Seattle considering a ban on use of natural gas on buildings built after July 2020, at least.
I think, probably a bad idea. The main alternative, used in buildings, is electricity. Guess what. A lot of our electricity comes from - natural gas. It doesn't really stop the use of natural gas; a fossil fuel.
Here in the Pacific Northwest, most of our electricity does come from hydro electric dams, but natural gas is another big source of our power. We have more hydro power than most places, but as our population and prosperity grows, there aren't enough rivers to keep up with demand. If there isn't enough hydro power, much of our electricity comes from natural gas; such as the Encogen power plant on Bellingham's waterfront.
Wind and solar generates power also, but not that big a percentage; yet. We need to use the wind and solar more.
Some people might say that electricity is best as it's the most adaptable. One can generate electricity from many sources, including solar, nuclear, coal and so forth. If we convert to "all electric," it might force us faster into adopting solar, but in the meantime most of our Northwest power is hydro. Hydro has it's problems too. Think dams on the salmon streams. There's even a proposal to dismantle some of the dams on the Columbia and Snake Rivers to help the salmon and the whales. Several native American tribes are pushing this idea.
The biggest problem is our transportation. Still way to dependent on fossil fuel powered cars and trucks. That's the true elephant in the room.