Attribution of the Australian bushfire risk to anthropogenic climate change
<p>Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. To answer the question for southeastern Australia, where fires were particularly severe, affe...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-03-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://nhess.copernicus.org/articles/21/941/2021/nhess-21-941-2021.pdf |
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| author | G. J. van Oldenborgh F. Krikken S. Lewis N. J. Leach F. Lehner F. Lehner F. Lehner K. R. Saunders M. van Weele K. Haustein S. Li S. Li D. Wallom S. Sparrow J. Arrighi J. Arrighi R. K. Singh M. K. van Aalst M. K. van Aalst M. K. van Aalst S. Y. Philip R. Vautard F. E. L. Otto |
| author_facet | G. J. van Oldenborgh F. Krikken S. Lewis N. J. Leach F. Lehner F. Lehner F. Lehner K. R. Saunders M. van Weele K. Haustein S. Li S. Li D. Wallom S. Sparrow J. Arrighi J. Arrighi R. K. Singh M. K. van Aalst M. K. van Aalst M. K. van Aalst S. Y. Philip R. Vautard F. E. L. Otto |
| author_sort | G. J. van Oldenborgh |
| collection | DOAJ |
| description | <p>Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. To answer the question for southeastern Australia, where fires were particularly severe, affecting people and ecosystems, we use a physically based index of fire weather, the Fire Weather Index; long-term observations of heat and drought; and 11 large ensembles of state-of-the-art climate models. We find large trends in the Fire Weather Index in the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Reanalysis (ERA5) since 1979 and a smaller but significant increase by at least 30 % in the models. Therefore, we find that climate change has induced a higher weather-induced risk of such an extreme fire season. This trend is mainly driven by the increase of temperature extremes. In agreement with previous analyses we find that heat extremes have become more likely by at least a factor of 2 due to the long-term warming trend. However, current climate models overestimate variability and tend to underestimate the long-term trend in these extremes, so the true change in the likelihood of extreme heat could be larger, suggesting that the attribution of the increased fire weather risk is a conservative estimate. We do not find an attributable trend in either extreme annual drought or the driest month of the fire season, September–February. The observations, however, show a weak drying trend in the annual mean. For the 2019/20 season more than half of the July–December drought was driven by record excursions of the Indian Ocean Dipole and Southern Annular Mode, factors which are included in the analysis here. The study reveals the complexity of the 2019/20 bushfire event, with some but not all drivers showing an imprint of anthropogenic climate change. Finally, the study concludes with a qualitative review of various vulnerability and<span id="page942"/> exposure factors that each play a role, along with the hazard in increasing or decreasing the overall impact of the bushfires.</p> |
| first_indexed | 2024-12-17T06:24:28Z |
| format | Article |
| id | doaj.art-db20f99bb0f1429dadbe31c9f5d580c1 |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-17T06:24:28Z |
| publishDate | 2021-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-db20f99bb0f1429dadbe31c9f5d580c12022-12-21T22:00:20ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812021-03-012194196010.5194/nhess-21-941-2021Attribution of the Australian bushfire risk to anthropogenic climate changeG. J. van Oldenborgh0F. Krikken1S. Lewis2N. J. Leach3F. Lehner4F. Lehner5F. Lehner6K. R. Saunders7M. van Weele8K. Haustein9S. Li10S. Li11D. Wallom12S. Sparrow13J. Arrighi14J. Arrighi15R. K. Singh16M. K. van Aalst17M. K. van Aalst18M. K. van Aalst19S. Y. Philip20R. Vautard21F. E. L. Otto22Royal Netherlands Meteorological Institute (KNMI), De Bilt, the NetherlandsRoyal Netherlands Meteorological Institute (KNMI), De Bilt, the NetherlandsSchool of Science, University of New South Wales, Canberra, ACT, AustraliaAtmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, UKDepartment of Earth and Atmospheric Sciences, Cornell University, Ithaca, USAClimate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, USAInstitute for Atmospheric and Climate Science, ETH Zürich, Zurich, SwitzerlandDelft Institute of Applied Mathematics, Delft University of Technology, Delft, the NetherlandsRoyal Netherlands Meteorological Institute (KNMI), De Bilt, the NetherlandsEnvironmental Change Institute, University of Oxford, Oxford, UKEnvironmental Change Institute, University of Oxford, Oxford, UKOxford e-Research Centre, University of Oxford, Oxford, UKOxford e-Research Centre, University of Oxford, Oxford, UKOxford e-Research Centre, University of Oxford, Oxford, UKRed Cross Red Crescent Climate Centre, the Hague, the NetherlandsGlobal Disaster Preparedness Center, Washington, DC, USARed Cross Red Crescent Climate Centre, the Hague, the NetherlandsRed Cross Red Crescent Climate Centre, the Hague, the NetherlandsFaculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, the NetherlandsInternational Research Institute for Climate and Society, Columbia University, New York, USARoyal Netherlands Meteorological Institute (KNMI), De Bilt, the NetherlandsInstitut Pierre-Simon Laplace, Gif-sur-Yvette, FranceEnvironmental Change Institute, University of Oxford, Oxford, UK<p>Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. To answer the question for southeastern Australia, where fires were particularly severe, affecting people and ecosystems, we use a physically based index of fire weather, the Fire Weather Index; long-term observations of heat and drought; and 11 large ensembles of state-of-the-art climate models. We find large trends in the Fire Weather Index in the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Reanalysis (ERA5) since 1979 and a smaller but significant increase by at least 30 % in the models. Therefore, we find that climate change has induced a higher weather-induced risk of such an extreme fire season. This trend is mainly driven by the increase of temperature extremes. In agreement with previous analyses we find that heat extremes have become more likely by at least a factor of 2 due to the long-term warming trend. However, current climate models overestimate variability and tend to underestimate the long-term trend in these extremes, so the true change in the likelihood of extreme heat could be larger, suggesting that the attribution of the increased fire weather risk is a conservative estimate. We do not find an attributable trend in either extreme annual drought or the driest month of the fire season, September–February. The observations, however, show a weak drying trend in the annual mean. For the 2019/20 season more than half of the July–December drought was driven by record excursions of the Indian Ocean Dipole and Southern Annular Mode, factors which are included in the analysis here. The study reveals the complexity of the 2019/20 bushfire event, with some but not all drivers showing an imprint of anthropogenic climate change. Finally, the study concludes with a qualitative review of various vulnerability and<span id="page942"/> exposure factors that each play a role, along with the hazard in increasing or decreasing the overall impact of the bushfires.</p>https://nhess.copernicus.org/articles/21/941/2021/nhess-21-941-2021.pdf |
| spellingShingle | G. J. van Oldenborgh F. Krikken S. Lewis N. J. Leach F. Lehner F. Lehner F. Lehner K. R. Saunders M. van Weele K. Haustein S. Li S. Li D. Wallom S. Sparrow J. Arrighi J. Arrighi R. K. Singh M. K. van Aalst M. K. van Aalst M. K. van Aalst S. Y. Philip R. Vautard F. E. L. Otto Attribution of the Australian bushfire risk to anthropogenic climate change Natural Hazards and Earth System Sciences |
| title | Attribution of the Australian bushfire risk to anthropogenic climate change |
| title_full | Attribution of the Australian bushfire risk to anthropogenic climate change |
| title_fullStr | Attribution of the Australian bushfire risk to anthropogenic climate change |
| title_full_unstemmed | Attribution of the Australian bushfire risk to anthropogenic climate change |
| title_short | Attribution of the Australian bushfire risk to anthropogenic climate change |
| title_sort | attribution of the australian bushfire risk to anthropogenic climate change |
| url | https://nhess.copernicus.org/articles/21/941/2021/nhess-21-941-2021.pdf |
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