According to the American Iron and Steel Institute (AISI), the U.S. steel industry reduced its energy intensity per ton of steel shipped by approximately 31% from 1990 to 2008. This figure is down slightly from 33% in 2007 due to a large drop-off in production starting in the fourth quarter of 2008. On average, 1.19 tons of CO2 was emitted in 2008 for every ton of steel produced in the U.S. AISI notes that the low CO2 intensity of American-manufactured steel, as well as its infinite recyclability, is why steel products have such low environmental impacts during their life cycle.