Washington (CNN) NASA Administrator Jim Bridenstine sparred with Sen. Brian Schatz during his confirmation hearing last fall over whether human activity was a contributor to or the primary cause of climate change.

Now Schatz is praising Bridenstine for what the Hawaii Democrat described as "an act of common sense and courage" after the administrator said he now accepts that humans are primarily responsible for climate change.

During a Senate appropriations subcommittee hearing Wednesday, Schatz asked Bridenstine whether he believed that greenhouse gases were the primary cause of climate change.

Bridenstine, a former Oklahoma Republican congressman, replied that he did.

"The National Climate Assessment that includes NASA, and it includes the Department of Energy and it includes NOAA, has clearly stated it is extremely likely -- is the language they use -- that human activity is the dominant cause of global warming," Bridenstine said.

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