What Biden has done is to cut the issuance of drilling leases to the minimum required by law, pass the Inflation Reduction Act, enact a regulation to force vehicle electrification, and similarly force fossil fuels out of most power plants.
What Biden has not done: stop issuing drilling permits or impose export restrictions on fossil fuels. The former has some serious limits because of how the courts treat the right to drill as a property right once you hold a drilling lease, and the latter is simply untested.
There is no undoing what we’ve done. The icecaps will soon be gone and once they are gone they are gone for good
The icecaps didn’t always exist, and they can reform. It will take a long time mind you.
Putting up a solar shade would artificially cool the Earth enough for the ice caps to refreeze.
We really ought to collect all of that meltwater and distribute it to drought-stricken regions anyway.