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I strongly agree with this take. I've been working on a paper comparing the effects of the Anthropocene to mega catastrophes in the geologically recent past.

I strongly agree with this take. I've been working on a paper comparing the effects of the Anthropocene to mega catastrophes in the geologically recent past. In addition to the Younger Dryas Impact (12kya), there's the Oruani (26kya) and Mt Toba (77kya) eruptions. From my calculations, it seems the climate change from each of these dwarfs any actions humans are currently capable of, namely petrocarbon burning and also total nuclear war. I'm also critical of the account given to these events in the IPCC reports. It seems unbelievable to me that the climate change debate isn't considering these more, so I'm still debugging the numbers and research. But happy to take comments from anyone who's interested! https://docs.google.com/document/d/1yo9yHMfEnEepefDCRdar-B-4DhlPCifnQF1IOv8TcDg/edit# https://docs.google.com/document/d/1yo9yHMfEnEepefDCRdar-B-4...

ncmncm 6y ago
Previous catastrophes did not vent the millions of tons of hydrofluorocarbons into the atmosphere that we will, that break down into a greenhouse gas thousands of times as potent as CO2. (We thought switching from CFCs to HFCs would save us. Joke's on us!) The total of HFCs currently in circulation, eventually leaked or vented, will produce as much greenhouse effect as all the CO2 currently in the atmosphere. (A sharp minority of the responsible people collect it for disposal.) So, it's not just CO2. The US is supposed to switch from HFCs to something else around 2024. A lot of companies are switching to propane refrigerant ahead of time because it's cheaper, and worry about it igniting has dissipated, vs. looming ecological catastrophe. BTW, to my knowledge the Greenland structure has not been reliably dated, nor even confirmed to be a bolide crater (although it seems like one). YD bolide impact seems pretty secure, though. Temperature change might be a relatively minor effect of the CO2 concentration peak. Ocean acidification causing a collapse at the base of the food web, as marine animals become unable to fix calcium to make shells, might be more important.
- pmayrgundter 6y ago
  It's not clear to me that volcanoes don't release both CFCs and HFCs. Do you have a citation? I'm looking at the wiki articles, and then at the related chem articles about HFC types and synthesis. I'm not a chemist, but a quick look around makes me think the known CFC, fluorocarbon and halomethanes in volcanic gases would suggest the same or similar compounds as in our engineering uses. https://en.wikipedia.org/wiki/Volcanic_gas#Composition https://en.wikipedia.org/wiki/Volcanic_gas#Composition https://en.wikipedia.org/wiki/Halomethane https://en.wikipedia.org/wiki/Halomethane https://en.wikipedia.org/wiki/Hydrofluorocarbon https://en.wikipedia.org/wiki/Hydrofluorocarbon On Hiawatha, agreed it's not yet dated, though it is recent: "The age of the crater is presently unknown, but an impact sometime during the Pleistocene is consistent with presently available geological and geophysical data." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/ They also raise the possibility that some of the radar returns indicate it's still hot in the center of the impact area(!). If so, it's probably one of the YDB impactors. Btw, there's been another one discovered near it: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL078126 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL07.... They say they don't think it's related, though it does still have large features that should have been eroded away if it were really old. We'll see!
ancientworldnow 6y ago
The earth is warming at a rate of four Hiroshima bombs per second [1] primarily because of human actions. I haven't read your document but it sounds like you're grossly underestimating our energy output. [1] https://archive.thinkprogress.org/earths-rate-of-global-warming-is-400-000-hiroshima-bombs-a-day-44689384fef9/ https://archive.thinkprogress.org/earths-rate-of-global-warm...
- samatman 6y ago
  Regarding Toba, Le Wik has this to say: The erupted mass was, at the very least, 12 times greater than that of the largest volcanic eruption in recent history, the 1815 eruption of Mount Tambora in Indonesia, which caused the 1816 "Year Without a Summer" in the Northern Hemisphere.[8] Toba's erupted mass deposited an ash layer of about 15 centimetres (5.9 in) thick over the whole of South Asia. A blanket of volcanic ash was also deposited over the Indian Ocean, the Arabian Sea, and the South China Sea.[9] Deep-sea cores retrieved from the South China Sea have extended the known reach of the eruption, suggesting that the 2,800 km³ calculation of the erupted mass is a minimum value or even an underestimate.[10] Based on new methods (crystal concentration and exponential), the Lake Toba Caldera possibly erupted as much as 3,200 km³ of ignimbrite and co-ignimbrite. I think its more likely your cursory dismissal which is failing to appreciate the magnitude of this event, than that the person who is actually crunching the numbers is getting it wrong. But what do I know?
  - pmayrgundter 6y ago
    I spent some more time on this and now have a comparison table, with citations in my doc. V8 volcanoes still look more energetic and happen once every million years. @ancientworldnow, I'd note that the figure of 4 Hiroshimas/second is the measure of Global Warming, not of human energy production. Hansen acknowledges this in the linked TED talk from your citation, at about 7 minutes in ("it's about 20 times greater than all the energy used by humanity"). To get a sense of comparison, I also found that is the total energy released by a hurricane (note, ~99% hurricane energy is released in evaporation, the kinetic is ~1%): Mt. Toba 74kya, VEI 8/M8.8 eruption energy: 1e21-1e22 Joules Global Warming: 7.88e21 Joules/year A hurricane: 1e21 J Hiawatha Crater impact energy: 3e21 J Human energy production 2013: 5.7e20 J/year Mt. Tambora 1815, VEI 7 eruption energy: 1.3e20 J Largest earthquakes 2: 1e19 J Mt. Pinatubo 1991, Krakatoa 1883; VEI 6 eruption energy: 8.3e17 J Mt. St. Helens 1980, VEI 4 eruption energy: 1e17 J World nuclear weapon stockpile yield (estimate 2, extrapolated from USA): ~1e16 J United States nuclear weapon stockpile yield 2020: 1.37e15 J M8 Volcanoes once every million years, but M7 yield > 10x more energy over time: “Analysis of this dataset indicates that eruptions of size M8 and larger have occurred with minimum frequency of 1.4 events/Ma… While the effect of any individual M8 or larger eruption is considerable, the time-averaged impact (i.e., erupted mass*frequency) of the very largest eruptions is small, due to their rarity. The long-term, time-averaged erupted mass flux from magnitude 8 and 9 eruptions is ~10–100 times less than for M7 eruptions; the time-averaged mass eruption rate from M7 eruptions is 9,500 kg s1, whereas for M8 and M9 eruptions it is ~70– 1,000 kg s1. Comparison of the energy release by volcanic eruptions with that due to asteroid impacts suggests that on timescales of <100,000 years, explosive volcanic eruptions are considerably more frequent than impacts of similar energy yield. This has important implications for understanding the risk of extreme events.” - Mason et al2
neffy 6y ago
I think you're right, if you take the extreme events that have happened on this planet - and arguably the ice ages themselves also belong there, human activities haven't yet produced anything of that magnitude. The question is how many more years do you want to give it until we do. These are huge slow systems we are looking at, at the point there is clear evidence around us that disaster is on the horizon, it is already several decades too late to do anything about it.

ncmncm 6y ago

Previous catastrophes did not vent the millions of tons of hydrofluorocarbons into the atmosphere that we will, that break down into a greenhouse gas thousands of times as potent as CO2. (We thought switching from CFCs to HFCs would save us. Joke's on us!) The total of HFCs currently in circulation, eventually leaked or vented, will produce as much greenhouse effect as all the CO2 currently in the atmosphere. (A sharp minority of the responsible people collect it for disposal.) So, it's not just CO2. The US is supposed to switch from HFCs to something else around 2024. A lot of companies are switching to propane refrigerant ahead of time because it's cheaper, and worry about it igniting has dissipated, vs. looming ecological catastrophe. BTW, to my knowledge the Greenland structure has not been reliably dated, nor even confirmed to be a bolide crater (although it seems like one). YD bolide impact seems pretty secure, though. Temperature change might be a relatively minor effect of the CO2 concentration peak. Ocean acidification causing a collapse at the base of the food web, as marine animals become unable to fix calcium to make shells, might be more important.

pmayrgundter 6y ago
It's not clear to me that volcanoes don't release both CFCs and HFCs. Do you have a citation? I'm looking at the wiki articles, and then at the related chem articles about HFC types and synthesis. I'm not a chemist, but a quick look around makes me think the known CFC, fluorocarbon and halomethanes in volcanic gases would suggest the same or similar compounds as in our engineering uses. https://en.wikipedia.org/wiki/Volcanic_gas#Composition https://en.wikipedia.org/wiki/Volcanic_gas#Composition https://en.wikipedia.org/wiki/Halomethane https://en.wikipedia.org/wiki/Halomethane https://en.wikipedia.org/wiki/Hydrofluorocarbon https://en.wikipedia.org/wiki/Hydrofluorocarbon On Hiawatha, agreed it's not yet dated, though it is recent: "The age of the crater is presently unknown, but an impact sometime during the Pleistocene is consistent with presently available geological and geophysical data." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/ They also raise the possibility that some of the radar returns indicate it's still hot in the center of the impact area(!). If so, it's probably one of the YDB impactors. Btw, there's been another one discovered near it: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL078126 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL07.... They say they don't think it's related, though it does still have large features that should have been eroded away if it were really old. We'll see!

ancientworldnow 6y ago

The earth is warming at a rate of four Hiroshima bombs per second [1] primarily because of human actions. I haven't read your document but it sounds like you're grossly underestimating our energy output. [1] https://archive.thinkprogress.org/earths-rate-of-global-warming-is-400-000-hiroshima-bombs-a-day-44689384fef9/ https://archive.thinkprogress.org/earths-rate-of-global-warm...

samatman 6y ago
Regarding Toba, Le Wik has this to say: The erupted mass was, at the very least, 12 times greater than that of the largest volcanic eruption in recent history, the 1815 eruption of Mount Tambora in Indonesia, which caused the 1816 "Year Without a Summer" in the Northern Hemisphere.[8] Toba's erupted mass deposited an ash layer of about 15 centimetres (5.9 in) thick over the whole of South Asia. A blanket of volcanic ash was also deposited over the Indian Ocean, the Arabian Sea, and the South China Sea.[9] Deep-sea cores retrieved from the South China Sea have extended the known reach of the eruption, suggesting that the 2,800 km³ calculation of the erupted mass is a minimum value or even an underestimate.[10] Based on new methods (crystal concentration and exponential), the Lake Toba Caldera possibly erupted as much as 3,200 km³ of ignimbrite and co-ignimbrite. I think its more likely your cursory dismissal which is failing to appreciate the magnitude of this event, than that the person who is actually crunching the numbers is getting it wrong. But what do I know?
- pmayrgundter 6y ago
  I spent some more time on this and now have a comparison table, with citations in my doc. V8 volcanoes still look more energetic and happen once every million years. @ancientworldnow, I'd note that the figure of 4 Hiroshimas/second is the measure of Global Warming, not of human energy production. Hansen acknowledges this in the linked TED talk from your citation, at about 7 minutes in ("it's about 20 times greater than all the energy used by humanity"). To get a sense of comparison, I also found that is the total energy released by a hurricane (note, ~99% hurricane energy is released in evaporation, the kinetic is ~1%): Mt. Toba 74kya, VEI 8/M8.8 eruption energy: 1e21-1e22 Joules Global Warming: 7.88e21 Joules/year A hurricane: 1e21 J Hiawatha Crater impact energy: 3e21 J Human energy production 2013: 5.7e20 J/year Mt. Tambora 1815, VEI 7 eruption energy: 1.3e20 J Largest earthquakes 2: 1e19 J Mt. Pinatubo 1991, Krakatoa 1883; VEI 6 eruption energy: 8.3e17 J Mt. St. Helens 1980, VEI 4 eruption energy: 1e17 J World nuclear weapon stockpile yield (estimate 2, extrapolated from USA): ~1e16 J United States nuclear weapon stockpile yield 2020: 1.37e15 J M8 Volcanoes once every million years, but M7 yield > 10x more energy over time: “Analysis of this dataset indicates that eruptions of size M8 and larger have occurred with minimum frequency of 1.4 events/Ma… While the effect of any individual M8 or larger eruption is considerable, the time-averaged impact (i.e., erupted mass*frequency) of the very largest eruptions is small, due to their rarity. The long-term, time-averaged erupted mass flux from magnitude 8 and 9 eruptions is ~10–100 times less than for M7 eruptions; the time-averaged mass eruption rate from M7 eruptions is 9,500 kg s1, whereas for M8 and M9 eruptions it is ~70– 1,000 kg s1. Comparison of the energy release by volcanic eruptions with that due to asteroid impacts suggests that on timescales of <100,000 years, explosive volcanic eruptions are considerably more frequent than impacts of similar energy yield. This has important implications for understanding the risk of extreme events.” - Mason et al2

neffy 6y ago

I think you're right, if you take the extreme events that have happened on this planet - and arguably the ice ages themselves also belong there, human activities haven't yet produced anything of that magnitude. The question is how many more years do you want to give it until we do. These are huge slow systems we are looking at, at the point there is clear evidence around us that disaster is on the horizon, it is already several decades too late to do anything about it.