The Naked and the Dead

It’s hard to escape observation by satellites, and tough to argue with the data they present, some of which would be nearly impossible to gather accurately from here on the ground. Using NASA satellite imagery, scientists at the University of Maryland have been tracking the total amount of vegetation—or lack of it—worldwide. As this article from the NASA Earth Observatory notes, they’ve seen 94,000 square kilometers, an area greater than Lake Superior, lose vegetation since 2000. China has lost the most—35%—mainly because of its expanding cities, suburbs, and roads. Much of the newly denuded ground is in coastal areas.

After China, the US has lost the most vegetation—17%—but for somewhat different reasons. Growing cities and suburbs are part of the equation, but mining and energy production—that is, areas where oil and natural gas are extracted—also contributed, particularly in southeastern Texas.

Interestingly, population growth and loss of vegetation don’t necessarily go hand in hand. Parts of Africa, the researchers say, have gained in population but have not lost significant amounts of vegetation.

Note that “vegetation” in this context doesn’t necessarily equal tree canopy. As I mentioned here a year ago, the organization Global Forest Watch estimates the Earth has lost about 6% of its tree cover since 2000. That’s not a uniform number, either, and some places are losing far more than that to logging (Indonesia, for example), agriculture (the Philippines and elsewhere), and fires, often deliberately set to clear land and fertilize the soil for crops (Angola). The Global Forest Watch has an interactive map that lets users take a closer look at specific areas.

You can see a few of the University of Maryland scientists’ bare ground maps here.