U.S. EPA Administrator Christie Todd Whitman yesterday proposed replacing five of the government’s toughest air-pollution programs with a single approach favored by the electricity industry. Rules to limit mercury emissions, reduce emissions from Midwestern power plants, and restore visibility in national parks would be scrapped. As a replacement, Whitman sketched a plan to reduce nitrogen oxide, sulfur dioxide, and mercury emissions by expanding pollution-credit trading programs. Whitman also contradicted comments by U.S. Secretary of State Colin Powell last week and said the Bush administration would probably not have ready by this fall a substantive alternative to the Kyoto treaty on climate change. Sen. James Jeffords (I-Vt.), the chair of the Senate Environmental and Publics Works Committee, sparred with Whitman over the issue of climate change. He has introduced a bill requiring power plants to reduce their emissions of carbon dioxide, the main greenhouse gas.