June 28, 2022

expert reaction to review of extreme weather and attribution to climate change

A study published in Environmental Research: Climate looks at the extreme weather impacts of climate change

This Roundup accompanied an SMC Briefing.

Prof Tim Palmer, Royal Society Research Professor, University of Oxford, said

“Attribution analyses for extreme weather events are much in demand. The authors review the current state of the art and highlight some areas where we need to advance our understanding. On this, they miss one very important area: improving the reliability of the very climate models used to do these attribution studies. As we very recently discussed in Nature Climate Change¹, current climate models struggle to represent precipitation and related extreme events. This undermines attempts to attribute extreme weather events quantitatively. The solution requires new international partnerships to allow km-scale global climate models to be developed and run on dedicated exascale computers – a kind of ‘Climate CERN’.”

¹ https://www.nature.com/articles/s41558-022-01384-8

Two quotes provided by the Spanish SMC:

Ernesto Rodríguez Camino, senior State meteorologist, head of Climate Assessment and Modelling at the Spanish State Meteorological Agency (AEMET) and expert in the generation of regionalised climate change scenarios for Spain, said:

“Dr Friederike Otto is a pioneer in near-real-time attribution studies of extreme weather events. Attribution studies determine the role of climate change in the frequency and intensity of extreme weather events, such as heat waves or tropical cyclones. This requires two essential sources of information. On the one hand, numerical simulations capable of reproducing the observed extreme event and, on the other hand, observations that allow the different aspects of the event to be characterised.

“Limited access to observations has limited and continues to limit further attribution studies to prepare affected sectors for increasingly frequent and intense weather extremes, a consequence of ongoing anthropogenic climate change.

“This paper comprehensively reviews the role of anthropogenic climate change in extreme weather and climate events. While the attribution of increased frequency, intensity and duration of heatwaves to climate change has high confidence in many regions of the world (including the Mediterranean), the attribution of intense precipitation events (and often associated floods) to climate change is more doubtful in most cases.

“For other types of events, such as droughts, forest fires or tropical cyclones, there is even less confidence in their attribution to climate change and more studies are needed in different regions of the globe.”

María José Sanz, scientific director of BC3 Basque Centre for Climate Change, said:

“This is the most comprehensive review to date of the understanding of the influences of climate change on five types of extreme weather events: extreme temperatures, heavy rainfall, droughts, forest fires and tropical cyclones. This extends both the record of extreme weather impacts worldwide and the coverage of attribution studies across different events and regions, in particular the global south. The work represents an improvement over the analyses conducted in the Sixth Assessment Report of the Governmental Panel on Climate Change.

“It indicates that the attribution of some of these events to a greater or lesser extent to climate change has so far been underestimated.”

‘Extreme weather impacts of climate change: an attribution perspective’ by Ben Clarke et al. was published in Environmental Research: Climate at 8am UK TIME on Tuesday 28 June 2022.

Declared interests

Prof Tim Palmer: “none to declare.”

For all other experts, no reply to our request for DOIs was received.