A brief guide to the greenhouse gases driving climate change

Greenhouse gases are those that trap heat in the atmosphere. SF₆ and other fluorinated gases can be thousands of times more powerful at warming the planet than carbon dioxide, and yet, because they tend to escape in relatively small amounts, we hardly ever talk about them. Taken alone, their effects might be minor compared with those of carbon dioxide, but together, these gases add significantly to the challenge of addressing climate change. 

For more on the specifics of sulfur hexafluoride, check out my story from earlier this week. And in the meantime, here’s a quick cheat sheet on the most important greenhouse gases you need to know about. 

Carbon dioxide: The leading actor

I couldn’t in good conscience put together a list of greenhouse gases and not at least mention the big one. Human activities released 37.4 billion tons of carbon dioxide into the atmosphere in 2023. It’s the most abundant greenhouse gas we emit, and the most significant one driving climate change. 

It’s difficult to nail down exactly how long CO₂ stays in the atmosphere, since the gas participates in a global carbon cycle—some will immediately be soaked up by oceans, forests, or other ecosystems, while the rest lingers in the atmosphere for centuries. 

Carbon dioxide comes from nearly every corner of our economy—the largest source is power plants, followed by transportation and then industrial activities. 

Methane: The flash in the pan

Methane is also a powerful contributor to climate change, making up about 30% of the warming we’ve experienced to date, even though carbon dioxide is roughly 200 times more abundant in the atmosphere.