Trump’s argument for withdrawing from Paris agreement contains multi-trillion dollar math error

In a cost-benefit analysis, you’re supposed to analyze the costs and the benefits.

President Donald Trump announced Thursday that the United States would abandon the Paris climate agreement, but his justification for withdrawing was rooted in a false economic claim.

Trump claimed that U.S. commitments under the Paris accord would cost the country’s GDP $3 trillion, but the report he took that estimate from “does not take into account potential benefits from avoided emissions.”

In other words: The study did not account for any benefits of participating in a global plan to avoid the worst effects of climate change. It is a report on climate mitigation that ignores climate change. The report also does not consider the economic benefits to renewable energy industries, nor does it consider the health costs that are associated with fossil fuel pollution.

Frankly, this analysis in line with Trump’s previously articulated positions on climate change and the economy. He does not believe that climate change exists (he has famously called it a hoax perpetuated by China), and he believes that rolling back environmental regulations will help the economy.

These positions fly in the face of established science and history. For starters, climate change is happening. It is happening right now. It is happening because of the rise in greenhouse gas emissions from human activity. In addition, history has shown time and time again that protecting the environment is good for the economy — and for people, who drink water and breathe and also live in houses by the ocean.

The report Trump cited, released by NERA Consulting, is extreme. Even the conservative Heritage Foundation estimated less cost from the Paris agreement than the NERA report.

Meanwhile, non-partisan reports offer dire warnings for not addressing climate change. Earlier this year, researchers at the University of California Berkeley found that “unmitigated, climate change could reduce global GDP by over 20 percent by 2100.”

A 2015 report from Cambridge University’s Judge Business School found that the “present value of the damage caused by human-caused climate change from a moderate warming scenario is an astonishing $400 trillion.”

The same year, a report from Citibank found that not addressing climate change will cost $44 trillion by 2060, while investing in low-carbon energy would save $1.8 trillion through 2040, as compared to a business-as-usual scenario.