Roll Call reported Wednesday that U.S. Sen Brian Schatz, a champion of action on climate change, has a chief of staff whose spouse has “substantial holdings” in fossil fuel companies.

The burning of fossil fuels produces greenhouse gas emissions that contribute to global warming.

“The Hawaii Democrat’s chief of staff, Eric Einhorn, lists stock owned by his spouse valued between $168,000 and $445,000 in his financial disclosure across four oil and gas companies: ConocoPhillips, ExxonMobil, Phillips 66 and Enterprise Products Partners LP,” according to the news article. “All of the securities are owned by Einhorn’s spouse and listed under the assets component of Einhorn’s filing with the Senate.”

Roll Call said Schatz and Einhorn did not respond “to repeated requests” for comment.

Civil Beat left an inquiry with Schatz’s office Wednesday that was not immediately returned.

Schatz is chairman of the Senate Democrats’ Special Committee on the Climate Crisis.