Vox: On Friday, the Environmental Protection Agency proposed sweeping new regulations to slash greenhouse-gas emissions from all new heavy trucks, buses, and vans. This is a major piece of President Obama's broader plan to tackle global warming.
The rationale sounds simple enough: Even though trucks make up just 5 percent of vehicles on the road, they account for 20 percent of greenhouse-gas emissions from transportation (since they're constantly in use). So... we should clean 'em up.
To that end,...