Appendix B: the 97% scientific consensus on Global warming*
97% of climate experts agree humans are causing global warming
Let’s pause for a while to examine that 97%. In 2016, a number of noted scientists qualified in this field[1] published a paper entitled Consensus on consensus: a synthesis of consensus estimates on human-caused global warming[2], the two key conclusions from which are that:
- Depending on exactly how you measure the expert consensus, it’s somewhere between 90% and 100% that agree humans are responsible for climate change, with most of the co-authors’ studies finding 97% consensus among publishing climate scientists.
- The greater the climate expertise among those surveyed, the higher the consensus on human-caused global warming, thus:
In his commentary on the paper[3], John Cook makes a couple of telling points. The first is that science achieves a consensus when scientists stop arguing, and in answering the question: “what would happen if we put a load more CO2 in the atmosphere?” “There may be many hypotheses about cause and effect. Over a period of time, each idea is tested and retested, because the processes of the scientific method are rigorous in the extreme. But the testing period must come to an end”.
The second is that consensus in science is different from a political one. There is no vote. Scientists just give up arguing because the sheer weight of consistent evidence is too compelling, the tide too strong to swim against any longer, and in the scientific field of climate studies – which is informed by many different disciplines – the consensus is demonstrated by the number of scientists who have stopped arguing about what is causing climate change – and that’s nearly all of them.
Thirdly, expert consensus is a powerful thing. People know we don’t have the time or capacity to learn about everything, and so we frequently defer to the conclusions of experts. It’s why we visit doctors when we’re ill and lawyers when we need legal advice. The same is true of climate change: most people defer to the expert consensus of climate scientists.
Yet at the same time, this leaves those very same climate scientists in somewhat of a quandary, well described by Andrew Glikson, an earth and climate scientist at the ANU. They find themselves in a situation similar to medical doctors who need to break the news of a grave diagnosis. "How do they tell people that the current spate of cyclones, devastating islands from the Caribbean to the Philippines, or the flooding of coastal regions and river valleys from Mozambique to Kerala, Pakistan and Townsville, can only intensify in a rapidly warming world?
"How do scientists tell the people that their children are growing into a world where survival under a mean temperatures 2C above pre-industrial levels may be painful, and in some parts of the world impossible, let alone under 4C rise projected by the IPCC? The Cassandra syndrome is alive and well. (Apollo gave Cassandra the gift of prophecy but, humiliated by her unrequited love, he also placed a curse on her, ensuring no one would believe her warnings.)
"Throughout history, messengers of bad news have been rebuked or worse. Nowadays, many scientists are reticent to publish their climate change projections. Given the daunting scenarios they confront, many find it difficult to talk about it, even among friends and family". Their collective message about the impending catastrophe facing our civilisation is drowned out by short term distractions of far less consequence.
* Header source: "Do 97% of climate scientist really agree?" Youtube video: :https://www.youtube.com/watch?v=SSrjAXK5pGw
[1] John Cook, Naomi Oreskes, Peter T Doran, William R L Anderegg, Bart Verheggen, Ed W Maibach, J Stuart Carlton, Stephan Lewandowsky, Andrew G Skuce, Sarah A Green. There qualifications may be found on the paper., Dana Nuccitelli3, Peter Jacobs9, Mark Richardson14, Bärbel Winkler3, Rob Painting3 and Ken Rice15
[2] The paper may be found at http://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002 It was published on13 April 2016 • © 2016 IOP Publishing Ltd Environmental Research Letters, Volume 11, Number 4
[3] “Getting sceptical about global warming scepticism” at https://skepticalscience.com/global-warming-scientific-consensus.htm
Next
The second is that consensus in science is different from a political one. There is no vote. Scientists just give up arguing because the sheer weight of consistent evidence is too compelling, the tide too strong to swim against any longer, and in the scientific field of climate studies – which is informed by many different disciplines – the consensus is demonstrated by the number of scientists who have stopped arguing about what is causing climate change – and that’s nearly all of them.
Thirdly, expert consensus is a powerful thing. People know we don’t have the time or capacity to learn about everything, and so we frequently defer to the conclusions of experts. It’s why we visit doctors when we’re ill and lawyers when we need legal advice. The same is true of climate change: most people defer to the expert consensus of climate scientists.
Yet at the same time, this leaves those very same climate scientists in somewhat of a quandary, well described by Andrew Glikson, an earth and climate scientist at the ANU. They find themselves in a situation similar to medical doctors who need to break the news of a grave diagnosis. "How do they tell people that the current spate of cyclones, devastating islands from the Caribbean to the Philippines, or the flooding of coastal regions and river valleys from Mozambique to Kerala, Pakistan and Townsville, can only intensify in a rapidly warming world?
"How do scientists tell the people that their children are growing into a world where survival under a mean temperatures 2C above pre-industrial levels may be painful, and in some parts of the world impossible, let alone under 4C rise projected by the IPCC? The Cassandra syndrome is alive and well. (Apollo gave Cassandra the gift of prophecy but, humiliated by her unrequited love, he also placed a curse on her, ensuring no one would believe her warnings.)
"Throughout history, messengers of bad news have been rebuked or worse. Nowadays, many scientists are reticent to publish their climate change projections. Given the daunting scenarios they confront, many find it difficult to talk about it, even among friends and family". Their collective message about the impending catastrophe facing our civilisation is drowned out by short term distractions of far less consequence.
* Header source: "Do 97% of climate scientist really agree?" Youtube video: :https://www.youtube.com/watch?v=SSrjAXK5pGw
[1] John Cook, Naomi Oreskes, Peter T Doran, William R L Anderegg, Bart Verheggen, Ed W Maibach, J Stuart Carlton, Stephan Lewandowsky, Andrew G Skuce, Sarah A Green. There qualifications may be found on the paper., Dana Nuccitelli3, Peter Jacobs9, Mark Richardson14, Bärbel Winkler3, Rob Painting3 and Ken Rice15
[2] The paper may be found at http://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002 It was published on13 April 2016 • © 2016 IOP Publishing Ltd Environmental Research Letters, Volume 11, Number 4
[3] “Getting sceptical about global warming scepticism” at https://skepticalscience.com/global-warming-scientific-consensus.htm
Next