If you believe in Capitalism:

Step 1: Assign a cost for CO2 emissions.

Step 2: Let the market deal with the costs.

Step 3: Asses if the cost was at the right amount. Adjust if necessary and repeat.

If you don't believe in Capitalism:

Step 1: Change the governmental system to a system of your liking.

Step 2: Find a way in this new system to control what companies do. e.g. state planned economics, regulations, etc.