Stopping the digging up and burning of carbon fuels is a start.

It took the planet literal hundreds of thousands of years to get the carbon level of the atmosphere down to preindustrial levels, and we’ve undone that in the past near 200

It’ll take a lot, but it’s not impossible to increase carbon capture, use ground based solar to give shade and re-green some desert areas (proven to work) we can easily provide the entire earth’s power requirements while also increasing the carbon sequestration.