The Republican candidate for Pennsylvania governor called an 18-year-old woman "young and naive" after she asked him about campaign contributions from the fossil fuel industry.
Scott Wagner was taking part in a town hall meeting in Montgomery County when he made the comments.
Ross Strauss, a member of the Sunrise Movement, a group that advocates for leaders to reject donations from the fossil fuel industry, questioned his opinions on climate change.
"You've said that climate change is a result of people's body heat and are refusing to take action on the issue" she said.
"Does this have anything to do with the $200,000 that you have taken from the fossil fuel industry?"
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In response, Mr Wagner said he "appreciates her being here" but called her naive - prompting laughter and applause from the crowd.
"Are we here to elect a governor or are we here to elect a scientist?" Wagner asked.
"Okay? I'm here to be the governor. I appreciate and I understand the question."
Mr Wagner added that "climate change is important" but that he was "more interested" in issues such as problems related to sewage.
The exchange was filmed and uploaded to Twitter, prompting the hashtag #YoungAndNaive.
