title: Future sea level rise constrained by observations and long-term commitment.
abstract: 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 process-based projections.
authors.affiliation: Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany; Physics Institute, Potsdam University, 14476 Potsdam, Germany;
authors.forename: Matthias
authors.initials: M
authors.lastname: Mengel
authors.affiliation: Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany; Physics Institute, Potsdam University, 14476 Potsdam, Germany; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964; levermann@pik-potsdam.de.
authors.forename: Anders
authors.initials: A
authors.lastname: Levermann
authors.affiliation: Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany;
authors.forename: Katja
authors.initials: K
authors.lastname: Frieler
authors.affiliation: Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany; Universidad Complutense de Madrid, 28040 Madrid, Spain; Instituto de Geociencias (IGEO), Consejo Superior de Investigaciones Científicas - Universidad Complutense de Madrid, 28040 Madrid, Spain;
authors.forename: Alexander
authors.initials: A
authors.lastname: Robinson
authors.affiliation: Institute of Geography, University of Bremen, 28359 Bremen, Germany.
authors.forename: Ben
authors.initials: B
authors.lastname: Marzeion
authors.affiliation: Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany; Physics Institute, Potsdam University, 14476 Potsdam, Germany;
authors.forename: Ricarda
authors.initials: R
authors.lastname: Winkelmann
keywords: climate change; climate impacts; sea level rise