Ben Santer, Matthew England, Ed Hawkins, Michael Mann, Gerald Meehl, Yu Kosaka, and Shang-Ping Xie sent a polite and informative letter to Lamar Smith. Smith had misused a paper they had published to claim that there was a global warming “pause”, and to claim that their work had somehow invalidated the observations of another climate research group — it was a crude attempt to pit two groups with subtle differences in interpretation against one another to cast doubt where there is none.
What’s nice about the letter is that it carefully explains that scientists can disagree about some things without losing respect for one another, if the work is done well, and that they can agree completely on issues that Lamar Smith does not like.
Finally, we would like to emphasize that Karl et al. and Fyfe et al. agree on the most important scientific points. We agree that human influence on climate is real, is large, and is ongoing. We agree that this influence is primarily due to fossil fuel burning, and to the resulting human-caused changes in atmospheric levels of heat-trapping greenhouse gases. We agree that human-caused changes in greenhouse gases should lead – and do lead – to global-scale warming of Earth’s atmosphere, oceans, and land surface. We agree that we have identified large global warming signals in the observed surface temperature changes from the late 19th century to the present, in the satellite atmospheric temperature data that have featured prominently in recent Congressional hearings, and in ocean heat content measurements.
And we agree with Karl et al. that on top of the underlying global-scale warming trend over the past 150 years, we should see – and do see – natural, decade-to-decade ups and downs caused by internal variability, volcanic activity, and changes in the Sun’s energy output. These decade-to-decade fluctuations in warming are not a scientific surprise. They have been discussed at length in every national and international assessment of climate science. Sometimes the “ups” act in the same direction as human influences, leading to accelerated warming. Sometimes the “downs” lead to a short-term decrease in warming. Our disagreement with Karl et al. about the size of the most recent short-term fluctuation does not call into question the reality of long-term human-caused warming.
Unfortunately, this case is being made to Lamar Smith, darling of the Heartland Institute, a lawyer with zero training in science who wants to redefine the scientific method, who has demonstrated his impenetrability to science over and over again. It’s important to continue to try and educate our Republican dingleberries as well as possible, but I have no confidence at all that this approach will sink in.
Maybe the rest of us can learn from the letter, though.