November 22, 2019

expert reaction to paper reassessing the progress and mitigation of climate change

A study, published in Environmental Research Letters, reports on the progress of climate change and calls for more balanced discussion of possible mitigation tactics. 

Dr Chris Brierley, Co-Director of the UCL Environment Institute and Lecturer in Climate Modelling, University College London (UCL), said:

“I appreciate the effort to provide a positive of the message – and agree that I’ve seen many examples of where the costs of moving to greener, more sustainable technology and behaviours have been over-estimated. I would note, that despite the mitigation costs and progress highlighted in the press release, that atmospheric CO2 levels are increasing at an accelerating rate.”

Prof Mike Lockwood FRS, Professor of Space Environment Physics, University of Reading, said:

“I strongly welcome this report that, whilst stressing the consensus view that projections for the evolution of the planet’s climate are increasingly worrying, rightly points out that that there are steps we can take.  As the predictions made decades ago increasingly turn to realities, there has been a noticable shift away from denial of the science to denial of its full consequences with accusations of “climate catastrophizing”.  This report makes the valid point that we can avoid the worst-case scenarios  – but we do need to act and not just talk about or promise action at a later date.  And we need to act in the most effective ways that mitigate the most serious risks and the science can help identify what they are.”

Prof Sir John Beddington, Professor of Natural Resources Management and Senior Adviser to the Oxford Martin School, Oxford Martin School, University of Oxford, said:

“This paper rightly emphasises that large-scale, low-cost opportunities for mitigation exist in the form of energy efficiency measures and that a systemic approach can help understand them and model them better.  Similar drivers for innovation also apply in areas like carbon dioxide removal and utilisation, which can often be part of the same cascade of mitigation options for an emitting industry.   Whole-system optimization could be applied across all of these domains.”

Prof Rowan Sutton, Director, National Centre for Atmospheric Science, University of Reading, said:

“In problems of risk assessment special attention must always be paid to worst case scenarios. When buying house insurance we ask what’s the worst that could happen, and when considering the future of our home planet we must ask the same.   Sadly we cannot purchase insurance for a replacement Earth, but this new study highlights the huge potential to reduce significantly the future impacts and risks caused by climate change.  The urgency of these actions cannot be overstated.”

Dr Paul Brockway, University Academic Fellow, School of Earth and Environment, University of Leeds, said:

“The authors say “Reduced primary energy intensity, plus an increased share of decarbonized final supply, have lately matched the sustained 3.4 per cent per year that IPCC AR5 found necessary for a 2 C˚ trajectory. Together they are only half of, but trending toward, the sustained 6.7 per cent per year needed for 1.5 C˚.”.  However, the suggested rosy picture of energy efficiency (via large current reductions in energy intensity) is not supported by the International Energy Agency’s Energy Efficiency data.  The IEA data says that in 2018 the global primary energy intensity reduced by 1.2%/year.  Fatih Birol, executive director of the IEA said earlier this year “The historic slowdown in energy efficiency in 2018 – the lowest rate of improvement since the start of the decade – calls for bold action by policy makers and investors”.

“Secondly, the rosy outlook is not entirely supported by the author’s own data: from Figure 1 and 2 in the paper they suggest there is a ‘pattern breaking’ trend post 2010 in primary energy intensity (i.e. primary energy used to produce a dollar of global GDP_PPP).  However, that does not take into account the trend post 2015, which is returning the long-term trend.

“What are the implications of this study?  The authors say “The evidence is now clear that climate mitigations, particularly on the demand side, well in excess of those traditionally modelled will make sense, make money, and create large co-benefits”.  The data suggests a return to the long-term trend of energy intensity reductions of ~-1.5% per year – an improvement of -1.5% in energy intensity is 1.5% relative reduction in energy use versus GDP from one year to the next.  Or put it the other way: it means that GDP has grown 1.5% faster than energy use in that year.  It doesn’t necessarily mean that energy decreases, just that GDP grows faster than energy use.  The implication is that continued focus on device-level efficiency (i.e. more efficient cars, boilers) may not deliver the scale of global energy reduction required.  Different actions are needed, focussing on sufficiency rather than efficiency: we should step up efforts on other demand-sided interventions, such as economy-wide deep housing retrofits, switching to less energy intensive transport, including curtailing growth in aviation.”

* ‘Recalibrating climate prospects’ by Lovins et al. was published in Environmental Research Letters at 00:01 UK time on Friday 22 November 2019.

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