TY - JOUR
T1 - Extreme sea level implications of 1.5 °c, 2.0 °c, and 2.5 °c temperature stabilization targets in the 21st and 22nd centuries
AU - Rasmussen, D. J.
AU - Bittermann, Klaus
AU - Buchanan, Maya K.
AU - Kulp, Scott
AU - Strauss, Benjamin H.
AU - Kopp, Robert E.
AU - Oppenheimer, Michael
N1 - Funding Information:
We are grateful for comments from two anonymous reviewers and Carl-Friedrich Schleussner and colleagues at Climate Analytics. DJR and MKB were supported by the Science, Technology, and Environmental Policy (STEP) Program at Princeton. MO was supported in part by NSF EAR-1520683. REK was supported in part by a grant from Rhodium Group (for whom he has previously worked as a consultant), as part of the Climate Impact Lab consortium, and in part by NSF grant ICER-1663807 and by NASA grant 80NSSC17K0698. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modeling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model output (listed in SI table S-2). For CMIP, the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. Code for generating sea-level projections is available in the ProjectSL (https://github.com/bobkopp/ProjectSL), LocalizeSL (https://github.com/bobkopp/LocalizeSL), and SESL (https://github.com/bobkopp/SESL) repositories on Github. Code for generating extreme sea level projections is available in the hawaiiSL_process (https://github.com/dmr2/hawaiiSL_process), GPDfit (https://github.com/dmr2/GPDfit), return_curves (https://github.com/dmr2/return_curves), and amplification (https://github.com/dmr2/amplification) repositories on Github. The statements, findings, conclusions, and recommendations are those of the authors and do not necessarily reflect the views of the funding agencies.
Publisher Copyright:
© 2018 The Author(s). Published by IOP Publishing Ltd.
PY - 2018/3
Y1 - 2018/3
N2 - Sea-level rise (SLR) is magnifying the frequency and severity of extreme sea levels (ESLs) that can cause coastal flooding. The rate and amount of global mean sea-level (GMSL) rise is a function of the trajectory of global mean surface temperature (GMST). Therefore, temperature stabilization targets (e.g. 1.5 °C and 2.0 °C of warming above pre-industrial levels, as from the Paris Agreement) have important implications for coastal flood risk. Here, we assess, in a global network of tide gauges, the differences in the expected frequencies of ESLs between scenarios that stabilize GMST warming at 1.5 °C, 2.0 °C, and 2.5 °C above pre-industrial levels. We employ probabilistic, localized SLR projections and long-term hourly tide gauge records to estimate the expected frequencies of historical and future ESLs for the 21st and 22nd centuries. By 2100, under 1.5 °C, 2.0 °C, and 2.5 °C GMST stabilization, the median GMSL is projected to rise 48 cm (90% probability of 28-82 cm), 56 cm (28-96 cm), and 58 cm (37-93 cm), respectively. As an independent comparison, a semi-empirical sea level model calibrated to temperature and GMSL over the past two millennia estimates median GMSL rise within 7-8 cm of these projections. By 2150, relative to the 2.0 °C scenario and based on median sea level projections, GMST stabilization of 1.5 °C spares the inundation of lands currently home to about 5 million people, including 60 000 individuals currently residing in Small Island Developing States. We quantify projected changes to the expected frequency of historical 10-, 100-, and 500-year ESL events using frequency amplification factors that incorporate uncertainty in both local SLR and historical return periods of ESLs. By 2150, relative to a 2.0 °C scenario, the reduction in the frequency amplification of the historical 100 year ESL event arising from a 1.5 °C GMST stabilization is greatest in the eastern United States, with ESL event frequency amplification being reduced by about half at most tide gauges. In general, smaller reductions are projected for Small Island Developing States.
AB - Sea-level rise (SLR) is magnifying the frequency and severity of extreme sea levels (ESLs) that can cause coastal flooding. The rate and amount of global mean sea-level (GMSL) rise is a function of the trajectory of global mean surface temperature (GMST). Therefore, temperature stabilization targets (e.g. 1.5 °C and 2.0 °C of warming above pre-industrial levels, as from the Paris Agreement) have important implications for coastal flood risk. Here, we assess, in a global network of tide gauges, the differences in the expected frequencies of ESLs between scenarios that stabilize GMST warming at 1.5 °C, 2.0 °C, and 2.5 °C above pre-industrial levels. We employ probabilistic, localized SLR projections and long-term hourly tide gauge records to estimate the expected frequencies of historical and future ESLs for the 21st and 22nd centuries. By 2100, under 1.5 °C, 2.0 °C, and 2.5 °C GMST stabilization, the median GMSL is projected to rise 48 cm (90% probability of 28-82 cm), 56 cm (28-96 cm), and 58 cm (37-93 cm), respectively. As an independent comparison, a semi-empirical sea level model calibrated to temperature and GMSL over the past two millennia estimates median GMSL rise within 7-8 cm of these projections. By 2150, relative to the 2.0 °C scenario and based on median sea level projections, GMST stabilization of 1.5 °C spares the inundation of lands currently home to about 5 million people, including 60 000 individuals currently residing in Small Island Developing States. We quantify projected changes to the expected frequency of historical 10-, 100-, and 500-year ESL events using frequency amplification factors that incorporate uncertainty in both local SLR and historical return periods of ESLs. By 2150, relative to a 2.0 °C scenario, the reduction in the frequency amplification of the historical 100 year ESL event arising from a 1.5 °C GMST stabilization is greatest in the eastern United States, with ESL event frequency amplification being reduced by about half at most tide gauges. In general, smaller reductions are projected for Small Island Developing States.
KW - IPCC
KW - climate change impacts
KW - coastal flooding
KW - extreme sea levels
KW - paris agreement
KW - sea level rise
UR - http://www.scopus.com/inward/record.url?scp=85048251249&partnerID=8YFLogxK
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U2 - 10.1088/1748-9326/aaac87
DO - 10.1088/1748-9326/aaac87
M3 - Article
AN - SCOPUS:85048251249
SN - 1748-9326
VL - 13
JO - Environmental Research Letters
JF - Environmental Research Letters
IS - 3
M1 - 034040
ER -