Twiddling our thumbs on climate change could cost $20 trillion a year by 2100

Failure to fight global warming could cost $20 trillion a year by the end of the century, says a new study from Tufts University — and that doesn’t include costs of biodiversity loss or unpredictable events like the shutdown of the Gulf Stream. That enormous figure — representing the cost of doing nothing while the global temperature rises about 7 degrees Fahrenheit — is equal to about 6 to 8 percent of projected world economic output at century’s end. But relatively moderate spending now of about $3 trillion a year to curb emissions could avoid $12 trillion in annual damages, and could keep warming to about 3.5 degrees F, thus avoiding the worst of climate chaos. That sounds like a smart investment, says Friends of the Earth, which commissioned the study. According to separate research by oil giant Shell, finding solutions to global warming could create $58 billion in annual business for British companies alone. “The cost-benefit equation of action to tackle climate change is favorable,” says Shell Chair James Smith.