William Happer. Photo credit: Ken Cedeno/Greenpeace

A chief critic of climate science in the White House is leaving the administration after failing to convince the president to review mainstream research on global warming.

William Happer will leave his post as a senior director on the National Security Council on Friday. Happer's departure comes a day after National Security Adviser John Bolton abruptly resigned amid a dispute with President Trump over holding negotiations with the Taliban. Bolton supported Happer's effort to try to weaken the science backing the National Climate Assessment.

Happer, who is not formally trained in climate science but is an accomplished physicist at Princeton University, was one of the strongest voices against climate science within the administration. He is perhaps the only scientist to brief Trump on climate change research.

Happer has a long history of rejecting established climate science in favor of fringe research. He has claimed that the world is in a carbon dioxide "drought" and that burning more fossil fuels will help humanity by making the planet more habitable, a claim not supported by science. Happer founded the CO2 Coalition, which has sought to expand its influence on Capitol Hill by briefing members of Congress on the benefits of CO2 emissions.

"While your proposed review of alarmist analyses and projections has been delayed, we believe your work in calling attention to the problem of unscientific climate alarmism has reduced the chances of the dramatic increases in energy prices that would arise from the banning of fossil fuels that some have proposed. That in turn will improve and even save lives, both here and abroad," said CO2 Coalition leaders Patrick Moore and Caleb Rossiter in a statement.

Happer's monthslong efforts to conduct an "adversarial" review of climate science was scuttled earlier this summer after facing obstacles within the White House. He was also responsible for blocking written testimony earlier this year from a State Department researcher who warned Congress about the national security dangers of climate change.