Move to renewable energy. We have the necessary capacity, just keep installing renewable sources and phasing out the rest. Keep nuclear plants operational as long as they're safe, too, but don't waste too much resources building new ones.

Keep on moving electric storage from lithium ion to pumped hydro/sodium ion/other technologies depending on scale. Leave lithium ion for portable electronics and specialized cases only.

Develop better public transit networks, ideally make it free like in some cities. Also, make bicycle lanes mandatory for new neighborhoods, and convert old roads to have bicycle lanes whenever possible. With that, you won't need to ban cars as they'll grow less relevant (although you can increase tax on car sales to raise money and further disincentivise car ownership).

Also, develop high-speed rail whenever it makes sense, as an organic and much more ecological replacement for planes. Make sure they are modular enough to scale for demand, to avoid dragging extra.

Plant more trees and algae to help scrub the extra CO2. Intensify marine plastic collection efforts to assist the natural growth of marine ecosystems.

Ban petroleum-based plastics whenever possible. For most applications, there are more friendly biologically produced options; they are fairly cheap, too, it's just that regular plastic is even cheaper.

Extend reduce-reuse-recycle. Make more places serve into your own tare, make use (on a personal level) of what you normally throw away, and for what you do throw away, make sure it gets into recycling. Get creative! For example, did you know some used plastic bottles can be turned into a 3D printer filament? You can go wherever from there!

Reduce beef production/import and consumption. For what you do consume, make sure it comes from milk breeds, because otherwise you don't share the ecological footprint with the dairy, which skyrockets the footprint of a steak. In any case, beef is the single most terrible food source in terms of ecological footprint, being several times worse than pork, poultry and dozens to hundreds times worse than plant foods.

Oh, and the AI centers currently in construction by tech giants are becoming one extra major point of concern. We should review which of these are actually necessary, because this thing doesn't seem to stop scaling up, with some planned centers consuming as much energy as a major city.