> Changing the amount of CO2 in the atmosphere is not the only way to change the climate, and is unlikely to be the cheapest way to change the climate. We are

> Changing the amount of CO2 in the atmosphere is not the only way to change the climate, and is unlikely to be the cheapest way to change the climate. We are changing the amount of CO2 in the atmosphere and it is the main driver for the climate change. You probably wanted to say, that not changing the amount of CO2 is unlikely to be the cheapest way to keep the climate as it is, didn't you?