As the UN IPCC delivered its recent special report on the state of global climate science, Dimitri Zenghelis et al. warn that although the promise of limiting warming to 1.5°C is unplausible, there is the possibility that early action can, cost-effectively, prevent a three or four degree increase.
The United Nations Intergovernmental Panel on Climate Change (IPCC) report (2021) shows that there is no scenario – not even the rosiest, most aggressive emissions reduction pathway – for which the best estimate of temperature rise is held below 1.5°C for the century.
In a short analysis written with colleagues John Llewellyn and Preston Llewellyn, Dimitri Zenghelis draws on work undertaken at the Bennet Institute for Public Policy to argue that meeting the two degree temperature stabilisation target modelled in the IPCC report will be challenging. On current trends, a rise of three or even four degrees seems more probable.
The authors present two important conditionally optimistic scenarios that stand a good chance of limiting temperature increases to less dangerous levels. Attaining these will require clear, credible and early action to steer innovation and finance clean investment in physical, human, intangible and natural capital.
They show why this window of opportunity is rapidly closing.