Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere.

Autor:	Liu P; School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. pengfei.liu@eas.gatech.edu.; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA., Kaplan JO; Department of Earth Sciences, The University of Hong Kong, Hong Kong, China., Mickley LJ; School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA., Li Y; School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.; Department of Environmental Science, Baylor University, Waco, TX 76798, USA., Chellman NJ; Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USA., Arienzo MM; Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USA., Kodros JK; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80521, USA., Pierce JR; Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, USA., Sigl M; Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland.; Climate and Environmental Physics, University of Bern, 3012 Bern, Switzerland., Freitag J; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany., Mulvaney R; British Antarctic Survey, Cambridge, UK., Curran MAJ; Australian Antarctic Division and Antarctic Climate and Ecosystem Cooperative Research Centre, Hobart, Tasmania, Australia., McConnell JR; Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USA.; Clare Hall, University of Cambridge, Cambridge CB3 9AL, UK.
Jazyk:	angličtina
Zdroj:	Science advances [Sci Adv] 2021 May 28; Vol. 7 (22). Date of Electronic Publication: 2021 May 28 (Print Publication: 2021).
DOI:	10.1126/sciadv.abc1379
Abstrakt:	Fire plays a pivotal role in shaping terrestrial ecosystems and the chemical composition of the atmosphere and thus influences Earth's climate. The trend and magnitude of fire activity over the past few centuries are controversial, which hinders understanding of preindustrial to present-day aerosol radiative forcing. Here, we present evidence from records of 14 Antarctic ice cores and 1 central Andean ice core, suggesting that historical fire activity in the Southern Hemisphere (SH) exceeded present-day levels. To understand this observation, we use a global fire model to show that overall SH fire emissions could have declined by 30% over the 20th century, possibly because of the rapid expansion of land use for agriculture and animal production in middle to high latitudes. Radiative forcing calculations suggest that the decreasing trend in SH fire emissions over the past century largely compensates for the cooling effect of increasing aerosols from fossil fuel and biofuel sources. (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)
Databáze:	MEDLINE
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