. >>> clean air act imposing tougher eapplication standards but critics say they would come with a bigprice tag. john terret is in washington. john. >> yes, good evening to you john. the obama administration has done this so far to the auto makers, to truckers, even to power stations and now they're about to do it to the airline industry as well, telling them the pollution to their jet engines is a hazard to human health. once that announcement has come down we expenditure it next week you bet your bottom dlor dollar the regulations for greenhouse gases won't be far away. just across the river at the white house with where you get a bird's eye view of the planes, president obama is concerned about what's spewing from the jet engines the epa is expected to say those fumes will be endangering human health. the clean air act of 1970 requires the feds to regulate pollutants that endanger human health. they've done it with cars and trucks and power stations. now they're turning their attention to aircraft. it would lead to much tighter emissions regulations ahead. the aviation industry says

. >> what do those eapplications do to the chemicals of the chemistry of the water? >> basically the co2 becomes an acid this ought to be a very crucial problem especially in the early development of larvae. >> reporter: for juvenile oysters that can be lethal preventing them from forming shells. it is not just oysters that are at risk but lobsters crabs and clams. it projects by the year 2100, ocean acidity will increase by a factor of 75. in water that a-- much 75, in water that acidic, the shell dissolved in just 45 days. >> what others other species is it affecting? >> great great grandfather first harvested oysters have this he be beach in the 1990s. taylor shell fich is a classic business. she and her siblings are the fifth generation of taylors to work here. much like farmers planting a crop, the taylors use juvenile oysters to seed these vast tidal beaches. here they will grow into adults ready to harvest. according to the taylors ocean acidification has cost them dearly in lost production. >> what that meant was we didn't have any oysters to plant on the bea

it's a polluter, it welcomes the new rules and points out it's already doing quite a lot to kill eapplications. >> power plants are 50% automobiles are almost 25% of those, aircraft are 2%. we're not saying that's nothing but we're saying we're working on the issue and this is another arrow in the quiver to address that. >> reporter: in fact according to the epa american aircraft are responsible for about 11% of greenhouse gas emissions in the u.s. transportation sector. 3% of all american greenhouse gas emissions and about 29% of all aircraft greenhouse gas emissions worldwide. the industry accounts for about 5% of u.s. gdp or overall economic growth, nonetheless environmentalists say it's the only key industrial sector that goes unregulated when it comes to emissions. >> this is a totally unregulated industry and they are the largest remaining unregulated industry in the transportation sector. greenhouse gases are a threat oour planet and they should be reduced and epa is only announcing its intent to reduce emissions. they're not telling the industry yet what it has to do. >> reporter: so i