The US government implemented no such thing.

It happened under Trump's tenure due to the economics of coal power and wind, despite his campaign promises to prop up coal and the phase out of wind power subsidies.

The reduction isn't even close to the scale of the cuts required to make meaningful progress on climate.

As someone earlier in the thread said, look how much progress has been made under a hostile policy regime. Imagine if there was actually a carbon tax and oil subsidies were transferred to clean tech.