A rift is emerging among old-guard Democrats and the party’s new arrivals on how the House should address climate change.

The split largely pits generally younger members, such as Rep. Alexandria Ocasio-Cortez (D-N.Y.), who want to create a new climate committee that will pursue a more ambitious climate agenda, and those who say the heavy lifting belongs in the Energy and Commerce Committee.

Incoming Energy and Commerce Committee Chairman Frank Pallone (D-N.J.) finds himself in the uncomfortable...