Top executives from some of the world’s biggest oil companies are testified before Congress on Thursday about the fossil fuel industry’s alleged efforts to mislead the public about climate change.

Lawmakers on the House Committee on Oversight and Reform brought in executives from ExxonMobil, BP, Chevron and Royal Dutch Shell to grill them about what Democrats say is their decades-long history of sowing doubt about the effects their products are having on Earth’s temperature and the stability of its climate system.