In the fight against global warming, most innovations have been targeting the greenhouse gas “supervillain” carbon dioxide.

Meanwhile, several “henchmen” gases–some even more potent than CO2–have also been building up in Earth’s atmosphere.

For now, none of these gases is as big a worry as CO2, due to its higher levels in the atmosphere. But if left unchecked, experts warn, these other compounds could create major new climate change battlefronts.