Republicans in the US Congress hunt for evidence that temperature records are politicized.

Presumably the hunt will now be on among House Republicans for evidence that NOAA scientists selected only those rejiggerings that would make the pause disappear. Good luck with that. Not only are the adjustments, corrections and interpolations eye-glazing—ground temperatures must be tweaked to offset growing urbanization, polar temperatures for the fact that we don’t have measurement data for long periods of history, etc. Past records must be assembled from measurements not under control of today’s researchers, using an uncertain mix of devices and practices. Where records don’t exist or are deemed inadequate, scientists incorporate what they call proxies.
Researchers will surely be prepared to justify each and every tweak, but it seems all but impossible to bias-proof the choice of which adjustments to make or not make. By the count of researcher Marcia Wyatt in a widely circulated presentation, the U.S. government’s published temperature data for the years 1880 to 2010 has been tinkered with 16 times in the past three years.
And, when all is said and done, it’s still not clear that assigning an “average” temperature for the planet for a year is a meaningful way to capture climate change. Or that claims to detect differences from one year to the next of 2/100ths of a degree are anything but exercises in false precision.
It would be astonishing if human activities were not having some impact on climate, but the question has always been how and how much. Evidence of climate change, of course, is not evidence of what’s causing climate change. Yet three certainties emerge from the murk: Carbon dioxide is a greenhouse gas; atmospheric concentrations of carbon dioxide have increased significantly due to fossil-fuel burning; and the reward system in climate science is heavily tilted toward forecasts and estimates that see a large human effect.
Unfortunately, it’s also true that many of us cannot tolerate making up our minds under conditions of uncertainty. Uncertainty is especially the enemy of passion. That’s why so many who proclaim themselves “passionate” about global warming cannot string together two sentences indicating any understanding of the subject.