MIL-OSI UK: expert reaction to research on keeping warming below 1.5C

Source: United Kingdom – Executive Government & Departments

Reactions to research published in Nature Communications that claims keeping global temperature increases below 1.5°C remains possible with immediate emission reduction across all sectors.

Dr Phillip Williamson, Honorary Reader at the University of East Anglia (UEA), said:

The analysis by Christopher Smith and his colleagues is welcome.  Climate change policy does need some good news, and their message is that we’re not (quite) doomed yet.  If from now on, the greenhouse gas-emitting power plants, factories, cars, ships and planes are replaced by non-polluting alternatives as they reach the end of their lifetimes, then the threshold of 1.5C warming might not be crossed. 

“Yet that is a very big ‘if’.  The authors are clear in their paper that ‘we do not seek to assess the practical feasibility of this transition’; they also assume that land-use related emissions (currently nearly a fifth of the total) magically drop to zero in 2020, and there are no significant amplifying climate feedbacks, such as increased forest fires or melting permafrost.  According to Smith’s paper, there is then a 2 to 1 probability of keeping warming below 1.5C.  

“But the optimism should not be overstated.  The paper’s title is potentially misleading in that regard: whilst current infrastructure may not take us over the top, there is unfortunately insufficient evidence to say that it definitely will not happen.  Therefore this analysis is not an excuse for inaction, but further incentive to make the necessary changes, with the requirement for nothing new that burns coal, oil or gas.”

Prof Mark Maslin, Professor of Climatology at UCL, said:

Smith and colleagues have produced a detail study of potential global warming based on when and how we reduced global greenhouse emissions.  This study provides optimism for the future if we act now.  The research shows we can keep global warming to below 1.5˚C even with our current fossil fuel infrastructure, if we ensure it is replaced with renewable sources at the end of its life time and we aggressively cut global emissions starting this year.   Each year we fail to cut global emissions will make it more and more unlikely that we can keep global warming below 1.5˚C. If emission reductions do not start until 2030 then it is all but impossible to keep below the 1.5˚C threshold recently recommended by the IPCC.”

Prof Dave Reay, Chair in Carbon Management at the University of Edinburgh, said:

“An insightful and important look at the chances of holding average global temperature increase to 1.5C, and how delays in weaning our world off fossil fuels could well scupper these chances.

“Whether it’s drilling a new gas well, keeping an old coal power station open, or even buying a diesel car, the choices we make today will largely determine the climate pathways of tomorrow. There’s plenty to give hope here – retiring all high-carbon infrastructure as it reaches the end of its planned life can avoid this ‘carbon lock-in’ and give us a better-than-evens shot at 1.5C.

“The risks of climate curve balls, like warming-induced faltering of the land and ocean carbon sinks or huge belches of Arctic methane, are still out there, but the message of this new study is loud and clear: act now or see the last chance for a safer climate future ebb away.”

Current fossil fuel infrastructure does not yet commit us to 1.5 °C warming’ by Christopher J. Smith et al. was published in Nature Communications at 4pm UK TIME on Tuesday 15 January 2018.

Declared interests

Dr Williamson is an Honorary Reader at the University of East Anglia, employed by the Natural Environment Research Council (NERC, part of UKRI).  He is the Science Coordinator of the NERC-led Greenhouse Gas Removal programme.

Prof Maslin: I have no interests or associations with this study or its finding

Prof Reay: No interest declared.