Even assuming it is not already too late to significantly mitigate U.S. climate change factors (a big assumption, frankly), it's definitely out of reach in the current political structure. It doesn't matter what the Executive branch tries to do if both Congress and the Judiciary block it. Our system of checks and balances ensures a stalemate at best, and a rollback to even worse behavior seems entirely likely.
We lost this battle when Mitch McConnell stacked the Supreme Court. Dems always seem to show up at the fight with brass knuckles while the GOP is armed with Uzis.