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Yeah, but that is mostly beside the point. In pure carbon, anthropogenic CO2 emissions are about 12 GtC/year, and CH4 emissions (from fossil fuel, agriculture,
by sampo 4y ago
Yeah, but that is mostly beside the point. In pure carbon, anthropogenic CO2 emissions are about 12 GtC/year, and CH4 emissions (from fossil fuel, agriculture, waste) about 0.27 GtC/year. So CO2 from methane emissions is only 2% of all CO2 emissions.
- giantrobot 4y agoMethane is like 80x worse than CO2 in terms of greenhouse effect. So that 0.27Gt of CH4 has the GHG effect of 22Gt of CO2. When it decomposes to CO2 it then still has the greenhouse effect of gigs tons of CO2.
- virgildotcodes 4y agoAssuming these numbers are correct - given that CH4 traps 80x more heat than CO2 over the first 20 years[1], it would be the equivalent of adding another 21.6 GtC per year for those first 20 years. Over the span of 100 years, that CH4 degrades into CO2 but still ends up trapping 25x more heat than the same amount of CO2 emitted at the outset, resulting in the same impact as releasing another 6.75 GtC/year over the next century. Nothing to dismiss, especially because that extra boost to heating in those first 20 years could be the difference between us hitting various tipping points, like melting permafrost and releasing yet another 185 GtC[2] into the atmosphere, and not. [1]https://climate.mit.edu/ask-mit/why-do-we-compare-methane-carbon-dioxide-over-100-year-timeframe-are-we-underrating https://climate.mit.edu/ask-mit/why-do-we-compare-methane-ca... [2]https://www.carbonbrief.org/imminent-tipping-point-threatening-europes-permafrost-peatlands/ https://www.carbonbrief.org/imminent-tipping-point-threateni...