A study suggests that sea levels could rise an average of 0.9 meters if climate change causes a temperature rise of 5 °C by 2100. Researchers consider a 2 °C rise above preindustrial temperatures an appropriate threshold beyond which climate change repercussions become high. According to the climate change scenarios known as Representative Concentration Pathway (RCP) 4.5 and RCP 8.5, a 2 °C-increase in temperature could occur between 2040 and 2050. To study the effect of rising temperatures on global coastlines, Svetlana Jevrejeva and colleagues generated probabilistic sea level rise projections with global warming at and above 2 °C, including projections for 136 coastal cities. If midcentury temperature rise reaches 2 °C, global sea level could rise by approximately 0.2 meters, but, due to ocean dynamics, 90% of coastal areas could experience higher sea level rise. For example, the authors predict up to a 0.4-meter rise along the Atlantic coasts of North America and Norway. If temperatures rise by 5 °C by 2100, as predicted by RCP 8.5, coastal sea level could rise an average of 0.9 meters. Furthermore, projected sea level rise could exceed 1.8 meters by 2100 at most of the coastal cities included in the study. According to the authors, coastal communities associated with rapidly growing cities and vulnerable tropical coastal ecosystems might have little time after midcentury to adapt to sea level rise. - Read at PNAS.org
Article #16-05312: “Coastal sea level rise with warming above 2 °C,” by Svetlana Jevrejeva, Luke Jackson, Riccardo Riva, Aslak Grinsted, and John Moore.