Heatwaves are an issue now and moving forward.
Yann Quicalle, postdoctoral researcher at ETH Zurich, looks at the reasons behind them.
Dr Yann Quilcaille is a climate scientist, who works to bridge the gap between climate and economic modelling. Thanks to a dual background in climate science and economics of sustainable development, he gained a deep knowledge of this interface. Dr Yann Quilcaille has conducted his PhD in France, worked as a research scholar in Austria and pursued as a postdoctoral researcher in Switzerland. His research is focused on climate extremes (e.g. heatwaves, wildfires and droughts) and climate emulators. Recently, Dr Yann Quilcaille extended his work to climate attribution.
How Fossil Fuel Companies Have Contributed to Heatwaves
Thanks to more and more detailed observations and a better understanding of the Earth system, scientists have already established that our climate is changing at an alarming rate, mostly due to the combustion of fossil fuels, and that it causes extreme weather events to become more frequent and more intense. Among other methods, attribution studies analyze whether and how much climate change influenced a specific extreme weather event, for instance the Pacific Northwest heatwave in 2021. Recently, my coauthors and I have filled in two scientific gaps in climate attribution.
Instead of analyzing a single event, we have applied a well established attribution framework to each one of the 213 heatwaves reported in a disaster database, meaning that each had significant societal impacts. This enhanced coverage shows that every analyzed heatwave have become more intense and more likely due to climate change. The heatwaves over 2000-2009 have become 20 times more likely compared to pre-industrial levels, but over 2010-2019, this influence rises to 200 times. Besides, about one quarter of the heatwaves were made so much more likely that they would have been virtually impossible without climate change.
Then, we extended the attribution to the sources. Knowing the emissions from 180 fossil fuels and cement companies, we disentangled their contributions to global warming and each heatwave. While some entities are bigger than others, we prove that each substantially contributes to heatwaves. Even the sole emissions of relatively minor players can enable the occurrence of virtually impossible events.
While we aimed at filling in scientific gaps, we were aware of the implications. Such scientific evidence informs about legal responsibilities, but there are other aspects. For instance, blaming the producers or the consumers may depend on the perception on the manipulation of markets through lobbying and misinformation.
Read More:
[Nature] – Systematic attribution of heatwaves to the emissions of carbon majors
