"we need to change the economic system and underlying financial system."
And.....the chances of that happening round to zero. Wars are fought over this topic, with tens of thousands of causalities.
The reason why anti-science climate deniers exist is because they reasoned, thirty years ago, that concern over climate matters could go in one of two directions, and the most probable of those two directions was that anti-capitalists would form common cause with environmentalists and use climate concerns to subvert capitalism.
So, instead of trying to steer climate policies in the other of those two directions (that which addresses climate policy at the local and individual levels rather than top-down, authoritarian government mandates), a battle which they reasoned they could lose, they decided to head the entire policy debate off at the pass by denying that climate issues even exist.
Which has kept the two sides at stalemate for thirty years. Avoidably.