"At the time, Pruitt said he disagreed with Trump's notion that climate change was a hoax, but he also refused to detail to what extent he believed human industrial activity was the main culprit."

That would be because he said nothing about anthropogenic climate change beyond suggesting that humans might have some impact, although the significance of that impact is still in question.

His full quote:

"I do not believe that climate change is a hoax...Science tells us the climate is changing and human activity in some matter impacts that change. The ability to measure and pursue the degree and the extent of that impact and what to do about it are subject to continuing debate and dialogue."