Biases in the instrumental temperature record: the policy and communications context

Thursday, 18 December 2014: 3:00 PM
Kevin Cowtan, University of York, York, YO10, United Kingdom and Robert Way, University of Ottawa, Geography, Ottawa, ON, Canada
Global surface temperature plays a significant role in the public perception of climate change. However, observations are not uniformly distributed over the surface of the planet. The lack of data for the rapidly warming Arctic in the Met Office HadCRUT4 dataset has led to a systematic underestimation of the rate of warming over the past decade and a half. Smaller biases have also been detected in other versions of the temperature record.

This underestimation of recent temperature trends is one contributory factor (of several) to the apparent 'hiatus' in global warming. The use of the putative hiatus as an argument against action on global warming has created a social context in which what should have been a minor technical paper appeared to take on a much greater significance. From a scientific perspective, the apparent hiatus is irrelevant to our understanding of long term greenhouse warming, and should therefore have no bearing on policy. However the misinformation context into which science is communicated means that any scientific work can take on a policy significance which is determined not by the work itself, but by the societal context.

This raises challenging ethical questions for scientists. In an information environment in which interested parties have already attached policy implications to many aspects of climate science, it becomes impossible to publish or communicate a scientific work without implicitly taking a position. Different segments of the public have different and often contradictory perceptions of the scientific context, and as a result the words of the scientist may convey completely different messages to different hearers. Communicating science in a way which does not mislead is difficult, however abandoning the effort at communication can lead to the public being more misled.