Sea level has been steadily rising over the past century, predominantly due to anthropogenic climate change. The rate of sea level rise will keep increasing with continued global warming, and, even if temperatures are stabilized through the phasing out of greenhouse gas emissions, sea level is still expected to rise for centuries. This will affect coastal areas worldwide, and robust projections are needed to assess mitigation options and guide adaptation measures. Here we combine the equilibrium response of the main sea level rise contributions with their last century's observed contribution to constrain projections of future sea level rise. Our model is calibrated to a set of observations for each contribution, and the observational and climate uncertainties are combined to produce uncertainty ranges for 21st century sea level rise. We project anthropogenic sea level rise of 28-56 cm, 37-77 cm, and 57-131 cm in 2100 for the greenhouse gas concentration scenarios RCP26, RCP45, and RCP85, respectively. Our uncertainty ranges for total sea level rise overlap with the process-based estimates of the Intergovernmental Panel on Climate Change. The "constrained extrapolation" approach generalizes earlier global semiempirical models and may therefore lead to a better understanding of the discrepancies with processbased projections.
Mengel, M., Potsdam Institute for Climate Impact Research, Potsdam, 14473, Germany, Physics Institute, Potsdam University, Potsdam, 14476, Germany; Levermann, A., Potsdam Institute for Climate Impact Research, Potsdam, 14473, Germany, Physics Institute, Potsdam University, Potsdam, 14476, Germany, Lamont Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States; Frieler, K., Potsdam Institute for Climate Impact Research, Potsdam, 14473, Germany; Robinson, A., Potsdam Institute for Climate Impact Research, Potsdam, 14473, Germany, Universidad Complutense de Madrid, Madrid, 28040, Spain, Instituto de Geociencias (IGEO), Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, Madrid, 28040, Spain; Marzeion, B., Institute of Geography, University of Bremen, Bremen, 28359, Germany; Winkelmann, R., Potsdam Institute for Climate Impact Research, Potsdam, 14473, Germany, Physics Institute, Potsdam University, Potsdam, 14476, Germany
Recommended Citation:
Mengel M.,Levermann A.,Frieler K.,et al. Future sea level rise constrained by observations and long-term commitment[J]. Proceedings of the National Academy of Sciences of the United States of America,2016-01-01,113(10)