The Washington Post via Getty Images Billionaires Rebekah Mercer, left, and her father, Robert, at the Heartland Institute’s annual International Conference on Climate Change in March 2017.

The Mercers divvied out a total $15,222,302 to 37 nonprofits in 2017, according to the foundation’s most recently available 990 tax form, which researchers at the Climate Investigations Center shared with HuffPost. That’s down from the approximately $19 million they gave to 44 nonprofits one year earlier. Roughly one-third of all the foundation’s 2017 contributions ― just shy of $5 million ― went to nonprofits that oppose federal regulations targeting greenhouse gas emissions, challenge the scientific consensus that human-caused climate change is an immediate crisis, or promote or funnel cash to denial proponents. “It appears that climate denial is a priority of the Mercer family,” Kert Davies, director of the Climate Investigations Center, told HuffPost. The foundation could not be reached for comment Tuesday. And the CO2 Coalition did not respond to HuffPost’s request for comment. For the second year in a row, the Mercers gave $800,000 to the Heartland Institute, an Illinois-based libertarian think tank that has gained influence during Trump’s tenure and applauded the president’s first year in office as ”a great year for climate realists.” The Mercers have given Heartland a total of $6.7 million since 2008. The foundation also upped its contribution to the Oregon Institute of Science and Medicine, a group founded by Art Robinson, a biochemist floated as a candidate for Trump’s national science adviser and whom FiveThirtyEight dubbed “the grandfather of alt-science.” Robinson used the organization to circulate an infamous and bogus petition that claimed 30,000 scientists had declared there is no evidence of anthropogenic climate change. The Mercers gave the group $500,000 in 2017, up from $200,000 the previous two years. The foundation has given the group nearly $2.2 million since 2005. The Mercers in 2017 also made a first-time donation of $200,000 to the Energy & Environment Legal Institute (formerly the American Tradition Institute), a climate denial group that has received funding from coal companies and repeatedly filed lawsuits in an effort to obtain the personal emails of climate scientists. Foundation money also went to the Media Research Center ($2 million), the Manhattan Institute for Policy Research ($450,000) and the Cato Institute ($300,000). Donors Trust, a conservative group that has funneled millions of dollars to climate denier groups like Heritage and the American Legislative Exchange Council, received $500,000, down from $2.5 million in 2016. Mother Jones called Donors Trust “the dark-money ATM of the right.”

Patrick McMullan via Getty Images Billionaires Robert Mercer and his daughter Rebekah Mercer.