This year, the world will spend $US162 billion ($230bn) subsidising renewable energy, propping up inefficient industries and supporting middle-class homeowners to erect solar panels, according to the International Energy Agency. In addition, the Paris Agreement on climate change will cost the world from $US1 trillion to $US2 trillion a year by 2030. Astonishingly, neither of these hugely expensive policies will have any measurable impact on temperatures by the end of the century.