The studies endorsing the scientific consensus about the anthropogenic origins of climate change also include sceptical analyses

A video that has more than 178,500 plays on YouTube and is available on other podcast platforms such as iVoox has stated that one of the studies endorsing the nearly unanimous consensus that climate change is man-made is misleading because its sample only includes studies that come to the same conclusion, not sceptical ones.

This statement is MISLEADING. The study that the moderator is referring to makes a selection of all the available scientifically valid studies on the topic taken from the Web of Science, a database of scientific studies, which includes the most relevant journals, with different conclusions, i.e. ones that indicate that climate change has an anthropogenic origin and ones that do not, as Mark Lynas explains to Verificat. Lynas is Climate Lead at Alliance for Science, a Boyce Thompson Institute initiative (Cornell University, USA), and the main author of the study in question. The expert insists that “the objective of the study was precisely to find out how many sceptical studies there are in all the scientific literature on climate change”. Of a total of 88,000 studies, they found 28 studies with sceptical conclusions.

In any case, it is not the only study that reaches this conclusion. Other previous studies, published in 2009, 2010 and 2013, also indicated that the vast majority of the publications on the origin of climate change suggest that its cause is anthropogenic. Currently, the position of the IPCC – i.e. the Intergovernmental Panel on Climate Change, the leading scientific body in the assessment of climate change – indicates that the role of humankind is “unequivocal”.

“I subscribe to National Geographic and the other day I got an email from them saying that ‘there is now a consensus: 99.9% of studies confirm that climate change is man-made […] Of course they had picked a number of studies… they’re not saying ‘all the studies on climate change published to date’. [It’s as though] they want you to reach whatever conclusion and they pick the studies with the conclusion that you defend, and then they say ‘there is now a consensus’”

A quick Google search for the study, which happens to be open access, shows that the researchers selected “a randomized subset […] from a dataset of 88,125 climate-related papers published since 2012, when this question was last addressed comprehensively”, according to Lynas, the main author of the publication. “We took a sample of 3,000 because combing through 88,000 studies one by one is too much work; a sample allows us to make several statistical evaluations of the probable frequency of sceptical articles”, he explains.

Of the 3,000 papers, only four indicated that the origin of climate change is natural or, at least, not man-made. And then, among the 88,000 studies, they purposely looked for sceptical scientific studies and only found 28. The researchers concluded that the scientific consensus on the current man-made climate change exceeds 99% in the peer-reviewed scientific literature, i.e. studies that have been rigorously reviewed by independent experts. Therefore, the experts did take the sceptical studies into account, but they are a minority of the total number of publications on the topic.

One study on its own is not enough

That said, even if a study is rigorous and has been reviewed by peers, the conclusions of a single study are not enough to firmly demonstrate the scientific consensus on a subject. In the case of the anthropogenic origin of climate change, several studies have been published that yield similar numbers (here is one from 2009, another from 2010, and another from 2013), which have helped to ensure there is such a consensus.

“Those three studies have used independent methods to arrive at a consistent conclusion”, John Cook, researcher at Monash University’s Climate Change Communication Research Hub (Australia) and main author of the study published in 2013, tells Verificat.

Even the IPCC indicated in its last report for policymakers that the role of human beings in this climate change is “unequivocal”. Along with the analysis, they published a graph, the first one that appears in the report, showing what would have happened to temperatures if humans would not have intervened. The result is clear: the influence of humankind is an outdated debate within the scientific community.