How much of the Earth is Protected?

Scientists like biologist E.O. Wilson are calling for half of the Earth’s surface and seas to be set aside as protected landscape to preserve humanity. With this goal in mind, one might wonder exactly how much is already protected. 

To answer this, it’s important to know how much of the Earth has been touched by humans. 

A report by the Wildlife Conservation Society, released at the start of the new millennium, found that 83 percent of the total land surface and 98 percent of the areas where it is possible to grow the world's three main crops—rice, wheat and maize—has been touched by human activities. 

The authors of the study used four variables to measure human influence: population density, access from roads and waterways, electrical power infrastructure and land transformation. 

When human influence is considered in that way, it’s safe to say humans have a huge influence on the Earth’s ecosystems. 

Most people in the United States still think there are really big wild spaces out there; especially in the west. But this is just not true. In fact, the study found that only 20 percent of the land in the continental United States is within 500 meters of a paved road. That works out to about 5 1/2 football fields. And more of the nation is even closer to a paved road. That’s a lot of human influence. 

Now, getting back to the original question—how much of the Earth is already protected? The World Database on Protected Areas, which is a joint project of the United Nations Environment Program and the International Union for Conservation in Nature, found that about 15 percent of Earth’s land area and about three percent of the ocean area is protected. That was reported in 2015 and the trend for protecting land is growing. 

That protected area is found in roughly 161,000 reserves or parks on land and in about 6,500 ocean conservation areas. 

Not surprisingly, the Wildlife Conservation Society’s study found the places most heavily influenced by human activity are the world’s largest cities, such as New York. 

The least affected places are the most remote, such as the Arctic Tundra. 

About 60 percent of the world’s land surface is found on a continuum between those two extremes. Scientists say while it is important to preserve land areas near where people live, the greatest opportunity for conservation lies along that continuum. This is where scientists like Wilson might find hope in moving toward their conservation goal, and the preservation of humanity. 

—Frank Graff

Frank Graff is a producer/reporter with UNC-TV, focusing on North Carolina Science Now, a weekly science series that airs Wednesdays, beginning in August 2013, as part of North Carolina Now on UNC-TV. In addition to producing these special segments, Frank will provide additional information related to his stories through this North Carolina Science Now Reporter's Blog! 


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