A number of recent studies indicate that 97-98% of actively publishing climate researchers support the conclusions of the Intergovernmental Panel on Climate Change in terms of anthropogenic global warming (AGW). However, a large percentage of the public continue to believe that there’s a close division of opinion in the scientific community. As a new study by Rasmus E. Benestad, et al. in the journal Theoretical and Applied Climatology suggests, this includes many undergraduate students in the United States. This is the reason that I always devote a full class in my climate change courses to discussing the specific arguments of climate skeptics. The Benestad study utilizes an analytical tool to test the results and methods used in high profile 38 contrarian papers (grouped into five categories based on analytical setup, statistics, mathematics, physical and representation of previous results), seeking to replicate and test the results and methods in these studies.
The study could be a useful reading for a teaching module on the arguments advanced by those who challenge the tenets of AGW, as well as providing some broader lessons about the nature of scientific research and the interface of scientists and the public.
Among the conclusions from the study were the following:
• Most of the studies across the categories failed to cite or address relevant literature that proffered evidence or conclusions counter to their conclusions;
• Many of the studies failed to compare models against independent values that were not deployed in the development of the study, which is critical to prevent curve-fitting;
• Many studies engaged in false dichotomy reasoning, such as arguing that warming was attributable to solar activities, while not acknowledging that greenhouse gas forcing could be a co-existing reason;
• Many of the studies employed spectral methods, which almost inevitable finds cycles or periodicities, even when they may not exist;
• A number of papers were published in journals that were far abreast from the field of climate change research, presenting the question of whether the editors were likely to be able to identify qualified reviewers.
The study suggests the need for openness and transparency to facilitate access to open source code and data that can facilitate replication to assess the validity of study findings. The researchers also argue that IPCC assessment reports might be more compelling to the public it is also made it source code and data available.