Factor Four and Factor Ten

Factor Four and Factor 10 are two examples of targets proposed for concomitant increases in ecoefficiency and reductions in material usage. Factor Four sets forth a target of doubling welfare while resource consumption simultaneously halves. Factor 10 proposes that material flows should be reduced by 90 percent over a period of 30–50 years.

Both Factor Four and Factor 10 were first proposed in 1994. Factor Four was set forth by Ernst von Weizsäcker and Amory Lovins, while Factor 10 was introduced in the Carnoules Declaration published by the International Factor 10 Club. Each proposal rose from the concern that worldwide stores of natural resources were being drawn down at unsustainable rates and the conviction that changes in production methods coupled with technological advances could be instituted ...