Conservatives’ favorite climate-change denier has died.

John Coleman, a television meteorologist who co-founded the Weather Channel, passed away at the age of 83 on Saturday. He had a six-decade broadcasting career, including a stint as the first weather forecaster on ABC’s Good Morning America, but late in life became known for his crusade against the truth about global warming.

His disbelief in climate change was revealed in 2007, when Coleman noticed NBCUniversal had cut the studio lights during portions of a football game in honor of environmentalism. The stunt angered Coleman, and he wrote a blog post calling global warming “the greatest scam in history. I am amazed, appalled and highly offended by it,” he wrote. “Global Warming: It is a SCAM.”

Coleman was a television meteorologist, not a climatologist; he didn’t even hold a degree in meteorology. But conservative publications began to cite him as if he were an authority on climate science. His biggest break came in 2014, when both CNN and Fox News invited him to speak on his global warming views. Fox New billed him as a “top meteorologist.” On CNN, Coleman proclaimed, “Hello America, there is no global warming.”

Since then, Coleman has been a favorite source for Breitbart, the Daily Caller, and Alex Jones’s InfoWars. In September, Fox News quoted him in an article claiming (falsely) that recent extreme weather events had nothing to with climate change:

It was “an unusual confluence of events,” said Weather Channel founder John Coleman, “but it was certainly not unprecedented.”

The Weather Channel has rebuked its former cofounder. In a statement in 2014, the channel said the “Earth’s climate is indeed warming,” adding, “Researchers overwhelmingly agree that the main cause of recent global warming is the addition of greenhouse gases to the atmosphere (primarily carbon dioxide) through the burning of fossil fuels.” In Coleman’s final tweet, he called this “the most invalid claim ever.”