The FAA the other day released a request for alternate fuels to test in what it hopes will be an accelerated adoption of an unleaded avgas into the GA fleet. It's aiming for five years. I'll bet my house that won't happen.
In any case, upon the announcement, alphabet groups rose as if as one to applaud the move by the FAA to take the initiative to do something about the 100LL problem.
It is a problem, though it is by nature far more of a political problem than an environmental one.