The Paris Agreement objectives will likely halt future declines of emperor penguins

• Published in: Global Change Biology
• Main Authors: Jenouvrier, Stéphanie, Holland, Marika, Iles, David, Labrousse, Sara, Landrum, Laura, Garnier, Jimmy, Caswell, Hal, Weimerskirch, Henri, Larue, Michelle, Ji, Rubao, Barbraud, Christophe
• Other Authors: Woods Hole Oceanographic Institution (WHOI), Oceanography Section Boulder, National Center for Atmospheric Research Boulder (NCAR), Laboratoire de Mathématiques (LAMA), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Minnesota Twin Cities (UMN), University of Minnesota System (UMN)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: emission reduction pledges; seabirds; Antarctica; dispersion; climate change mitigation; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; Antarc*; Aptenodytes forsteri; Emperor penguins
• Online Access: https://hal.science/hal-02365591; https://hal.science/hal-02365591/document; https://hal.science/hal-02365591/file/Jenouvrier_et_al-2019-Global_Change_Biology%20%281%29.pdf; https://doi.org/10.1111/gcb.14864

International audience The Paris Agreement is a multinational initiative to combat climate change by keeping a global temperature increase in this century to 2°C above preindustrial levels while pursuing efforts to limit the increase to 1.5°C. Until recently, ensembles of coupled climate simulations producing temporal dynamics of climate en route to stable global mean temperature at 1.5 and 2°C above preindustrial levels were not available. Hence, the few studies that have assessed the ecological impact of the Paris Agreement used ad-hoc approaches. The development of new specific mitigation climate simulations now provides an unprecedented opportunity to inform ecological impact assessments. Here we project the dynamics of all known emperor penguin (Aptenodytes forsteri) colonies under new climate change scenarios meeting the Paris Agreement objectives using a climate-dependent-metapopulation model. Our model includes various dispersal behaviors so that penguins could modulate climate effects through movement and habitat selection. Under business-as-usual greenhouse gas emissions, we show that 80% of the colonies are projected to be quasiextinct by 2100, thus the total abundance of emperor penguins is projected to decline by at least 81% relative to its initial size, regardless of dispersal abilities. In contrast, if the Paris Agreement objectives are met, viable emperor penguin refuges will exist in Antarctica, and only 19% and 31% colonies are projected to be quasiextinct by 2100 under the Paris 1.5 and 2 climate scenarios respectively. As a result, the global population is projected to decline by at least by 31% under Paris 1.5 and 44% under Paris 2. However, population growth rates stabilize in 2060 such that the global population will be only declining at 0.07% under Paris 1.5 and 0.34% under Paris 2, thereby halting the global population decline. Hence, global climate policy has a larger capacity to safeguard the future of emperor penguins than their intrinsic dispersal abilities.