Economic growth is not mutually exclusive with sustainability – degrowth jeopardizes billions.

Finally, those who argue for a wait-and-see approach to climate change — that it’s a waste of money to take large actions today for an uncertain risk far in the future — typically discount these future losses at a high rate. That is, whenever one takes an action that has a future cost or benefit, one must assess the present value of these future costs or benefits.

If a dollar 50 years from now is worth the same as a dollar today, one might be motivated to take strong action to prevent a loss; but if a dollar 50 years from now is worth three cents, one wouldn’t.

The discount rate (how we value future costs and benefits relative to today) thus becomes critical. President Donald Trump’s administration has in fact said that one wouldn’t want to spend more than roughly three cents today to prevent a dollar loss in 50 years.

Moral bankruptcy

Future generations just don’t count much. This is morally wrong. But the do-nothing advocates, ignoring all the advances in public economics over the past half-century that have explained otherwise, argue that economic efficiency requires it. They are wrong.

We must take strong action now to avoid the climate disaster toward which the world is heading.

It is a welcome development that so many European leaders are spearheading efforts to ensure that the world is carbon-neutral by 2050. The report of the High-Level Commission on Carbon Prices, which I co-chaired with Nicholas Stern, argued that we could achieve the Paris agreement’s goal of limiting global warming to 2ºC in a way that enhanced living standards: the transition to a green economy could spur innovation and prosperity.

That view sets us apart from those who suggest that the Paris agreement’s goals can be achieved only by stopping economic expansion. I believe that is wrong.

However misguided the obsession with ever-increasing gross domestic product may be, without economic growth, billions of people will remain without inadequate food, housing, clothing, education, and medical care.

But there is ample room to change the quality of growth, to reduce its environmental impact significantly. For example, even without major technological advances, we can achieve carbon neutrality by 2050.