Monday, November 30, 2009

Be Careful About Jumping the Gun

The CRU leaked/hacked emails are certainly eye-opening. And they are certainly being ignored by the American mainstream press for reasons that can only be political. But the smoking gun seems to be mainly the evidence of pressure placed on others by Jones, Mann and a few others and to dismiss and harass the skeptics and squelch their dissent.

Granted it's possible these scientists are maliciously using the recent temperature uptick to further personal needs and ideologies but that doesn't mean the uptick itself isn't occurring.

Some are saying it hasn't warmed since 1998 so that's proof we've stopped warming. Maybe so, but maybe not. Here's the US temperature graph since the late 1880s, with the blue rectangle around the period of great interest right now, 1998-2009:

The more important takeaway is the pronounced warming in the 30s, which rivals today's warming (and takes the steam away from CO2 being the only causative forcing) followed by an unexplained cooling between 1940 and 1980. But care should be taken to garner much meaningful trend out of the last 10 years. Take a look at the graph (crudely retouched by me to make a point) with the years from 1998-2009 erased and a rectangle around the years 1990-1997:

The same could have been said for 1990-1997--it's stopped warming. As we saw that wasn't the case. A strong el Nino hit in 1998 and we had record warmth, followed by several more years of record warmth. Ten years doesn't mean that much when dealing with a 25-50 year trend. None of this says one whit about causation, though.

Rush Limbaugh was going nuts today, saying these emails show that AGW is a complete fraud etc, and they may be, but conservatives should be careful here. There's nothing wrong with acknowledging that the globe is warming or that ice caps are retreating and glaciers are melting. They are. It's been going on since the mid 1800s as measured by a long term trend. The question is why, and that's where the CRU emails show the weak link.

Continuing to argue long term meaning from a ten year trend could come back to bite, and hard if after five or ten years we have several more record warm events and the chart begins to rise again. The warmists will use that to "wipe the grins off smug faces" and claim proof positive that man-made warming is real, and people may finally believe.

The better questions are asking them to explain the cooling period between 1940 and 1980 (when CO2 was rising) or the initial warming coming into the 1930s, or how the urban heat islands around cities might be skewing the overall database due to rising nighttime lows (many rural sites show less overall warming over the last 80 years). These questions seem to have few consensus answers.

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