Every invocation of Lord Keynes is an admission of failure. To propose Keynesian solutions to the crises of the 21st century is to ignore three obvious problems. It is hard to mobilise people around old ideas; the flaws exposed in the 70s have not gone away; and, most importantly, they have nothing to say about our gravest predicament: the environmental crisis. Keynesianism works by stimulating consumer demand to promote economic growth. Consumer demand and economic growth are the motors of environmental destruction.