FAA REGULATORS are streamlining flight routes around Atlanta and Charlotte, North Carolina, as part of an effort to save fuel and reduce delays at major airports across the country. Reading the article, it strikes me that the cost-to-benefit ratio is very high, but here is the nut graf:

The FAA didn’t address how it expects to deal with potential environmental challenges to the new routes.

There are only two realistic ways to deal with 'environmental challenges' -- ignore them or quit flying.