Quantifying Land and People Exposed to Sea‐Level Rise with No Mitigation and 1.5°C and 2.0°C Rise in Global Temperatures to Year 2300

Abstract

We use multiple synthetic mitigation sea‐level scenarios, together with a non‐mitigation sea‐level scenario from the Warming Acidification and Sea‐level Projector model. We find sea‐level rise (SLR) continues to accelerate post‐2100 for all but the most aggressive mitigation scenarios indicative of 1.5°C and 2.0°C. Using the Dynamic Interactive Vulnerability Assessment modeling framework, we project land and population exposed in the 1 in 100 year coastal flood plain under SLR and population change. In 2000, the flood plain is estimated at 540 × 103 km2. By 2100, under the mitigation scenarios, it ranges between 610 × 103 and 640 × 103 km2 (580 × 103 and 700 × 103 km2 for the 5th and 95th percentiles). Thus differences between the mitigation scenarios are small in 2100. However, in 2300, flood plains are projected to increase to between 700 × 103 and 960 × 103 km2 in 2300 (610 × 103 and 1290 × 103 km2) for the mitigation scenarios, but 1630 × 103 km2 (1190 × 103 and 2220 × 103 km2) for the non‐mitigation scenario. The proportion of global population exposed to SLR in 2300 is projected to be between 1.5% and 5.4% (1.2%–7.6%) (assuming no population growth after 2100) for the aggressive mitigation and the non‐mitigation scenario, respectively. Hence over centennial timescales there are significant benefits to climate change mitigation and temperature stabilization. However, sea‐levels will continue to rise albeit at lower rates. Thus potential impacts will keep increasing necessitating adaptation to existing coastal infrastructure and the careful planning of new coastal developments.

Evolution of 21st Century Sea Level Rise Projections

“…However, as the world moves closer to the year 2100, it is essential to understand SLR and the impacts of rising sea levels on longer time scales (Brown et al, 2018;P. However, as the world moves closer to the year 2100, it is essential to understand SLR and the impacts of rising sea levels on longer time scales (Brown et al, 2018;P.…”

“…However, as the world moves closer to the year 2100, it is essential to understand SLR and the impacts of rising sea levels on longer time scales (Brown et al, 2018;P. A few recent studies have sought to project SLR for 2300, with median estimates of global-mean SLR ranging from 1.00 m under RCP2.6 to 11.69 m under RCP8.5 (Brown et al, 2018;Kopp et al, 2014Kopp et al, , 2017Schaeffer et al, 2012), while studies looking at multimillennial sea level commitments have suggested over 20 m of future global-mean SLR for emission scenarios similar to RCP4.5 (P. U. A few recent studies have sought to project SLR for 2300, with median estimates of global-mean SLR ranging from 1.00 m under RCP2.6 to 11.69 m under RCP8.5 (Brown et al, 2018;Kopp et al, 2014Kopp et al, , 2017Schaeffer et al, 2012), while studies looking at multimillennial sea level commitments have suggested over 20 m of future global-mean SLR for emission scenarios similar to RCP4.5 (P. U.…”

“…The majority of studies seeking to project future SLR have focused on the year 2100. However, as the world moves closer to the year 2100, it is essential to understand SLR and the impacts of rising sea levels on longer time scales (Brown et al, 2018;P. U. Clark et al, 2016;Levermann et al, 2013).…”

“…U. Clark et al, 2016;Levermann et al, 2013). A few recent studies have sought to project SLR for 2300, with median estimates of global-mean SLR ranging from 1.00 m under RCP2.6 to 11.69 m under RCP8.5 (Brown et al, 2018;Kopp et al, 2014Kopp et al, , 2017Schaeffer et al, 2012), while studies looking at multimillennial sea level commitments have suggested over 20 m of future global-mean SLR for emission scenarios similar to RCP4.5 (P. U. Clark et al, 2016;Levermann et al, 2013).…”

Intersecting vulnerabilities: Climatic and demographic contributions to future population exposure to Aedes-borne viruses in the United States

“…This scenario framework is made up of climate scenarios -Representative Concentration Pathways, RCPs (van Vuuren et al, 2011) -and socioeconomic scenarios -Shared Socioeconomic Pathways, SSPs -combined together into a scenario matrix . This framework (hereafter referred as SSP*RCP framework) is being increasingly used in IAV studies to explore future population exposure -under socioeconomic and climatic uncertainty -to a wide range of climate-related risks such as extreme heat (e.g., Jones et al, 2018, Rohat et al, 2019, inland and coastal flooding (e.g., Alfieri et al, 2015, Brown et al, 2018, fire risk (Knorr et al, 2016), air pollution (Chowdhury et al, 2018), and food security (e.g., Hasegawa et al, 2014). The SSP*RCP framework has been applied to some VBD-related studies (e.g., Monaghan et al 2016.…”