Scientific American: More than 50,000 high-polluting diesel engines have been cleaned up or removed from U.S. roads in a federal program designed to reduce smog and greenhouse gases, according to a new Environmental Protection Agency report to Congress.
While industry and environmental officials call the program a success, it is now threatened with a 70 percent cut in funding under the Obama Administration's new budget.
School buses and long-haul trucks accounted for almost 40,000 of the approximately 52,000 engines...