Very few Americans are aware of the overwhelming scientific consensus on global warming (Maibach 2013). There’s a huge gap between the agreement the public thinks there is between scientists and the actual agreement among scientists. It’s because of this lack of awareness that several studies investigated what the agreement is among scientists.

When researchers surveyed climate scientists on the cause of global warming 97% of the actively publishing climatologists said that “human activity is a significant contributing factor in changing mean global temperatures” (Doran 2009) Researchers found the same patterns when they analysed public statements of climate experts (Anderegg 2010). When researchers looked into how the scientific consensus on global warming evolved from 1996 to 2009 they found a steady increase in the agreement among scientists (Bray 2010). The latest survey on the scientific literature found that 97% “endorsed the consensus position that humans are causing global warming” (Cook 2013).

The latest paper investigating the scientific consensus is ‘Scientists’ Views about Attribution of Global Warming‘ by Bart Verheggen. He and his colleagues surveyed over 1,800 climate scientists and their results confirm the consensus that global warming is predominantly caused by human greenhouse gases. He also found that this consensus gets stronger the more expertise scientists have, confirming the results found by studies like Doran 2009 and Anderegg 2010.

One of the interesting results from this paper is that the attribution statement in the IPCC 2007 report may lead to an underestimate of the greenhouse gas contribution to global warming. This is because the net warming it reports includes the cooling effects of aerosols which partly masks the warming caused by greenhouse gases.

This survey also found that the media exposure of contrarian positions is higher in the media, contributing to the consensus gap. This confirms the results from Boykoff 2013 which also found that in the media contrarian positions are over represented. Despite the overwhelming evidence in the scientific literature showing that we’re causing global warming.

I interviewed Verheggen on these results, their meaning, and how this compares to other consensus papers. During the interview we talked about the findings I already mentioned here, and some other very interesting details Verheggen found. I hope you’ll enjoy the video of this interview.

As usual you can find the source listing and used media resources in the video transcript section. Transcript for the video hasn’t been added yet, but will be as soon as possible.