7 ms·

Could you explain further? How does: > reducing methane emissions won't change a thing, compared to CO2 emissions. Follow from: > once methane emissions rea

by djleni 3y ago

Could you explain further? How does: > reducing methane emissions won't change a thing, compared to CO2 emissions. Follow from: > once methane emissions reach a steady level

xyzzyz 3y ago
Methane in atmosphere today is at 2 ppm, carbon dioxide is at 420 ppm. If methane is 20 times more potent, this implies that atmospheric methane is equivalent to 40 extra ppm of carbon dioxide. If we removed literally all methane from the atmosphere, this would be equivalent to reducing carbon dioxide concentration to 380 ppm. This would bring us back to climate of 2005. By any reasonable measure, climate in 2023 is not significantly different than the climate in 2005 (eg. you’d hardly be able to observe any difference without making a lot of very careful measurements, you wouldn’t “feel” any difference on your own skin). And that’s if we remove literally all methane. Most of the methane in atmosphere is a result of natural processes, not caused by human activity. Thus, if we stop all methane emissions caused by human activity, we can maybe at best slow down climate change by 10 years. In terms of practical effects as felt by human beings, this is accurately described as “won’t change a thing”. Actually, to be more specific, slowing climate change by 10 years won’t make any difference, but stopping all methane emitting activities would be tremendously negative to human flourishing.
- myshpa 3y ago
  > climate in 2023 is not significantly different than the climate in 2005 'Devastating' melt of Greenland, Antarctic ice sheets found https://news.ycombinator.com/item?id=35657570 https://news.ycombinator.com/item?id=35657570 This was here just yesterday. You may not feel it "on your own skin", but Earth does. And what exactly will happen when we'll lose all ice, we simply do not know. We just know it won't be pretty. > stopping all methane emitting activities would be tremendously negative to human flourishing How? I smell bullsh*t.
  - revelio 3y ago
    Antarctic sea ice extent is currently at the same level it was at this time of year in 1980, actually a little higher. Use Charctic to see for yourself: https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/ https://nsidc.org/arcticseaicenews/charctic-interactive-sea-... Arctic sea ice extent is currently tracking the 2010-2020 average. Nothing much is happening in terms of Arctic sea ice extent at the moment and that's been true for a while. There has been a steady decline since 1979, which is the earliest year Charctic shows. But data exists for much longer. This is unfortunately standard for climatology, they truncate many data sets starting at this time and then declare records based on that truncated data set. That's not because nobody cared about the poles before the 80s, people definitely did. Here are some examples. In the 1990 IPCC report, we can see satellite data for the Arctic going back to ~1972 and it shows a huge rise in sea ice extent during that decade ([1], p224, figure 7.20). This data is no longer shown on modern graphs. This 1985 report [2] is by the US Department of Energy "Office of Basic Sciences Carbon Dioxide Research Division", it covers many topics around the construction of global climate models. Figure 5.2 on page 181 shows data on sea ice extents going back to the 1920s, citing Vinnikov et al. It shows a massive fall in sea ice from the 1920s to about 1955, when it turns around and starts climbing again. This data is corroborated by news reports. In the 1920s there were reports about melting ice caps. These were the dustbowl years and the 20s-30s were very hot. But in the middle of the century that turned around and by the mid 1960s the climate had been cooling for decades. The NYT reported [3] that: The United States and the Soviet Union are mounting large‐scale investigations to determine why the Arctic climate is becoming more frigid, why parts of the Arctic sea ice have recently become ominously thicker and whether the extent of that ice cover contributes to the onset of ice ages. Sea ice continued to thicken and by 1975 newspapers were reporting a consensus of experts that the future had a lot more ice in it, claims made credible by the growing Arctic ice conditions [4]: In the last decade, the Arctic ice and snow cap has expanded 12%, and for the first time this century ships making for Iceland ports have been impeded by drifting sea ice [...] Many climatologists see this as evidence that a significant shift in climate is taking place [....] No scientists are predicting a full-scale Ice Age soon, but some predict that in a few decades there might be little ice ages So the Arctic and Antarctic have changed quite a bit in the 20th century. They grow, they shrink, and scientists know this but no longer are willing to show these old datasets because the picture they paint is not a very interesting one. It certainly would not convince anyone that climatology is the key to saving the planet from doom. [1] https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_c... [2] https://www.osti.gov/servlets/purl/5885458 https://www.osti.gov/servlets/purl/5885458 [3] https://www.nytimes.com/1970/07/18/archives/us-and-soviet-press-studies-of-a-colder-arctic-us-and-soviet-press.html?_r=0 https://www.nytimes.com/1970/07/18/archives/us-and-soviet-pr... [4] https://chicagotribune.newspapers.com/search/?query=%20new%20ice%20age&ymd=1975-03-02 https://chicagotribune.newspapers.com/search/?query=%20new%2...
- tpnCC 3y ago
  There is a detail missing in your Calculation. Global Warming Potential of Methane over a 20 year Time period is a bit more than 80 times that of CO2. https://www.epa.gov/ghgemissions/understanding-global-warming-potentials https://www.epa.gov/ghgemissions/understanding-global-warmin... So, redrawing your path by your method, if we remove ALL of the Atmospheric Methane today, we would be reducing GHG concentrations by about 160ppm CO2 equivalent, which takes the overall CO2 concentrations to less than that of pre-industrial levels(280ppm), 260ppm. This negates your conclusion that we would hardly observe ANY difference. If we remove literally all of the Methane today, we would have solved Global warming from the perspective of concentration of Green House gases and will just have to wait and watch for the Global Temperatures to catch up (meaning they will go down).
  - xyzzyz 3y ago
    > Global Warming Potential of Methane over a 20 year Time period is a bit more than 80 times that of CO2. Where in the linked document it says that? Because I do not think it’s true.
    - tpnCC 3y ago
      2nd para beneath the side heading: "Are there alternatives to the 100-year GWP for comparing GHGs?" GWP calculations has been an active area of research for a long time. For instance, if you look up the table beneath the VALUES side-heading in https://en.wikipedia.org/wiki/Global_warming_potential https://en.wikipedia.org/wiki/Global_warming_potential, you would notice that from 1995IPCC to the recent one, Scientists are getting more and more closer to ~80 GWP.
- BlueTemplar 3y ago
  Where did you get the idea that most of the methane is from natural processes ? (Same for people that seem to think that most of anthropogenic ones are from livestock?) Also some of the "natural" causes are suspect now, since they include things like permafrost thaw, which itself is caused by warming...
mlyle 3y ago
If you release the same amount of methane per year for a couple dozen years, the methane reaches a steady state where it has a constant value, but CO2 continues to rise. This is because the methane is being converted to CO2 at a relatively quick clip. The timescale for CO2 is larger-- centuries.
- hkt 3y ago
  Methane - CH4 - degrades to carbon dioxide in the atmosphere. A quick clip, however, it is not: it can take 20 years, during which that single carbon atom yields 20x the global warming potential as part of a methane molecule than it does as part of a carbon dioxide molecule.
  - mlyle 3y ago
    The point is, if emissions are steady state for a bit more than 20 years, the amount of CH4 remains constant. It will be removed from the atmosphere at the same rate it is added. It takes centuries or more for CO2 to reach equilibrium. Indeed, this means most of the warming you get from emitting a molecule of CH4 is after it has decayed to the more stable CO2. Of course, sharp increases in methane are of concern for dynamic effects, from things like permafrost thaw.
  - tremon 3y ago
    it can take 20 years, during which that single carbon atom yields 20x the global warming potential Actually, it's more than that. The 20x global warming potential of CH4 is based on a 100-year average, which is the yardstick unit of measurement in the scientific literature. But as you say, methane degrades in 20 years so its average-20x contribution happens within those 20 years: > The IPCC reports that the global warming potential (GWP) for methane is about 84 in terms of its impact over a 20-year timeframe [..] and 105 times the effect when accounting for aerosol interactions -- from https://en.wikipedia.org/wiki/Atmospheric_methane?useskin=timeless https://en.wikipedia.org/wiki/Atmospheric_methane?useskin=ti...
ackfoobar 3y ago
For a more rigorous approach (of this naiive modelling), here are the differential equations. https://cleantechnica.com/2021/02/06/a-differential-equation-governing-methane-concentration-in-the-atmosphere/ https://cleantechnica.com/2021/02/06/a-differential-equation...

by djleni 3y ago

Could you explain further? How does: > reducing methane emissions won't change a thing, compared to CO2 emissions. Follow from: > once methane emissions reach a steady level

xyzzyz 3y ago

Methane in atmosphere today is at 2 ppm, carbon dioxide is at 420 ppm. If methane is 20 times more potent, this implies that atmospheric methane is equivalent to 40 extra ppm of carbon dioxide. If we removed literally all methane from the atmosphere, this would be equivalent to reducing carbon dioxide concentration to 380 ppm. This would bring us back to climate of 2005. By any reasonable measure, climate in 2023 is not significantly different than the climate in 2005 (eg. you’d hardly be able to observe any difference without making a lot of very careful measurements, you wouldn’t “feel” any difference on your own skin). And that’s if we remove literally all methane. Most of the methane in atmosphere is a result of natural processes, not caused by human activity. Thus, if we stop all methane emissions caused by human activity, we can maybe at best slow down climate change by 10 years. In terms of practical effects as felt by human beings, this is accurately described as “won’t change a thing”. Actually, to be more specific, slowing climate change by 10 years won’t make any difference, but stopping all methane emitting activities would be tremendously negative to human flourishing.

myshpa 3y ago
> climate in 2023 is not significantly different than the climate in 2005 'Devastating' melt of Greenland, Antarctic ice sheets found https://news.ycombinator.com/item?id=35657570 https://news.ycombinator.com/item?id=35657570 This was here just yesterday. You may not feel it "on your own skin", but Earth does. And what exactly will happen when we'll lose all ice, we simply do not know. We just know it won't be pretty. > stopping all methane emitting activities would be tremendously negative to human flourishing How? I smell bullsh*t.
- revelio 3y ago
  Antarctic sea ice extent is currently at the same level it was at this time of year in 1980, actually a little higher. Use Charctic to see for yourself: https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/ https://nsidc.org/arcticseaicenews/charctic-interactive-sea-... Arctic sea ice extent is currently tracking the 2010-2020 average. Nothing much is happening in terms of Arctic sea ice extent at the moment and that's been true for a while. There has been a steady decline since 1979, which is the earliest year Charctic shows. But data exists for much longer. This is unfortunately standard for climatology, they truncate many data sets starting at this time and then declare records based on that truncated data set. That's not because nobody cared about the poles before the 80s, people definitely did. Here are some examples. In the 1990 IPCC report, we can see satellite data for the Arctic going back to ~1972 and it shows a huge rise in sea ice extent during that decade ([1], p224, figure 7.20). This data is no longer shown on modern graphs. This 1985 report [2] is by the US Department of Energy "Office of Basic Sciences Carbon Dioxide Research Division", it covers many topics around the construction of global climate models. Figure 5.2 on page 181 shows data on sea ice extents going back to the 1920s, citing Vinnikov et al. It shows a massive fall in sea ice from the 1920s to about 1955, when it turns around and starts climbing again. This data is corroborated by news reports. In the 1920s there were reports about melting ice caps. These were the dustbowl years and the 20s-30s were very hot. But in the middle of the century that turned around and by the mid 1960s the climate had been cooling for decades. The NYT reported [3] that: The United States and the Soviet Union are mounting large‐scale investigations to determine why the Arctic climate is becoming more frigid, why parts of the Arctic sea ice have recently become ominously thicker and whether the extent of that ice cover contributes to the onset of ice ages. Sea ice continued to thicken and by 1975 newspapers were reporting a consensus of experts that the future had a lot more ice in it, claims made credible by the growing Arctic ice conditions [4]: In the last decade, the Arctic ice and snow cap has expanded 12%, and for the first time this century ships making for Iceland ports have been impeded by drifting sea ice [...] Many climatologists see this as evidence that a significant shift in climate is taking place [....] No scientists are predicting a full-scale Ice Age soon, but some predict that in a few decades there might be little ice ages So the Arctic and Antarctic have changed quite a bit in the 20th century. They grow, they shrink, and scientists know this but no longer are willing to show these old datasets because the picture they paint is not a very interesting one. It certainly would not convince anyone that climatology is the key to saving the planet from doom. [1] https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_c... [2] https://www.osti.gov/servlets/purl/5885458 https://www.osti.gov/servlets/purl/5885458 [3] https://www.nytimes.com/1970/07/18/archives/us-and-soviet-press-studies-of-a-colder-arctic-us-and-soviet-press.html?_r=0 https://www.nytimes.com/1970/07/18/archives/us-and-soviet-pr... [4] https://chicagotribune.newspapers.com/search/?query=%20new%20ice%20age&ymd=1975-03-02 https://chicagotribune.newspapers.com/search/?query=%20new%2...
tpnCC 3y ago
There is a detail missing in your Calculation. Global Warming Potential of Methane over a 20 year Time period is a bit more than 80 times that of CO2. https://www.epa.gov/ghgemissions/understanding-global-warming-potentials https://www.epa.gov/ghgemissions/understanding-global-warmin... So, redrawing your path by your method, if we remove ALL of the Atmospheric Methane today, we would be reducing GHG concentrations by about 160ppm CO2 equivalent, which takes the overall CO2 concentrations to less than that of pre-industrial levels(280ppm), 260ppm. This negates your conclusion that we would hardly observe ANY difference. If we remove literally all of the Methane today, we would have solved Global warming from the perspective of concentration of Green House gases and will just have to wait and watch for the Global Temperatures to catch up (meaning they will go down).
- xyzzyz 3y ago
  > Global Warming Potential of Methane over a 20 year Time period is a bit more than 80 times that of CO2. Where in the linked document it says that? Because I do not think it’s true.
  - tpnCC 3y ago
    2nd para beneath the side heading: "Are there alternatives to the 100-year GWP for comparing GHGs?" GWP calculations has been an active area of research for a long time. For instance, if you look up the table beneath the VALUES side-heading in https://en.wikipedia.org/wiki/Global_warming_potential https://en.wikipedia.org/wiki/Global_warming_potential, you would notice that from 1995IPCC to the recent one, Scientists are getting more and more closer to ~80 GWP.
BlueTemplar 3y ago
Where did you get the idea that most of the methane is from natural processes ? (Same for people that seem to think that most of anthropogenic ones are from livestock?) Also some of the "natural" causes are suspect now, since they include things like permafrost thaw, which itself is caused by warming...

mlyle 3y ago

If you release the same amount of methane per year for a couple dozen years, the methane reaches a steady state where it has a constant value, but CO2 continues to rise. This is because the methane is being converted to CO2 at a relatively quick clip. The timescale for CO2 is larger-- centuries.

hkt 3y ago
Methane - CH4 - degrades to carbon dioxide in the atmosphere. A quick clip, however, it is not: it can take 20 years, during which that single carbon atom yields 20x the global warming potential as part of a methane molecule than it does as part of a carbon dioxide molecule.
- mlyle 3y ago
  The point is, if emissions are steady state for a bit more than 20 years, the amount of CH4 remains constant. It will be removed from the atmosphere at the same rate it is added. It takes centuries or more for CO2 to reach equilibrium. Indeed, this means most of the warming you get from emitting a molecule of CH4 is after it has decayed to the more stable CO2. Of course, sharp increases in methane are of concern for dynamic effects, from things like permafrost thaw.
- tremon 3y ago
  it can take 20 years, during which that single carbon atom yields 20x the global warming potential Actually, it's more than that. The 20x global warming potential of CH4 is based on a 100-year average, which is the yardstick unit of measurement in the scientific literature. But as you say, methane degrades in 20 years so its average-20x contribution happens within those 20 years: > The IPCC reports that the global warming potential (GWP) for methane is about 84 in terms of its impact over a 20-year timeframe [..] and 105 times the effect when accounting for aerosol interactions -- from https://en.wikipedia.org/wiki/Atmospheric_methane?useskin=timeless https://en.wikipedia.org/wiki/Atmospheric_methane?useskin=ti...

ackfoobar 3y ago

For a more rigorous approach (of this naiive modelling), here are the differential equations. https://cleantechnica.com/2021/02/06/a-differential-equation-governing-methane-concentration-in-the-atmosphere/ https://cleantechnica.com/2021/02/06/a-differential-equation...