New York Times Public Editor Liz Spayd, the paper’s internal critic of its work, criticized new conservative columnist Bret Stephens on Wednesday for his first op-ed that cast doubt on the “certitude” about climate change.

Spayd wrote on Wednesday that it was “pugnacious” to write on a “flammable” subject for his introductory piece. She said Stephens was “minimizing the serious risk of climate change.”