Thursday, July 05, 2018

Rising Sea Levels Could Cost the World $14 Trillion a Year by 2100

Large rises in sea level will threaten low-lying island nations like the Maldives (Credit: ioppublishing.org)  Click to Enlarge.
Failure to meet the United Nations' 2ºC warming limits will lead to sea level rise and dire global economic consequences, new research has warned.

Published Wednesday in Environmental Research Letters, a study led by the UK National Oceanographic Centre (NOC) found flooding from rising sea levels could cost $14 trillion worldwide annually by 2100, if the target of holding global temperatures below 2ºC above pre-industrial levels is missed.

The researchers also found that upper-middle income countries such as China would see the largest increase in flood costs, whereas the highest income countries would suffer the least, thanks to existing high levels of protection infrastructure.

Dr Svetlana Jevrejeva, from the NOC, is the study's lead author.  She said:  "More than 600 million people live in low-elevation coastal areas, less than 10 meters above sea level.  In a warming climate, global sea level will rise due to melting of land-based glaciers and ice sheets, and from the thermal expansion of ocean waters.  So, sea level rise is one of the most damaging aspects of our warming climate."

Sea level projections exist for emissions scenarios and socio-economic scenarios.  However, there are no scenarios covering limiting warming below the 2°C and 1.5°C targets during the entire 21st century and beyond.

The study team explored the pace and consequences of global and regional sea level rise with restricted warming of 1.5 ºC and 2 ºC, and compared them to sea level projections with unmitigated warming following emissions scenario Representative Concentration Pathway (RCP) 8.5.

Using World Bank income groups (high, upper middle, lower middle and low income countries), they then assessed the impact of sea level rise in coastal areas from a global perspective, and for some individual countries using the Dynamic Interactive Vulnerability Assessment modelling framework.

Dr Jevrejeva said:  "We found that with a temperature rise trajectory of 1.5°C, by 2100 the median sea level will have risen by 0.52m (1.7ft).  But, if the 2°C target is missed, we will see a median sea level rise of 0.86m (2.8ft), and a worst-case rise of 1.8m (5.9ft).

Read more at Rising Sea Levels Could Cost the World $14 Trillion a Year by 2100

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