0

Putting a Price Tag on Nature’s Defenses

ecosrvcsCoral reefs have proved valuable to coastal regions by helping to blunt shore erosion from storm waves.

REUTERS

By CARL ZIMMER

June 5, 2014

After Hurricane Katrina devastated New Orleans, the United States Army Corps of Engineers got to work on a massive network of levees and flood walls to protect against future catastrophes. Finally completed in 2012, the project ended up costing $14.5 billion — and that figure didn’t include the upkeep these defenses will require in years to come, not to mention the cost of someday replacing them altogether.

But levees aren’t the only things that protect coasts from storm damage. Nature offers protection, too. Coastal marshes absorb the wind energy and waves of storms, weakening their impact farther inland. And while it’s expensive to maintain man-made defenses, wetlands rebuild themselves.

Protection from storms is just one of many services that ecosystems provide us — services that we’d otherwise have to pay for. In 1997, a team of scientists decided to estimate how much they are actually worth. Worldwide, they concluded, the price tag was $33 trillion — equivalent to $48.7 trillion in today’s dollars. Put another way, the services ecosystems provide us — whether shielding us from storms, preventing soil erosion or soaking up the greenhouse gases that lead to global warming — were twice as valuable as the gross national product of every country on Earth in 1997.

Dr. Costanza and his colleagues have now updated the 1997 estimate in a new study, published in the May issue of the journal Global Environmental Change, and concluded that the original estimate was far too low. The true value of the services of the world’s ecosystems is at least three times as high, they said.

Read the full article here.

 

Share

Leave a Reply




If you want a picture to show with your comment, go get a Gravatar.