Carbon dioxide (CO2) is just one of many different types of greenhouse gas which contribute to climate change . Although CO2 does make up 76% of greenhouse gas emissions (measured in CO2-eq*), there are two others that we must not forget about :
1) Methane (CH4) is a much more “potent” greenhouse gas than CO2: over 100 years, one methane molecule has the same warming impact as 28 molecules of CO2 . This is because methane is a more powerful greenhouse gas, but lasts on average for only 12 years before breaking down, compared to 5-200 years for CO2 .
Methane accounts for about 17% of CO2-eq emissions . A lot of people think that cows fart methane  – in fact, they burp it ! However, agriculture as a whole is only responsible for about 39% of methane emissions . It may be a surprise to you that energy generation releases a similar amount of methane, at 36% .
2) Nitrous Oxide (N2O) is an even more powerful greenhouse gas than methane – it’s 9x stronger over a 100-year period ! Fortunately, we don’t release that much of it, so it only accounts for about 7% of CO2-eq emissions . 72% of this is from agriculture , primarily from fertilisers and manure .
Whilst altering what we feed cows can reduce CH4 emissions , to reduce emissions more substantially we need to have fewer cows . N2O emissions can be reduced by, for example, using only as much nitrogen fertiliser as a crop will consume , and using alternatives to fertiliser such as leguminous plants (like peas and clover) which take nitrogen out of the air and release it into the soil when they die [14,15].
*CO2-eq = CO2-equivalent emissions: the amount of CO2 that would cause the same amount of warming as a given amount of another greenhouse gas, over a 100-year time span [6,7].
 https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions See: Emissions of other greenhouse gases
 https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions See: Greenhouse gas emissions by gas source
 https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions See: Methane (CH4) emissions by sector
 https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions See: Nitrous oxide (N2O) emissions by sector
 https://www.ipcc.ch/site/assets/uploads/2018/02/AR5_SYR_FINAL_Annexes.pdf See: CO2-equivalent (CO2-eq) emission
 https://www.ghgprotocol.org/sites/default/files/ghgp/Global-Warming-Potential-Values%20%28Feb%2016%202016%29_1.pdf See: GWP values for 100-year time horizon, Fifth Assessment Report (AR5)
 https://archive.ipcc.ch/ipccreports/tar/wg1/016.htm See: table
 https://www.tandfonline.com/doi/full/10.1080/00380768.2012.733869 See: Reducing N fertilization
 https://www.tandfonline.com/doi/full/10.1080/00380768.2012.733869 See: Using biological N fixation to provide N inputs
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