Saline water intrusion in southern Vietnam

A recent study in a scientific journal said rising sea levels driven by global warming are on track to dramatically boost the frequency of coastal flooding worldwide by mid-century, especially in tropical regions. Scientists found that large cities along the North American seaboard like Vancouver, Seattle, San Francisco, and Los Angeles and along Europe’s Atlantic coast, will be highly exposed.

People living in the densely populated river deltas of Asia and Africa will be threatened by twice as many occurrences of serious flooding. Even at the low end of this sea rise spectrum, Mumbai, Kochi, Abidjan and many other cities would be significantly affected.

Lead author of the study Sean Vitousek, a climate scientist at the University of Illinois in Chicago, said an increase in flooding frequency with climate change will challenge the very existence and sustainability of coastal communities and cities around the globe. Coastal flooding is caused by severe storms, and is made worse when large waves, storm surge, and high tides converge.

Hurricane Sandy in the United States in 2012, which caused tens of billions of dollars in damage, and Typhoon Haiyan in the Philippines in 2013, which left more than 7,000 dead or missing, both involved devastating flooding.

If oceans rise just 25 centimeters by midcentury, floods will be a major challenge to tropical countries.The US National Oceanic and Atmospheric Administration predicts sea levels will rise globally as much as 2.5 meters by 2100.Global average temperatures have increased 1 degree Celsius since the mid-19th century, with most of that increase coming in the last 70 years.