TY - JOUR
T1 - Rapid attribution analysis of the extraordinary heat wave on the Pacific coast of the US and Canada in June 2021
AU - Philip, Sjoukje Y.
AU - Kew, Sarah F.
AU - Van Oldenborgh, Geert Jan
AU - Anslow, Faron S.
AU - Seneviratne, Sonia I.
AU - Vautard, Robert
AU - Coumou, Dim
AU - Ebi, Kristie L.
AU - Arrighi, Julie
AU - Singh, Roop
AU - van Aalst, Maarten
AU - Pereira Marghidan, Carolina
AU - Wehner, Michael
AU - Yang, Wenchang
AU - Li, Sihan
AU - Schumacher, Dominik L.
AU - Hauser, Mathias
AU - Bonnet, Rémy
AU - Luu, Linh N.
AU - Lehner, Flavio
AU - Gillett, Nathan
AU - Tradowsky, Jordis S.
AU - Vecchi, Gabriel A.
AU - Rodell, Chris
AU - Stull, Roland B.
AU - Howard, Rosie
AU - Otto, Friederike E.L.
N1 - Funding Information:
We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6. We thank the climate modelling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies who support CMIP6 and ESGF. We thank Urs Beyerle for downloading and curating the CMIP6 data at ETH Zurich. Flavio Lehner was supported by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the US Department of Energy's Office of Biological and Environmental Research (BER) via National Science Foundation IA 1947282.
Publisher Copyright:
© 2022 Sjoukje Y. Philip et al.
PY - 2022/12/8
Y1 - 2022/12/8
N2 - Towards the end of June 2021, temperature records were broken by several degrees Celsius in several cities in the Pacific Northwest areas of the US and Canada, leading to spikes in sudden deaths and sharp increases in emergency calls and hospital visits for heat-related illnesses. Here we present a multi-model, multi-method attribution analysis to investigate the extent to which human-induced climate change has influenced the probability and intensity of extreme heat waves in this region. Based on observations, modelling and a classical statistical approach, the occurrence of a heat wave defined as the maximum daily temperature (TXx) observed in the area 45-52N, 119-123W, was found to be virtually impossible without human-caused climate change. The observed temperatures were so extreme that they lay far outside the range of historical temperature observations. This makes it hard to state with confidence how rare the event was. Using a statistical analysis that assumes that the heat wave is part of the same distribution as previous heat waves in this region led to a first-order estimation of the event frequency of the order of once in 1000 years under current climate conditions. Using this assumption and combining the results from the analysis of climate models and weather observations, we found that such a heat wave event would be at least 150 times less common without human-induced climate change. Also, this heat wave was about 2 C hotter than a 1-in-1000-year heat wave would have been in 1850-1900, when global mean temperatures were 1.2 C cooler than today. Looking into the future, in a world with 2 C of global warming (0.8 C warmer than today), a 1000-year event would be another degree hotter. Our results provide a strong warning: our rapidly warming climate is bringing us into uncharted territory with significant consequences for health, well-being and livelihoods. Adaptation and mitigation are urgently needed to prepare societies for a very different future.
AB - Towards the end of June 2021, temperature records were broken by several degrees Celsius in several cities in the Pacific Northwest areas of the US and Canada, leading to spikes in sudden deaths and sharp increases in emergency calls and hospital visits for heat-related illnesses. Here we present a multi-model, multi-method attribution analysis to investigate the extent to which human-induced climate change has influenced the probability and intensity of extreme heat waves in this region. Based on observations, modelling and a classical statistical approach, the occurrence of a heat wave defined as the maximum daily temperature (TXx) observed in the area 45-52N, 119-123W, was found to be virtually impossible without human-caused climate change. The observed temperatures were so extreme that they lay far outside the range of historical temperature observations. This makes it hard to state with confidence how rare the event was. Using a statistical analysis that assumes that the heat wave is part of the same distribution as previous heat waves in this region led to a first-order estimation of the event frequency of the order of once in 1000 years under current climate conditions. Using this assumption and combining the results from the analysis of climate models and weather observations, we found that such a heat wave event would be at least 150 times less common without human-induced climate change. Also, this heat wave was about 2 C hotter than a 1-in-1000-year heat wave would have been in 1850-1900, when global mean temperatures were 1.2 C cooler than today. Looking into the future, in a world with 2 C of global warming (0.8 C warmer than today), a 1000-year event would be another degree hotter. Our results provide a strong warning: our rapidly warming climate is bringing us into uncharted territory with significant consequences for health, well-being and livelihoods. Adaptation and mitigation are urgently needed to prepare societies for a very different future.
KW - ITC-ISI-JOURNAL-ARTICLE
KW - ITC-GOLD
UR - http://www.scopus.com/inward/record.url?scp=85145581169&partnerID=8YFLogxK
U2 - 10.5194/esd-13-1689-2022
DO - 10.5194/esd-13-1689-2022
M3 - Article
AN - SCOPUS:85145581169
SN - 2190-4979
VL - 13
SP - 1689
EP - 1713
JO - Earth System Dynamics
JF - Earth System Dynamics
IS - 4
ER -
