Australasian Science Magazine

By Stephen Luntz

A study of the abstracts of 12,000 peer reviewed papers on climate change has found that 97% of those expressing a position on the causes of climate change attributed it to human activity.

The papers were assessed by volunteers collected via the website skepticalscience.com, which is run by Mr John Cook of the University of Queensland’s Global Change Institute. Two-thirds of the abstracts did not refer to the causes of climate change, but of those that did just 2% rejected human activities as the main cause while 1% expressed uncertainty.

Cook also contacted 8000 authors to ask if they thought their paper as a whole shed light on the attribution of warming trends. Of the 1200 who responded, 65% said their paper took a position, but again only 3% said this position involved a rejection of the consensus view that climate change is human-induced. “The respondents appear to be fairly representative of the authors,” Cook says.

The papers examined were published between 1991 and 2011. The consensus has strengthened over that time, with the number of papers rejecting human involvement in climate change broadly stable while publications on the topic have risen substantially in recent years.

The fact that the majority of abstracts did not express an opinion on human involvement is not surprising, says Cook. The study was done on all papers that mentioned “global climate change” or “global warming”, and he thinks many looking at effects would not have “wanted to waste valuable space in their abstract” discussing attribution.

The paper achieved global fame when US President Barak Obama tweeted a reference to it to his 31 million Twitter followers. Cook is not sure what effect this had on downloads, but it certainly increased the media inquiries he received.

Inevitably Cook has suffered attacks from those who side with the 3%. “A blog post compared one small subset of those who endorsed the consensus with the whole body of those who rejected it and claimed the numbers were equal, but this was gross cherry-picking,” he says.

Cook has created a checking mechanism where anyone visiting skepticalscience.com can receive a random ten abstracts and place them in one of seven categories ranging from explicit endorsement to explicit rejection of human contribution to climate change.

Cook’s paper was published in Environmental Research Letters, and crowdsourced fundraising enabled open access to it.

“There is a gaping chasm between the actual consensus and the public perception,” Cook says. “This is significant because when people understand that scientists agree on global warming they’re more likely to support policies that take action on it.”