There is no doubt that methane (CH4) packs a greenhouse gas punch greater than carbon dioxide (CO2) over the short term making it the low-hanging fruit of climate solutions. Maybe, that’s why talk about CH4 came up often at the recently concluded COP28 in Dubai. But what is missing when describing CH4’s atmospheric impact is its short duration lasting a mere 12 years, and certainly no more than 20. CH4 after becomes CO2 and water vapour. So we still have two potent greenhouse gasses to deal with after the fact.
A kilogram of CO2 entering the atmosphere today will be around for as long as a thousand years. Humans are not putting kilograms but rather megatons of CO2 into the air annually. When compared to volcanic eruptions each year, we produce 60 times more. Our total emissions for 2022 were 36.8 billion tons. That was 0.9% higher than in 2021 but lower than the rate of global economic growth at 3.2%.
CH4 emissions are the least of our greenhouse gas worries. The amount of warming caused by CH4 is short-term because it doesn’t accumulate in the atmosphere for 12 to 20 years. When it vanishes it degrades to become a CO2 problem. Delay CH4 action and its effects will vanish in two decades. Delay acting on CO2, and it will keep accumulating for up to 1,000 years. That’s why every added kilogram of CO2 is the much greater global warming threat.