Achieving the Paris Agreement objectives will likely halt future declines of emperor penguins

The total population size of emperor penguins projected using climate model simulations from CESM with different emissions scenarios
Figure: The total population size of emperor penguins projected using climate model simulations from CESM with different emissions scenarios. Included are the results using simulations from the CESM Large Ensemble, with an unmitigated RCP8.5 scenario (red line), CESM simulations which meet the Paris Agreement target of 2oC global warming (blue line), and CESM simulations which meet the Paris Agreement target of 1.5oC global warming (green line).

Many species are threatened by extinction due to future climate change. While the Paris Agreement seeks to limit global warming to under 2°C, its ability to prevent species extinction is unknown. Here, we use simulations of CESM to explore how environmental changes under different emissions targets will affect the population size of emperor penguins. We forecast the dynamics of all known emperor penguin colonies using model simulations that are fully consistent with meeting the Paris Agreement objectives, and we compare these to a baseline scenario of unmitigated emissions. Global declines of emperor penguins are predicted under the environmental changes predicted using the CESM1 Large Ensemble, which uses the RCP8.5 unmitigated emission scenario. In contrast, if the Paris Agreement objectives are met, viable emperor penguin refuges will exist in Antarctica, dramatically improving their global population viability. This shows that near-term unified action on climate change has the ability to radically alter the future of earth’s biota.

Reference

  • Jenouvrier, S., M. Holland, D. Iles, S. Labrousse, L. Landrum, J. Garnier, H. Caswell, H. Weimerskirch, M. LaRue, J. Rubao, and C. Barbraud, The Paris Agreement objectives will likely halt future declines of emperor penguins, Global Change Biology, 2019, accepted.