It's also an effective educational resource. The U.S. Environmental Protection Agency regulates sulfur dioxide emissions of 800 companies. Based on previous emissions, the companies receive an annual allotment of allowances. Each allowance equals one ton of pollution. The total number of allowances is reduced each year to reduce pollution in the atmosphere.
Companies usually gain credits when they voluntarily reduce emissions below required levels.
These allowances can be bought and sold. The conservancy buys the credits on the open market or at the EPA's annual sulfur dioxide emission auction. In so doing, pollutants that might end up in the atmosphere are put out of commission. So far, the conservancy has bought and retired 1,350 sulfur dioxide credits, reducing the amount of pollution by 1,350 tons. Reducing energy consumption is as simple as rethinking old habits.