By Bjorn Lomborg November 21 at 12:57 PM
Bjorn Lomborg is president and founder of the Copenhagen Consensus Center and a visiting professor at Copenhagen Business School.
The election of Donald Trump and Republican majorities in both houses have terrified environmentalists and climate campaigners, who have declared that the next four years will be a “disaster.”
Fear is understandable. We have much to learn about the new administration’s plans. But perhaps surprisingly, what little we know offers some cause for hope.
Even ardent supporters acknowledge that the Paris treaty by itself will do little to rein in global warming. The United Nations estimates that if every country were to make every single promised carbon cut between 2016 and 2030 to the fullest extent and there was no cheating, carbon dioxide emissions would still only be cut by one-hundredth of what is needed to keep temperature rises below 3.6 degrees Fahrenheit (2 degrees Celsius). The Paris treaty’s 2016-2030 pledges would reduce temperature rises around 0.09 degrees Fahrenheit by the end of the century. If maintained throughout the rest of the century, temperature rises would be cut by 0.31 degrees Fahrenheit.
At the same time, these promises will be costly. Trying to cut carbon dioxide, even with an efficient tax, makes cheap energy more expensive — and this slows economic growth.
My calculations using the best peer-reviewed economic models show the cost of the Paris promises – through slower gross domestic product growth from higher energy costs — would reach $1 trillion to $2 trillion every year from 2030. U.S. vows alone — to cut greenhouse-gas emissions 26 percent to 28 percent below 2005 levels by 2025 — would reduce GDP by more than $150 billion annually.
So Trump’s promise to dump Paris will matter very little to temperature rises, and it will stop the pursuit of an expensive dead end.