"The federal government announced the first national emissions and fuel economy standards for heavy vehicles on Monday, one of a series of regulatory steps that the Obama administration is taking to increase energy efficiency and reduce atmospheric pollution in the absence of Congressional action on climate change.
The administration also announced approval of a major solar power installation on public land in the California desert, a step toward weaning the nation from dependence on fossil fuels. Together they represent what President Obama has called a more “bite-size” approach to global warming that he intends to pursue while efforts to pass comprehensive legislation are stalled.
The mileage proposal, which is scheduled to become final next year after a period of public comment, will apply to tractor-trailers, buses, delivery vans, heavy pickup trucks, cement mixers and many other classes of vehicles. It will cover new vehicles manufactured between 2014 and 2018."