming, mostly because they stand exposed as exactly that--partisans, engaged in a political rather than scientific enterprise.

However, while I did mention it in the first post linked above, I haven't emphasized the email that has gotten the most attention, and even inspired t-shirts that say "Hide the Decline." Many have viewed this email as a smoking gun, showing that the climate alarmists have used "tricks" to hide the fact that global temperatures are declining rather than rising. Here it is [editor's note: in the illustration above]; click to enlarge.

On its face, the email seems damning. The problem is that the interpretation it is being given doesn't make sense. If it had been written in the last couple of years, then sure: it would be plausible that climate alarmists may have been jiggering their data to hide the fact that temperature has been flat or declining for the last decade. But the email was authored in November 1999. At that time, there was no decline to hide. 1998 was, by all accounts that I'm aware of, the warmest year of recent times. 1999 is precisely when alarmists could present the strongest case that the earth was warming (whether due to human activity, of course, is another question).

So I seriously doubt that this email has the significance that is being attributed to it. For what it's worth, though, the explanation that Michael Mann, a recipient of the email, gave to the New York Times doesn't seem to make much sense either:

Dr. Mann, a professor at Pennsylvania State University, confirmed in an interview that the e-mail message was real. He said the choice of words by his colleague was poor but noted that scientists often used the word "trick" to refer to a good way to solve a problem, "and not something secret."

At issue were sets of data, both employed in two studies. One data set showed long-term temperature effects on tree rings; the other, thermometer readings for the past 100 years.
Through the last century, tree rings and thermometers show a consistent rise in temperature until 1960, when some tree rings, for unknown reasons, no longer show that rise, while the thermometers continue to do so until the present.

Dr. Mann explained that the reliability of the tree-ring data was called into question, so they were no longer used to track temperature fluctuations. But he said dropping the use of the tree rings was never something that was hidden, and had been in the scientific literature for more than a decade. "It sounds incriminating, but when you look at what you're talking about, there's nothing there," Dr. Mann said.

Unfortunately, the leaked emails surrounding the one in question don't shed any further light on the question. So that's where it sits. But the bottom line is, I don't think the warmists were hiding a temperature decline as of 1999, because temperatures weren't declining then. Ten years later, it could well be a different story.

UPDATE: Small Dead Animals locates "hide the decline" in leaked East Anglia computer code; click to enlarge:

That's fun, to be sure, but the problem is that our knowledge of temperatures post-1960 has nothing to do with tree rings. What this episode shows, I think, is that tree ring studies are useless, which we also noted here. Is that significant? Absolutely: tree-ring studies are the main support for the AGW conclusions reached by the U.N.'s IPCC report, which in turn is the U.S. government's only basis for cap and trade, etc.

For the global warming alarmists, it's any port in a storm. Use data as long as it supports your fanatically-held position, delete it as soon as it diverges.

FURTHER UPDATE: It would be possible for the Obama administration to be more out of touch with contemporary science, but it wouldn't be easy:

Putting his prestige on the line, President Barack Obama will personally commit the U.S. to a goal of substantially cutting greenhouse gases at next month's Copenhagen climate summit. He will insist America is ready to tackle global warming despite resistance in Congress over higher costs for businesses and homeowners.

Obama will attend the start of the conference Dec. 9 before heading to Oslo to accept the Nobel Peace Prize. He will "put on the table" a U.S. commitment to cut emissions by 17 percent over the next decade, on the way to reducing heat-trapping pollution by 80 percent by mid-century, the White House said.

The problem is that Obama knows absolutely nothing about the issue of climate, much as he knows little or nothing about the economy. I sincerely doubt that most Americans want to impoverish ourselves in order to satisfy a bunch of climate "scientists" who, we now know, happily sacrifice truth to political ideology and financial interest.

PAUL adds: The other problem, I think, is that Obama doesn't seem to know much about our system of government. He can't deliver on the kinds of promises he apparently intends to make without the cooperation of Congress. And even this session of Congress -- the most compliant he's ever likely to have -- hasn't felt like cooperating with him on this issue.

FINAL UPDATE: Climate Audit has, I think, the definitive explanation of "hide the decline." The decline being hidden is that reflected by tree ring data in recent years. The point, as suggested above, is that narrowing tree rings during a time when we know temperatures were rising proves that measuring the diameter of tree rings is a worthless way to measure world-wide temperatures. That's a big problem, since such proxy data are the basis for the alarmists' purported knowledge of temperatures in earlier eras. This also ties in with Keith Briffa's apparent manipulation of tree ring data to minimize the Medieval Warm Period, which we wrote about here.

Key point of all this -- Comrade Soetero and his Congressional fellow travellers are moving forward to cripple the US economy, despite the gaping hole in the rationale for any action.

Any questions as to why?