What would the agenda be?
Why do you suppose the Left is the only group pushing this nonsense agenda? What does the Left want? They are constantly in pursuit of creating a Utopia; The Perfect Society, among mankind. In order to accomplish that, they believe Left-led government must have control of all, or most, of the engines that drive society. To do that, they need to tax everything people do, or think of doing. Through unlimited taxation, they hold all the controls over the economy, they believe. Taxing carbon usage is the means through which they believe their agenda can be fueled. Mankind uses more energy every single day and every single year. Look at the idiotic carbon-credits that made Al Gore into a fat slob. He never uses less energy. He buys bigger houses, flies bigger planes and hires fatter massage ladies and then pays money to carbon-credit companies he owns for every BTU over the "prescribed maximum" he uses. He wins both ways. It's ends up being a self-sustaining Ponzi scheme. We never really cut back on energy usage. If Left-led government can find a way to institute carbon taxes, they can tax EVERYTHING without limit.
I assumed you youngsters figured this out for yourselves.