Climate scientists agree: Global warming is man-made

Kerry Gordon

5 June 2013

A recent analysis of over 12 000 research papers shows that the overwhelming majority of climate scientists agree that climate change is influenced by human activity.

The paper, published last month by John Cook of Skeptical Science and the Consensus Group, looked at whether there was an agreement among scientists that climate change is man-made. In March 2012, they searched a database of research articles published between 1991 and 2012 for the terms ‘global warming’ or ‘global climate change’. They surveyed 12,465 articles, of which 4,014 (32%), with a total of 10,188 authors, mentioned human-related causes for climate change, called anthropogenic global warming. Of these articles, 97% supported the consensus of anthropogenic global warming.

What about the 68% of articles that didn’t mention anthropogenic global warming? The authors explain that in the majority of these papers, the consensus is so clear within the climate science community that there is no need to reiterate it - in the same way that HIV research articles don’t state that HIV causes AIDS, because the link has been well and truly established. To show this, Cook contacted the authors of the papers in their survey and asked them to rate their own papers according to whether anthropogenic global warming was endorsed in the article; more than half (62%) rated papers as agreeing with this view.

What is encouraging about this research is that it is based on a new model. Volunteers helped with the survey of articles, funding was crowd-sourced and the researchers made their paper freely accessible so that the articles could be independently surveyed. The paper was published in a peer-reviewed open access journal, allowing anyone to read it and even to access the database of articles that were used in the study. In a field that constantly comes under heavy fire, this transparency is very encouraging and also means that the study is available for careful scrutiny.


Source: The Consensus Project

Despite this staggering evidence that climate scientists agree that current climate change is influenced by human activity, Cook’s paper is receiving criticism, albeit not from the scientific community at large, but from groups and individuals that question whether anthropogenic global warming exists.

For there to be any drive for change, we need more support for climate change policies. But governments are dragging their heels - by what is thought to be a deliberate campaign by climate change denialists - mainly by swaying public opinion through suggesting that there is a vast disagreement among scientists that climate change or global warming are happening and that it is predominantly man made. Public polls in the US show that only 45% of Americans think that there is agreement in the scientific community about the cause of climate change.

Climate change threatens human development, with many African countries being particularly at risk. With small regional changes in temperature due to global warming, we will likely have increased water scarcity, more extreme weather and rising sea levels, threatening our food and water supplies and potentially leading to substantial population displacement. With a large portion of South Africa’s population living in poverty we have very little leeway with resources; our country’s poor are likely to be the most heavily affected.

Placing the focus on whether there is a consensus among climate scientists erodes the public’s understanding of anthropogenic global warming, despite the clear scientific data to support it. As is evident from Cook’s paper, only a tiny percentage of scientists deny human activity in climate change, but it is their voices that are mainly heard in the press. Similarly, our South African media gives disproportionate prominence to uninformed climate change deniers like Ivo Vegter and Andrew Kenny, who mask their ignorance by entertaining their readership with wit rather than sound facts and arguments.

Kerry Gordon has a doctorate in biochemistry from the University of Cape Town. Her main research interest was the 3-D shape of proteins and their function, ranging from ones involved in blood pressure regulation to HIV proteins that enable transmission. She is currently a scientific editor for a medical publisher. You can follow her on Twitter: @Kerry_Gordon