Earth may be nearing an ecological tipping point that threatens biodiversity, food production and water supplies as humans consume resources at an unsustainable pace, according to an article to be published tomorrow in the journal Nature.
About 43 percent of the Earth’s surface has been built upon or is being used for agriculture to support the planet’s 7 billion inhabitants, according to Anthony Barnosky, a professor of integrated biology at the University of California, Berkeley. As that figure approaches 50 percent, there may be irreversible and significant environmental changes.
“Unless we take note of exactly how we’re changing the world and what that means in a biological sense, we can’t steer the ship,” Barnosky said in a phone interview yesterday. Without policy and behavioral changes, the planet’s environment will suffer. “When that happens you get a period of societal adjustment that usually includes economic problems, wars and famines.”
Humans consume 2.25 acres of resources per capita, and with the Earth’s population projected to reach 9 billion by 2045, half of all land may be in use by 2025, Barnosky said. That includes Antarctica, Greenland and other mostly uninhabitable regions.
Small-scale ecosystems have shown that once 50 percent of an area is altered, biodiversity is often lost and animal and plant species are at risk of extinction, he said.
There’s “an urgent need” to reduce population growth and per-capita resource use, grow more food on less land and replace fossil fuels with renewable-energy sources, according to the report. Barnosky, the study’s lead author, spent 18 months working with 21 scientists from the U.S., Canada, Chile, Finland and Spain researching and writing the article.
“It’s a global society, and these are global problems, and the only way we can solve them is through global cooperation,” Barnosky said. “The big winners in the world 50 years from now will be the nations that have developed new forms of energy. Those nations and entrepreneurs are going to come out ahead.”