Washington (CNN) Prominent climate change skeptics, including one who now advises the Trump White House, sent NASA Administrator Jim Bridenstine a chain of emails last year blasting his evolving views on climate change and humanity's role in it.

Bridenstine was copied on the emails, where it was suggested he "sidestep" the climate issue in the future.

"I fully believe and know that the climate is changing. I also know that we, human beings, are contributing to it in a major way," Bridenstine said a May 2018 meeting with NASA employees.

President Donald Trump has described climate change as a "hoax" and the administration has sought to roll back regulations of greenhouse gases. Man-made increases of those gases are causing a rise in global temperatures and associated impacts such as sea-level rise.

"[H]ow Bridenstein (sic) or anyone else can say that humans are a major cause of warming is a puzzle to me," the email chain between William Happer , who now counsels national security adviser John Bolton on climate change issues, and Thomas Wysmuller of the conservative Heartland Institute, states.

Read More