Methane vs carbon dioxide is one of the most useful comparisons in climate science. Both trap heat, but they behave very differently over time.
Methane is stronger, for a while
Over 20 years, methane warms the planet 81 to 83 times more than the same amount of carbon dioxide, using IPCC values the US EPA publishes. Over 100 years it is 27 to 30 times more.
That gap exists because methane lasts about a decade in the air on average.
Carbon dioxide stays
Carbon dioxide keeps raising atmospheric levels for thousands of years, the EPA says. It comes mostly from burning fossil fuels, plus things like cement production.
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Where methane comes from
Human methane sources include landfills, livestock and agriculture, coal mining and wastewater treatment, according to the EPA.
The fine print
Which number you use depends on the time horizon. The US emissions inventory still uses older 100-year values.
Why it matters
Cutting methane slows warming quickly, while cutting carbon dioxide protects the long term. Both matter.
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Submit your companySources: US EPA global warming potentials, US EPA importance of methane, US EPA greenhouse gas overview.
Key takeaways on methane vs carbon dioxide
Here is the short version on methane vs carbon dioxide. Over 20 years, methane warms the planet 81 to 83 times more than the same amount of carbon dioxide, using IPCC values the US EPA publishes. That gap exists because methane lasts about a decade in the air on average. Carbon dioxide keeps raising atmospheric levels for thousands of years, the EPA says. Human methane sources include landfills, livestock and agriculture, coal mining and wastewater treatment, according to the EPA. Which number you use depends on the time horizon. Cutting methane slows warming quickly, while cutting carbon dioxide protects the long term. Want a new eco fact every day? Sources: US EPA global warming potentials, US EPA importance of methane, US EPA greenhouse gas overview.
Use these points on methane vs carbon dioxide as a starting point, check the numbers against your own home or business, and share what you learn with someone who can use it.
