Republicans in the US Congress hunt for evidence that temperature records are politicized.
National Oceanic and Atmospheric Administration Earth System Research Laboratory in Boulder, Colo.PHOTO: BYUNGHWAN LIM/GETTY IMAGES
With their latest subpoena to the Obama administration, House Republicans risk descending into a rabbit hole, albeit a useful one.Lamar Smith, the Texas GOPer who runs the House science and technology committee, has been seeking, voluntarily and then not so voluntarily, emails and other internal communications related to a study released earlier this year by the National Oceanic and Atmospheric Administration. The study, by adjusting upward temperature readings from certain ocean buoys to match shipboard measurements, eliminated the “pause” in global warming seen in most temperature studies over the past 15 years.Let’s just say, without prejudging the case, gut instinct has always indicated that, if there’s a major global warming scandal to be discovered anywhere, it will be found in the temperature record simply because the records are subject to so much opaque statistical manipulation. But even if no scandal is found, it’s past time for politicians and the public to understand the nature of these records and the conditions under which they are manufactured.This is where those who confuse science with religion, and scientists with priests, take umbrage. Unfortunately, NOAA has proved itself pliable to the propagandizing urge. Witness its steady stream of press releases pronouncing the latest month or year the “warmest on record.” It always falls to outsiders to point out that these claims often rest on differences many times smaller than NOAA’s own cited margin of error. Case in point: When President Obama declared in January that 2014 was the warmest year on record, it had only a 38% chance of being hotter (by an infinitesimal margin) than other hottest-year candidates 2010, 2005 and 1998.It doesn’t help that NOAA’s sleight of hand here seems designed precisely to conceal the alleged “pause.” The inconvenient hiatus in global warming showed up just as temperature measurement became more rigorous and consistent; just as China overtook the U.S. as champion emitter; just as 30% of all greenhouse gases released since the start of the industrial revolution were hitting the atmosphere.
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.