6 . Conservationists go to war over whether humans are the measure of nature’s value. New Conservationists argue such trade-offs are necessary in this human dominated epoch. And they support “re-wilding”, a concept originally proposed by Soule where people curtail economic growth and withdraw from landscapes, which then return to nature.

New Conservationists believe the withdrawal could happen together with economic growth. The California-based Breakthrough Institute believes in a future where most people live in cities and rely less on natural resources for economic growth.

They would get food from industrial agriculture, including genetically modified foods, desalination intensified meat production and aquaculture, all of which have a smaller land footprint. And they would get their energy from renewables and natural gas.

Driving these profound shifts would be greater efficiency of production, where more products could be manufactured from fewer inputs. And some unsustainable commodities would be replaced in the market by other, greener ones — natural gas for coal, for instance, explained Michael Heisenberg, president of the Breakthrough Institute. Nature would, in essence, be decoupled from the economy.

And then he added a caveat: We are not suggesting decoupling as the paradigm to save the world, or that it solves all the problems or eliminates all the trade-offs.

Cynics (悲观者) may say all this sounds too utopian, but Breakthrough maintains the world is already on this path toward decoupling. Nowhere is this more evident than in the United Sates, according to Iddo Wernick, a research scholar at the Rockefeller University, who has examined the nation’s use of 100 main commodities.

Wenick and his colleagues looked at data carefully from the U.S. Geological Survey National Minerals Information Center, which keeps a record of commodities used from 1900 through the present day. They found that the use of 36 commodities (sand, iron ore, cotton etc.) in the U. S. Economy had peaked.

Another 53 commodities (nitrogen, timber, beef, etc.) are being used more efficiently per dollar value of gross domestic product than in the pre-1970s era. Their use would peak soon, Wernick said.

Only 11 commodities (industrial diamond, indium, chicken, etc.) are increasing in use (Greenwire, Nov.6), and most of these are employed by industries in small quantities to improve systems processes. Chicken use is rising because people are eating less beef, a desirable development since poultry cultivation has a smaller environmental footprint.

The numbers show the United States has not intensified resource consumption since the 1970s even while increasing its GDP and population, said Jesse Ausubel of the Rockefeller University.

“It seems like the 20th-century expectation we had, we were always assuming the future entailed greater consumption of resources,” Ausubel said. “But what we are seeing in the developed countries is, of course, peaks.”