But isn't this really a supply side problem? If we had cost competitive green sources of energy which are trending to be cheaper then carbon emitting ones - how

But isn't this really a supply side problem? If we had cost competitive green sources of energy which are trending to be cheaper then carbon emitting ones - how much optimisation can we do just to minimise carbon? Its like someone loosing their job, and then thinking "I know, I'll just cut back on spending money" - no, you find an income source (and maybe cut back as well).