Sen. Chris Coons, D-Del., admitted Tuesday he was surprised that secretary of state nominee Rex Tillerson supports a carbon tax, given President-elect Trump’s criticism of President Obama’s climate change policies.

“My understanding is that [the Exxon Mobil CEO] advocated for a carbon tax and for market mechanisms to address climate change as the most even-handed way — a revenue-neutral carbon tax — as the most effective and even-handed way to tackle climate change,” Coons told reporters Tuesday in the Senate. “That’s intriguing. I didn’t expect that from an oil-and-gas man.”