Donald Trump, in a book due to hit shelves next week, says “violent climate changes are nothing new.”

“We have even had ice ages,” writes the billionaire candidate. “I just don’t happen to believe they are man-made. I do agree that so-called global climate change is causing us some problems: it’s causing us to waste billions of dollars to develop technologies we don’t need to fulfill our energy needs.”

Trump has been critical of efforts to combat climate change and last week tweeted with regard to a cold front that he “could use a big fat dose of global warming.”