Earth’s atmosphere naturally contains greenhouse gases.
Without them, the world would be way too cold for humans: averaging an icy 0 degrees fahrenheit [-18C] instead of the cozy average of 59 degrees [15C] it is today.
But we are adding extra greenhouse gases, which are causing Earth to heat up and disrupting weather patterns worldwide.
So which of these many gases is heating Earth the most?
So, which gas is heating the Earth the most?
Well, it depends on how you look at it.
The gas that’s trapping the most total heat is water vapor.
One out of every 200 air molecules is an H-2-O, enough to trap about half the heat given off by Earth and help make our planet habitable.
But water vapor isn’t behind Earth’s rising temperatures.
That’s because the atmosphere can only hold so much water vapor, and if you add more, it will just empty out as rain.
However, if something else heats the world up, the atmosphere can soak up more water vapor, which traps even more heat.
Because of this feedback loop, water vapor only amplifies temperature changes caused by other things.
Other things like the greenhouse gases we are adding to the atmosphere.
And ton for ton, the greenhouse gas that raises Earth’s temperature the most is, drumroll please... sulfur hexafluoride [SF6].
It’s one of the heaviest gases, so you can actually float a tinfoil boat on it.
If we released a million tons of it, the weight of just a few skyscrapers, Earth’s surface would heat up by 0.03 degrees fahrenheit [0.028F or 0.015C] over the next 100 years.
That might not like sound like much, but the extra energy would be enough to boil 100 million skyscrapers full of water!
This stuff wouldn’t even be in our atmosphere if we didn’t synthesize it for use as an electrical insulator or as the air in old Nike air max shoes.
Seriously - we used the strongest greenhouse gas ever known, so that we could have see-through-bouncy-shoes.
Fortunately, we haven’t emitted much of it - our atmosphere only has one sulfur hexafluoride for every 100 billion molecules.
But there’s other greenhouse gases we’re adding a lot more of, like methane [CH4], the key ingredient of natural gas.
It leaks into the air when we extract and transport natural gas, but it’s also produced by things like cows and landfills.
If you released three skyscrapers worth of methane into the atmosphere, it would raise the temperature by about 7,000 times less than the same amount of sulfur hexafluoride.
But there’s about 200,000 times more methane - one for every 600,000 air molecules, so it’s one of the gases heating Earth up the most.
But it doesn’t take home the prize.
The gas causing earth to warm the most is, you guessed it… carbon dioxide.
Yup, the gas produced when we burn fossil fuels and chop down trees is famous for a reason.
Per ton, CO2 isn’t very impressive: the same weight of methane would raise the temperature 4 times as much, and sulfur hexafluoride would heat things up 30,000 times as much.
But CO2 still comes out on top for one key reason.
Because there’s a lot of it, and we’re adding a lot more.
Throughout Earth’s history, when CO2 has gone up, temperatures have gone up, and when CO2 has gone down, temperatures have gone down.
Unsurprisingly, by burning fossil fuels, we humans have increased CO2 levels from one out of every 3,600 molecules to one out of every 2,400 molecules.
Remember sulfur hexafluoride?
There’s one sulfur hexafluoride out of every 100 BILLION molecules.
So, yeah, there’s a lot of CO2 in our atmosphere, which is why adding even a little bit more can have such a large effect.
And all the extra carbon-dioxide has caused 70% of the warming over the last 250 years.
So, carbon-dioxide is the winner, methane’s the runner-up, sulfur hexafluoride punches above its weight, and water vapor is just reacting to all of these.
Well, we’re losing.
But the game isn’t over - there’s still time for us to turn things around and beat the greenhouse gases in the end.