Up A River?

The world’s deltas are becoming increasingly vulnerable to climate change.

August 10, 2015

This image shows four decades of coastal land and wetland loss in the Mississippi River Delta, as observed by Landsat. Credit: Zachary Tessler (Data: USGS/NASA Landsat Program).

Hundreds of millions of people around the world live and work on deltas, but as climate change raises sea levels, that’s becoming risky real estate. A new study published in Science analyzed 48 major river deltas to see how vulnerable they are to storms and floods, and found that in many places—South Asia's Ganges-Brahmaputra Delta for one—humans are heightening their chances for disaster by overpopulating, extracting oil and gas from the land (causing it to sink, the Washington Post describes), and developing the rivers’ banks.

Even in wealthy countries that can afford to build protective infrastructure—take the heavily bolstered Mississippi and Rhine rivers, for example—those protections aren’t sustainable in the long run. The researchers found that as the costs of maintaining coastal-defense systems increases over time, the relative risk that communities face will also rise—in the case of the Mississippi and Rhine, four to eight times. 

A false-color composite image of the Mississippi River taken in 2001, provided by the USGS EROS Data Center Satellite Systems Branch

A false-color composite image of the Ganges Delta taken in 2000, provided by the USGS EROS Data Center Satellite Systems Branch


onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.

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