Last and first men jumps to what would seem to many an extreme position in order to make sure the full problems is solved, if it is solved at all. Even if we managed to stop capitalist climate change we would confront all sorts of other problems. In general the issue of communism must be rescued from marxism and bolshevism, without becoming false compromises. Once we see that a generation of climate activism has not changed anything very much, nor forestalled the onset of potentially disastrous levels of temperature rise (6 degrees???), we are forced to consider the idea of a system-wide global change, however hard, however improbable at first.
A new form of economic theory is one starting point. Don’t listen to sophistical economists on the subject: if marginalist economics is illusory, we can be sure it is hiding something simple as an alternative.