Climate Science for 2050

Guy Pierre Brasseur^1*Detlef Stammer²Pierre Friedlingstein³Gabriele Hegerl⁴T Shaw⁵Kevin Edward Trenberth⁶Carolina Vera⁷A Berger⁸H Cleugh⁹S Easterbrook¹⁰P Edwards¹¹M E Mann¹²Valerie Masson-Delmotte¹³Jadwiga Richter⁶Gavin A Schmidt¹⁴Mary Cathrine Scholes¹⁵T F Stocker¹⁶Martin Visbeck¹⁷Guoxiong Wu¹⁸

• ¹Max Planck Institute for Meteorology, Max Planck Society, Hamburg, Germany
• ²University of Hamburg, Hamburg, Hamburg, Germany
• ³University of Exeter, Exeter, England, United Kingdom
• ⁴University of Edinburgh, Edinburgh, Scotland, United Kingdom
• ⁵The College, The University of Chicago, Chicago, Illinois, United States
• ⁶National Center for Atmospheric Research (UCAR), Boulder, Colorado, United States
• ⁷University of Buenos Aires, Buenos Aires, Buenos Aires, Argentina
• ⁸Université Catholique de Louvain, Louvain-la-Neuve, Walloon Brabant, Belgium
• ⁹Australian National University, Canberra, Australian Capital Territory, Australia
• ¹⁰University of Toronto, Toronto, Ontario, Canada
• ¹¹Stanford University, Stanford, California, United States
• ¹²University of Pennsylvania, Philadelphia, Pennsylvania, United States
• ¹³Université Paris-Saclay, Saint Aubin, France
• ¹⁴Goddard Institute for Space Studies (NASA), New York, New York, United States
• ¹⁵University of the Witwatersrand, Johannesburg, South Africa
• ¹⁶University of Bern, Bern, Bern, Switzerland
• ¹⁷GEOMAR Helmholtz Center for Ocean Research Kiel, Helmholtz Association of German Research Centres (HZ), Kiel, Schleswig-Holstein, Germany
• ¹⁸Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS), Beijing, Beijing Municipality, China

Knowledge of the functioning of the climate system, including the physical, dynamical and biogeochemical feedback processes expected to occur in response to anthropogenic climate forcing, has increased substantially over recent decades. Today, climate science is at a crossroads, with new and urgent demands arising from the needs of society to deal with future climate change. The climate science community needs to refine its strategic goals to meet these demands rapidly. All possible worlds in 2050, with a larger global population, unprecedented climate conditions with higher temperatures, more frequent extreme weather events, sea level rise, disrupted ecosystems, changes in habitability and increased climate-induced displacement and migration, and the emergence of new geopolitical tensions, will require limiting society's vulnerability. The development of a skillful climate information system is required to inform decision-makers and the public around the world about the local and remote impacts of climate change, and guide them in optimizing their adaptation and mitigation agendas. This information will help manage renewable resources in a warmer world and strengthen resilience to the expected interconnected impacts of climate change. In this paper, we summarize the major advances needed to understand the dynamics of the Earth system. We highlight the need to develop an integrated information system accessible to decision-makers and citizens, and present some of the key scientific questions that need to be addressed. Finally, we speculate about the values and ethics of climate science and the nature of climate research in a world that will be increasingly affected by global warming.