Representative Alexandria Ocasio-Cortez’s ambitious plan to fight climate change won’t be cheap, according to a Republican-aligned think tank led by a former Congressional Budget Office director.

The so-called Green New Deal may tally between $51 trillion and $93 trillion over 10-years, concludes American Action Forum, which is run by Douglas Holtz-Eakin, who directed the non-partisan CBO from from 2003 to 2005.

That includes between $8.3 trillion and $12.3 trillion to meet the plan’s call to eliminate carbon emissions from the power and transportation sectors and between $42.8 trillion and $80.6 trillion for its economic agenda including providing jobs and health care for all.

“The Green New Deal is clearly very expensive,” the group said in its analysis. “It’s further expansion of the federal government’s role in some of the most basic decisions of daily life, however, would likely have a more lasting and damaging impact than its enormous price tag.”

Backers of the plan say cost of inaction would be more expensive. The resolution itself, released earlier this month by Ocasio-Cortez and Massachusetts Democratic Senator Ed Markey points to a major report on global warming released by the United Nations last October that says catastrophic climate change could cost more than $500 billion annually in lost economic output in the U.S. by 2100.

“Any so-called ‘analysis’ of the #GreenNewDeal that includes artificially inflated numbers that rely on lazy assumptions, incl. about policies that aren’t even in the resolution is bogus,' Markey said on Twitter. “Putting a price on a resolution of principles, not policies, is just Big Oil misinformation.”

Representatives of Ocasio-Cortez, a New York Democrat, didn’t immediately respond to a request for comment.

Republicans have embraced the sweeping plan because they think they can use it to cast Democrats as extreme, take back seats in Congress and possibly keep the White House in 2020.