all of which use fassel fuel.tomobiles, kira, are by far the largest contributors. >> so what has the federal government been doing to solve the greenhouse gas pollution problem or emission problem? >> it's an old problem, we know that. periodically the environmental protection agency announces new gas mileage rules for cars and trucks in the coming years. now the better the gas mileage, well, the fewer the greenhouse gas emissions. in 2011 during the obama administration the epa established a 54.5 miles per gallon requirement by 2025. that's a regulation that was and continues to be contested by the automobile industry. still, regulations have brought success. according to the epa as of 2015 greenhouse gas emissions were reduced to 1995 levels this despite more cars, trucks, planes and ships this in use. >> wow. >> nevertheless the automobile industry, as we expect, is requesting an adjustment to that requirement which may well be gra granted by the trump administration as part of its effort to ease emissions reg