Mangroves as Protection from Storm Surges in a Changing Climate

Adaptation to climate change includes
addressing sea level rise and increased storm surges in many
coastal areas. Mangroves can substantially reduce the
vulnerability of the adjacent coastal land from inundation
and erosion. However, climate change poses a large threat to
mangroves. This paper quantifies the coastal protection
provided by mangroves for 42 developing countries in the
current climate, and a future climate change scenario with a
one-meter sea level rise and 10 percent intensification of
storms. The benefits of the coastal protection provided by
mangroves are measured in terms of population and gross
domestic product at a reduced risk from inundation; the loss
of benefits under climate change is measured as the
increased population and gross domestic product at risk. The
findings demonstrate that although sea level rise and
increased storm intensity would increase storm surge areas
and the amounts of built resources at risk, the greatest
impact is the expected loss of mangroves. Under current
climate and mangrove coverage, 3.5 million people and
roughly $400 million in gross domestic product of are at
risk. In the future climate change scenario, the vulnerable
population and gross domestic product at risk would increase
by 103 and 233 percent, respectively. The greatest risk is
in East Asia, especially in Indonesia, the Philippines, and Myanmar.