6 ms·

Methane is a lot more powerful of a greenhouse gas than CO2. Turning CO2 from the atmosphere back into CO2 is net even. Turning CO2 into methane is net-bad.

by idoh 6y ago

jniedrauer 6y ago
Since methane is a much more potent greenhouse gas and has a much shorter half-life in the atmosphere compared to CO2, I wonder if it might actually save us. We could render the planet inhospitable early enough to be forced to address the problem without shackling future generations with the fallout like we are doing with CO2.
- dredmorbius 6y ago
  That's ... not great ... but only viable if methane itself doesn't move the climate past a tipping point to runaway greenhouse effects. See "clathrate gun hypothesis", for example. https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
- neckardt 6y ago
  Do you know what the half life of methane in the atmosphere is? I did a search for it but couldn't find it.
  - wahern 6y ago
    9.1 years according to https://en.wikipedia.org/wiki/Atmospheric_methane https://en.wikipedia.org/wiki/Atmospheric_methane
    - nvader 6y ago
      That's funny. https://www.foodsource.org.uk/building-blocks/agricultural-methane-and-its-role-greenhouse-gas https://www.foodsource.org.uk/building-blocks/agricultural-m... claims > it is a relatively short-lived GHG, with emissions breaking down after an average of around 10 years. Looks like someone didn't understand what half-life means, or is being misleading.
      - projektfu 6y ago
        On average, a molecule of methane breaks down in less than 10 years. That is a true interpretation.
        07t15 6y ago
        Half life implies that one half of the mehane molecules decay in that period (or that a single one has a 50% of decaying).
        scaredginger 6y ago
        Depends on what 'average' you mean I guess. It is true for the median of course. However, if the time for an individual molecule to decay is exponentially distributed, you can solve for lambda to find its expected lifetime is 13.1 years. That being said, I'd say this is a less useful interpretation.
  - deleted 6y ago
    [deleted]
- AQuantized 6y ago
  When methane is oxidized it produces carbon dioxide
- Nasrudith 6y ago
  Doesn't it essentially decay to CO2 eventually anyway? In the long term barring it is equivalent to CO2 per carbon molecule. Granted there are Nth order effects of short term heating.
  - imtringued 6y ago
    That CO2 probably came from a cow eating grass so in theory it's not a long term problem either. In practice we are destroying ecosystems faster than they can recover.
belorn 6y ago
How much methane do you get out of 1kg biomass vs how much co2 if you burned it? Methane is indeed a more potent (if shorter lived) greenhouse gas, but one would guess that some amount end up either in the cow or as manure which then act as a natural fertilizer. Natural fertilizer is also an object which commonly get classified as having zero carbon footprint, which again, is a bit odd. The manure has zero carbon if used as natural fertilizer, but the meat from the same cow does not.
- wizzwizz4 6y ago
  Methane produces CO₂ when it "decays" (not really decay, but still), so I think "shorter lived" is misleading.
  - jessaustin 6y ago
    Not true. The main thing that happens is that methane reacts with hydroxyl radicals in the atmosphere to produce water, formaldehyde, and ozone: https://en.wikipedia.org/wiki/Atmospheric_methane#Removal_processes https://en.wikipedia.org/wiki/Atmospheric_methane#Removal_pr...
syl_sau 6y ago
> [I]t would be wrong to assume that the FAO figure is totally scientific. Not only does it rely on evidence which is acknowledged to be uncertain. It is also based on a unit, known as the "CO2 equivalent", which assumes that the emission of one tonne of methane is equivalent to the emission from 25 tonnes of CO2 > [S]ince methane degrades quickly, stable emissions of methane lead to a stable level of methane in the atmosphere and no increase in global temperature. > There is something deeply untrustworthy about a metric which views methane as being many times more harmful than CO2, when only a small reduction in methane emissions is required to stabilise its presence in the atmosphere, whereas a massive reduction in CO2 emissions is required to achieve the same. Source : https://www.thelandmagazine.org.uk/sites/default/files/Is%20Grass-fed%20Guilt-free%20web.pdf https://www.thelandmagazine.org.uk/sites/default/files/Is%20...
- opo 6y ago
  We should obviously be worried about other green house gasses, but methane is a particularly bad green house gas in the short term. >......The IPCC reports that, over a 20-year time frame, methane has a global warming potential of 86 compared to CO2, up from its previous estimate of 72. Given that we are approaching real, irreversible tipping points in the climate system, climate studies should, at the very least, include analyses that use this 20-year time horizon. https://thinkprogress.org/more-bad-news-for-fracking-ipcc-warns-methane-traps-much-more-heat-than-we-thought-9c2badf392df/ https://thinkprogress.org/more-bad-news-for-fracking-ipcc-wa...
- reitzensteinm 6y ago
  This source is trash. The 25 factor comes from the relative impact over the next 100 years for emitting both. It already factors in (relatively) fast breakdown, which the quoted text then attempts to double count. Stabilization isn't some intrinsic goal. I'm sure you can find a coal industry trade publication waving its hands just as well to shift the blame to agriculture.
  - deleted 6y ago
    [deleted]
  - 6y ago

Methane is a lot more powerful of a greenhouse gas than CO2. Turning CO2 from the atmosphere back into CO2 is net even. Turning CO2 into methane is net-bad.

by idoh 6y ago

Methane is a lot more powerful of a greenhouse gas than CO2. Turning CO2 from the atmosphere back into CO2 is net even. Turning CO2 into methane is net-bad.

jniedrauer 6y ago

Since methane is a much more potent greenhouse gas and has a much shorter half-life in the atmosphere compared to CO2, I wonder if it might actually save us. We could render the planet inhospitable early enough to be forced to address the problem without shackling future generations with the fallout like we are doing with CO2.

dredmorbius 6y ago
That's ... not great ... but only viable if methane itself doesn't move the climate past a tipping point to runaway greenhouse effects. See "clathrate gun hypothesis", for example. https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
neckardt 6y ago
Do you know what the half life of methane in the atmosphere is? I did a search for it but couldn't find it.
- wahern 6y ago
  9.1 years according to https://en.wikipedia.org/wiki/Atmospheric_methane https://en.wikipedia.org/wiki/Atmospheric_methane
  - nvader 6y ago
    That's funny. https://www.foodsource.org.uk/building-blocks/agricultural-methane-and-its-role-greenhouse-gas https://www.foodsource.org.uk/building-blocks/agricultural-m... claims > it is a relatively short-lived GHG, with emissions breaking down after an average of around 10 years. Looks like someone didn't understand what half-life means, or is being misleading.
    - projektfu 6y ago
      On average, a molecule of methane breaks down in less than 10 years. That is a true interpretation.
      - 07t15 6y ago
        Half life implies that one half of the mehane molecules decay in that period (or that a single one has a 50% of decaying).
      - scaredginger 6y ago
        Depends on what 'average' you mean I guess. It is true for the median of course. However, if the time for an individual molecule to decay is exponentially distributed, you can solve for lambda to find its expected lifetime is 13.1 years. That being said, I'd say this is a less useful interpretation.
- deleted 6y ago
  [deleted]
AQuantized 6y ago
When methane is oxidized it produces carbon dioxide
Nasrudith 6y ago
Doesn't it essentially decay to CO2 eventually anyway? In the long term barring it is equivalent to CO2 per carbon molecule. Granted there are Nth order effects of short term heating.
- imtringued 6y ago
  That CO2 probably came from a cow eating grass so in theory it's not a long term problem either. In practice we are destroying ecosystems faster than they can recover.

belorn 6y ago

How much methane do you get out of 1kg biomass vs how much co2 if you burned it? Methane is indeed a more potent (if shorter lived) greenhouse gas, but one would guess that some amount end up either in the cow or as manure which then act as a natural fertilizer. Natural fertilizer is also an object which commonly get classified as having zero carbon footprint, which again, is a bit odd. The manure has zero carbon if used as natural fertilizer, but the meat from the same cow does not.

wizzwizz4 6y ago
Methane produces CO₂ when it "decays" (not really decay, but still), so I think "shorter lived" is misleading.
- jessaustin 6y ago
  Not true. The main thing that happens is that methane reacts with hydroxyl radicals in the atmosphere to produce water, formaldehyde, and ozone: https://en.wikipedia.org/wiki/Atmospheric_methane#Removal_processes https://en.wikipedia.org/wiki/Atmospheric_methane#Removal_pr...

syl_sau 6y ago

> [I]t would be wrong to assume that the FAO figure is totally scientific. Not only does it rely on evidence which is acknowledged to be uncertain. It is also based on a unit, known as the "CO2 equivalent", which assumes that the emission of one tonne of methane is equivalent to the emission from 25 tonnes of CO2 > [S]ince methane degrades quickly, stable emissions of methane lead to a stable level of methane in the atmosphere and no increase in global temperature. > There is something deeply untrustworthy about a metric which views methane as being many times more harmful than CO2, when only a small reduction in methane emissions is required to stabilise its presence in the atmosphere, whereas a massive reduction in CO2 emissions is required to achieve the same. Source : https://www.thelandmagazine.org.uk/sites/default/files/Is%20Grass-fed%20Guilt-free%20web.pdf https://www.thelandmagazine.org.uk/sites/default/files/Is%20...

opo 6y ago
We should obviously be worried about other green house gasses, but methane is a particularly bad green house gas in the short term. >......The IPCC reports that, over a 20-year time frame, methane has a global warming potential of 86 compared to CO2, up from its previous estimate of 72. Given that we are approaching real, irreversible tipping points in the climate system, climate studies should, at the very least, include analyses that use this 20-year time horizon. https://thinkprogress.org/more-bad-news-for-fracking-ipcc-warns-methane-traps-much-more-heat-than-we-thought-9c2badf392df/ https://thinkprogress.org/more-bad-news-for-fracking-ipcc-wa...
reitzensteinm 6y ago
This source is trash. The 25 factor comes from the relative impact over the next 100 years for emitting both. It already factors in (relatively) fast breakdown, which the quoted text then attempts to double count. Stabilization isn't some intrinsic goal. I'm sure you can find a coal industry trade publication waving its hands just as well to shift the blame to agriculture.
- deleted 6y ago
  [deleted]
- 6y ago