Other questions revealed that 93% of those polled agreed that carbon-dioxide-emitting infrastructure will continue to expand if uninterrupted by government policy, while 68% agreed that even under favourable assumptions, abundant natural gas will have little impact on greenhouse emissions. (In September 2014, a paper by Shearer et al in Environmental Research Letters (ERL) indicated that without a climate policy, the abundant use of natural gas – a lower carbon fuel than coal – could actually boost electricity consumption.)

“This round of results suggests that while there is debate as to which indicators of planetary health are best, there is much more agreement on the necessary actions and the implications of inaction,” said Peter Kriss, director of research for Vision Prize.

“Here’s the dilemma for investors and policymakers,” Kriss added. “It is known that carbon dioxide emissions cause the Earth to warm. If the strong consensus of our scientific experts is correct, then most of the coal, oil and gas reserves of publicly listed companies are ‘unburnable’. (See, for example, CarbonTracker.) The existential questions for investors and policymakers become: ‘which countries and companies, if any, will give up burning fossil fuels, and when?’”

In their comment piece, Victor and Kennel also argued that the world should ditch the 2 °C warming goal and instead track “an array of planetary vital signs – such as changes in the ocean heat content – that are better rooted in the scientific understanding of climate drivers and risks”.

This proposal proved controversial, with Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, Germany, commenting at RealClimate that 2 °C is the obvious choice for a global goal because “it is a single metric that is (a) closely linked to radiative forcing (i.e. the main anthropogenic interference in the climate system) and (b) most impacts and risks depend on it”.

The opinions of climate scientists in the Vision Prize poll were also split; 48% considered that average global temperature is a good indicator of planetary health whilst 41% believed that it isn’t. There was no clear outcome as to which measure would be better – 56% of poll participants felt that greenhouse gas concentrations were a better indicator than average global temperature and 53% thought that ocean heat content would be an improvement.

• Vision Prize asks respondents for their answer to each question as well as how they believe their peers will react. Poll participants are pre-screened to ensure they have relevant expertise. Head to Vision Prize for a full breakdown of the results.

• This article was corrected on 26th February 2015 to alter the phrase "41% considered that average global temperature is a good indicator of planetary health whilst 48% believed that it isn’t" to the correct version "48% considered that average global temperature is a good indicator of planetary health whilst 41% believed that it isn’t".

Related links

• Climate policy: Ditch the 2 °C warming goal
• Limiting global warming to 2 °C – why Victor and Kennel are wrong
• Vision Prize