I t is foolhardy and foolish for world leaders to stay fixated on Paris – not only will it likely falter, but it will be hugely costly and do almost nothing to fix climate change.

Hours before Donald Trump announced that the US would be quitting the Paris carbon-cutting treaty, UN Secretary General António Guterres took to the President’s preferred medium, Twitter, to declare that climate action is “unstoppable”.

The clear message, reinforced by leaders from the European Union and China, is that the rest of the world will continue with the Paris Treaty without US involvement. Their resolve is quickly going to smash into three incontrovertible truths.

First, the Paris Treaty will be the most expensive global agreement in world history. Cutting emissions without affordable, effective replacements for fossil fuel means more expensive power and less economic growth.Calculations using the best peer-reviewed economic models show the global price tag of all the Paris Treaty promises –through slower GDP growth from higher energy costs – would reach $1 trillion to $2 trillion every year from 2030. Without US involvement, the rest of the world must cough up between $800 billion and $1.6 trillion annually.