Scientists “overwhelmingly” agree that global warming is man-made, with 97% saying humans are to blame for climate change.

Research published by the Institute of Physics (IoP) looked at almost 12,000 peer-reviewed articles on global warming from the last 20 years.

The researchers found that 66.4% of papers had no opinion on global warming, 32.6% endorsed anthropogenic (man-made) global warming (AGW), while 0.7% rejected AGW.

Of those which expressed an opinion on climatic global warming, over 97% of papers agreed that humans are causing climate change.

Lead author John Cook, from the University of Queensland, said the findings show a consensus among scientists that climate change is being caused by humans despite public perception to the contrary.

In 2012, research by Yale University found that just 54% of Americans believe global warming is being caused by human activities.

The IoP study found that papers which expressed an opinion on climate change endorsed the consensus that humans cause global warming, and that this opinion increased over time.

“Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research.”

Campaigns designed to confuse public

It said there is a public perception that climate change scientists disagree on the fundamental cause of global warming but that this is not the case.

The paper said the perception of scientific consensus on AGW is essential for support for climate change policy and that this perception is being magnified by media reports, where climate change sceptics are given a greater voice and create the impression that the scientific community is debating the issue.

“Contributing to this ‘consensus gap’ are campaigns designed to confuse the public about the level of agreement among climate scientists,” the authors said.

“In 1991, Western Fuels Association conducted a $510,000 campaign whose primary goal was to ‘reposition global warming as theory (not fact)’. A key strategy involved constructing the impression of active scientific debate using dissenting scientists as spokesmen.

“The situation is exacerbated by media treatment of the climate issue, where the normative practice of providing opposing sides with equal attention has allowed a vocal minority to have their views amplified.

“The number of papers rejecting AGW is a miniscule proportion of the published research, with the percentage slightly decreasing over time. Among papers expressing a position on AGW, an overwhelming percentage endorses the scientific consensus on AGW.”