7 ms·

> The fire creates the storm, and then the storm creates lightning, which can cause more fires > That runaway feedback is the dangerous part. This is the seco

> The fire creates the storm, and then the storm creates lightning, which can cause more fires > That runaway feedback is the dangerous part. This is the second year I've heard the term pyrocumulus/pyrocumulonimbus so prominently in relation to the Sierras in California. If this happens more frequently, we might lose a lot of forest. It seems like that would accelerate the effects of climate change... which would also amplify the frequency of these events.

bamboozled 5y ago
Yes, this is what will happen in many areas.
RadioactiveMan 5y ago
Would we really lose them? My understanding is that, after a fire, a forest experiences very rich growth, especially of plants that don't grow much under the shade of old trees, which are good food and cover for many animals.
- jszymborski 5y ago
  Right, but it takes ages for forests to grow, and that period is plenty time for CO2 emissions to run-away from us.
  - tomc1985 5y ago
    There is a small but growing movement towards controlled burns of forests and such because not burning for long enough creates conditions that make wildfires even bigger and harder to stop. If you can rotate between enough zones over time the burned area can regrow fully. It has been said that part of the reason wildfires get so bad now is because we do not let them partake in their normal cycle of burning down occasionally.
    - bawolff 5y ago
      What do you mean small but growing? This is mainstream e.g. https://www2.gov.bc.ca/gov/content/safety/wildfire-status/prevention/vegetation-and-fuel-management/prescribed-burning https://www2.gov.bc.ca/gov/content/safety/wildfire-status/pr...
      - s1artibartfast 5y ago
        It isn't implemented anywhere near the natural level, let alone the required levels to offset 150 years of suppression.
  - dredmorbius 5y ago
    I'll lead with: yes, these fires are devastating. Ironically, if topsoil isn't sterilised or washed away, and both can and do happen with the mega fires we've been seeing, fresh growth after a wildfire can be stunningly quick. A mature forest is self-limited by the existing mature growth --- juvenile trees simply cannot get sufficient light. If mature growth is cleared, the juveniles grow quickly. It's still a slow process, and we're talking about ~30--50 years for a redwood to hit 100' or so (coast redwoods can grow to over 380' / 115m, giant sequoia are more massive but not quite so tall --- 286' / 87m. As carbon sinks, redwood, doug fir, ponderosa, and other trees common to the western coastal ranges, Sierra, and Cascades are not insignificant, but probably pale compared to bogs, swamps, wetlands, mangroves, and tropical rainforests. Thats' a general sense, though I don't have solid numbers at hand. Burning down the Sierra, Cascades, and Rockies isn't going to do us any favours. But it's still relatively modest. I'd be more concerned about tundra / permafrost melting and release, bog fires, wetlands loss, and rainforest. Unfortunately we'll likely see all of that as well.
    - jszymborski 5y ago
      Well, I learned a lot today! Thanks for the free education :)
- micro_cam 5y ago
  These current fires are much more destructive because of a combination of the extreme conditions, a dense under story from fire suppression and lots of standing dead wood from beetle kill etc. So ideally for a forest you would have small fires come through regularly and clean up the under brush but leave a fair number of large mature trees standing leading to open fire resistant mature forest. With these large super destructive fires that wipe out everything you get slower reseeding which can let invasives weeds take hold. And you get dense stands of young trees and brush which are less fire resistant than mature forests. Partial solutions include controlled burns in the wet season and thinning where you shoot to leave the large mature trees but reduce fuels. (This isn't always commercially viable though developing wood products that can be made from small trees or even brush harvested during thinning is an interesting area.)
  - Arrath 5y ago
    > With these large super destructive fires that wipe out everything you get slower reseeding which can let invasives weeds take hold. And you get dense stands of young trees and brush which are less fire resistant than mature forests. If you're real unlucky an above average wet season after a super destructive fire will cause untold amounts of topsoil erosion and damage, impacting the follow on reseeding even more.
    - micro_cam 5y ago
      Oh yeah, full on mud slides are quite common after a fire.
  - bawolff 5y ago
    Are current fires actually much more destructive? https://cwfis.cfs.nrcan.gc.ca/data/charts/NFD_NFDB_comparison_stats_chart.png https://cwfis.cfs.nrcan.gc.ca/data/charts/NFD_NFDB_compariso... seems to suggest that the average year is getting worse but really big outliers are getting rarer. https://www.google.com/amp/s/globalnews.ca/news/8045796/canada-wildfires-yearly-trends/amp/ https://www.google.com/amp/s/globalnews.ca/news/8045796/cana... suggests we have a higher number than normal but below average in total area burnt.
- coliveira 5y ago
  Yes, that would be the case in normal conditions. Not if huge swaths of the forest are destroyed annually.
- pvaldes 5y ago
  > Would we really lose them? Yes, at least without human intervention. The stress concept in ecology predicts more biodiversity at minor events, but much less at large-scale global events. A pinch of disturbance is good for the life beings. This levels of disturbance at the same time in the North and in Brazil are not good.
slownews45 5y ago
There was much much more fire in the past. California is a terrible example if you want to show natural / historic rates of fire. I'm sure native american's burned huge quantities for lots of reasons as well?
- beowulfey 5y ago
  If you want to make statements like this on HN, please back them up with sources.
  - hodgesrm 5y ago
    The paper cited below estimates that 1.8M hectares burned annually in California before 1800 (over 4M acres). [1] That's about how much burned in 2020. [2] [1] https://nature.berkeley.edu/stephenslab/wp-content/uploads/2015/04/Stephens-et-al.-CA-fire-area-FEM-2007.pdf https://nature.berkeley.edu/stephenslab/wp-content/uploads/2... [2] https://en.wikipedia.org/wiki/2020_California_wildfires https://en.wikipedia.org/wiki/2020_California_wildfires Edit: clarity
    - dragonsky67 5y ago
      I'm wondering what type of fires these were. There is a vast difference between a forest crown wild fire, and a cooler one that mostly works burning undergrowth and leaf litter. Still fires, still covering the same amount of ground, one can destroy the forest and anything else in the vicinity, the other can help plants germinate and seeds the forest for the next period of growth.
      - s1artibartfast 5y ago
        They were low intensity fires. Many areas burned every 3 years on average before 1850. These same areas haven't experienced a fire since 1900
      - slownews45 5y ago
        You only get high intensity fires if you have too LITTLE fire, not too much. If you have annual burning it's not going to be high intensity. That said, even high intensity fires have pretty impressive recovery. Do you want to give me a high intensity fire from 5+ years ago? I can then show you the recovery if you want.
BurningFrog 5y ago
Burning forests will increase the CO₂ level, but since there is no "local global warming", the effect is diluted over the whole planet, and I'd be very surprised if the feedback effect is at all significant.
- coliveira 5y ago
  Except that is not happening only in the NW. From Australia to Siberia to the Amazon forest, you see the same pattern.
- cryptoz 5y ago
  > since there is no "local global warming" There is, though. Climate change has different impacts depending on where you are. Some areas are rising in temperature much much faster than others. The arctic is a good example of 'local global warming'. > I'd be very surprised if the feedback effect is at all significant Prepare to be surprised. Even if there are 1000 factors each of them only contributing .1% to the total, it is still the case that each one of the 1000 factors is significant.
  - Denvercoder9 5y ago
    You're right that some areas are impacted more by climate change, but that's not correlated with the areas that emit more CO2. In other words: local emissions don't determine local warming.
    - cryptoz 5y ago
      I really don't think that's true, or at least, it's not as clear-cut as you are asserting. There is at least healthy debate about the issue and it is definitely not a closed case of "local emissions don't determine local warming". As far as I can tell, local emissions do relate to increased local warming. Here's a source https://www.scientificamerican.com/article/can-carbon-dioxide-domes-affect-health/ https://www.scientificamerican.com/article/can-carbon-dioxid...
ErikVandeWater 5y ago
This made me go back and read about cloud seeding. I'm surprised at how controversial its efficacy is. It seems it would be simple to set up in a lab conditions that would be favorable for a cloud seeding mission in the real world (conditions where the air is moist but not precipitating). Insert the silver iodide and see how much of the water in the air condenses. Multiply it out to see how much silver iodide you would need to substantially increase rain. Test in different conditions to see the operating window for cloud seeding is. It should be noted that the benefit of cloud seeding is not necessarily increasing total rainfall in a region, but controlling where that rainfall occurs.
- dxbydt 5y ago
  You don't need silver iodide & suchlike. You can build a simple catapult & fire drones into the cloud. The drone delivers an electric charge to the cloud. This dislodges the water which falls down as rain. This is already routine[1] [1] https://www.bbc.com/news/technology-56428984 https://www.bbc.com/news/technology-56428984
  - ErikVandeWater 5y ago
    The article says they are in the proof of concept stage.
    - dxbydt 5y ago
      that bbc report is from march. here's a recent update from last week. it actually works very well - lots of rain. https://www.usatoday.com/story/news/world/2021/07/21/cloud-seeding-uae-artificial-rain-drones-electricity/8040330002/ https://www.usatoday.com/story/news/world/2021/07/21/cloud-s... https://www.newsweek.com/dubai-creates-fake-rain-using-drones-battle-122-degree-heat-1611887 https://www.newsweek.com/dubai-creates-fake-rain-using-drone...
jussij 5y ago
Undoubtedly more of these positive feedback loops will identify themselves going into the future. It was only a few years back the melting of the tundra was identified as 'accelerating effect' of climate change, as that thawing permafrost releases its methane into the atmosphere.
hodgesrm 5y ago
> which would also amplify the frequency of these events. At least until the fuel is gone. If we don't overcome forest management practices like fire suppression, the ecosystem will simply turn over to something less vulnerable to fire. To your point it won't be the existing species like Doug Fir, Live Oak, or Jeffrey Pine.
pvaldes 5y ago
> we might lose a lot of forest. Not a lot, all. The ecosystem is changing towards the desert side. Forests need a minimum amount of water to sustain them. Could be replaced by arid forests, made to burn. But the humid forests will disappear or became relict. Is happening in California since several years ago.
throwaway0a5e 5y ago
>which would also amplify the frequency of these events. Fire needs three things. One of them is fuel. The west coast has an abundance of fuel because for generations we have prevented fires from removing it. If we stop doing that or the fires are too overwhelming to manage the fuel will go away and the problem will solve itself. It will just be way more fiery because you're compressing say 100yr worth of fuel consumption into say a decade.

bamboozled 5y ago

Yes, this is what will happen in many areas.

RadioactiveMan 5y ago

Would we really lose them? My understanding is that, after a fire, a forest experiences very rich growth, especially of plants that don't grow much under the shade of old trees, which are good food and cover for many animals.

jszymborski 5y ago
Right, but it takes ages for forests to grow, and that period is plenty time for CO2 emissions to run-away from us.
- tomc1985 5y ago
  There is a small but growing movement towards controlled burns of forests and such because not burning for long enough creates conditions that make wildfires even bigger and harder to stop. If you can rotate between enough zones over time the burned area can regrow fully. It has been said that part of the reason wildfires get so bad now is because we do not let them partake in their normal cycle of burning down occasionally.
  - bawolff 5y ago
    What do you mean small but growing? This is mainstream e.g. https://www2.gov.bc.ca/gov/content/safety/wildfire-status/prevention/vegetation-and-fuel-management/prescribed-burning https://www2.gov.bc.ca/gov/content/safety/wildfire-status/pr...
    - s1artibartfast 5y ago
      It isn't implemented anywhere near the natural level, let alone the required levels to offset 150 years of suppression.
- dredmorbius 5y ago
  I'll lead with: yes, these fires are devastating. Ironically, if topsoil isn't sterilised or washed away, and both can and do happen with the mega fires we've been seeing, fresh growth after a wildfire can be stunningly quick. A mature forest is self-limited by the existing mature growth --- juvenile trees simply cannot get sufficient light. If mature growth is cleared, the juveniles grow quickly. It's still a slow process, and we're talking about ~30--50 years for a redwood to hit 100' or so (coast redwoods can grow to over 380' / 115m, giant sequoia are more massive but not quite so tall --- 286' / 87m. As carbon sinks, redwood, doug fir, ponderosa, and other trees common to the western coastal ranges, Sierra, and Cascades are not insignificant, but probably pale compared to bogs, swamps, wetlands, mangroves, and tropical rainforests. Thats' a general sense, though I don't have solid numbers at hand. Burning down the Sierra, Cascades, and Rockies isn't going to do us any favours. But it's still relatively modest. I'd be more concerned about tundra / permafrost melting and release, bog fires, wetlands loss, and rainforest. Unfortunately we'll likely see all of that as well.
  - jszymborski 5y ago
    Well, I learned a lot today! Thanks for the free education :)
micro_cam 5y ago
These current fires are much more destructive because of a combination of the extreme conditions, a dense under story from fire suppression and lots of standing dead wood from beetle kill etc. So ideally for a forest you would have small fires come through regularly and clean up the under brush but leave a fair number of large mature trees standing leading to open fire resistant mature forest. With these large super destructive fires that wipe out everything you get slower reseeding which can let invasives weeds take hold. And you get dense stands of young trees and brush which are less fire resistant than mature forests. Partial solutions include controlled burns in the wet season and thinning where you shoot to leave the large mature trees but reduce fuels. (This isn't always commercially viable though developing wood products that can be made from small trees or even brush harvested during thinning is an interesting area.)
- Arrath 5y ago
  > With these large super destructive fires that wipe out everything you get slower reseeding which can let invasives weeds take hold. And you get dense stands of young trees and brush which are less fire resistant than mature forests. If you're real unlucky an above average wet season after a super destructive fire will cause untold amounts of topsoil erosion and damage, impacting the follow on reseeding even more.
  - micro_cam 5y ago
    Oh yeah, full on mud slides are quite common after a fire.
- bawolff 5y ago
  Are current fires actually much more destructive? https://cwfis.cfs.nrcan.gc.ca/data/charts/NFD_NFDB_comparison_stats_chart.png https://cwfis.cfs.nrcan.gc.ca/data/charts/NFD_NFDB_compariso... seems to suggest that the average year is getting worse but really big outliers are getting rarer. https://www.google.com/amp/s/globalnews.ca/news/8045796/canada-wildfires-yearly-trends/amp/ https://www.google.com/amp/s/globalnews.ca/news/8045796/cana... suggests we have a higher number than normal but below average in total area burnt.
coliveira 5y ago
Yes, that would be the case in normal conditions. Not if huge swaths of the forest are destroyed annually.
pvaldes 5y ago
> Would we really lose them? Yes, at least without human intervention. The stress concept in ecology predicts more biodiversity at minor events, but much less at large-scale global events. A pinch of disturbance is good for the life beings. This levels of disturbance at the same time in the North and in Brazil are not good.

slownews45 5y ago

There was much much more fire in the past. California is a terrible example if you want to show natural / historic rates of fire. I'm sure native american's burned huge quantities for lots of reasons as well?

beowulfey 5y ago
If you want to make statements like this on HN, please back them up with sources.
- hodgesrm 5y ago
  The paper cited below estimates that 1.8M hectares burned annually in California before 1800 (over 4M acres). [1] That's about how much burned in 2020. [2] [1] https://nature.berkeley.edu/stephenslab/wp-content/uploads/2015/04/Stephens-et-al.-CA-fire-area-FEM-2007.pdf https://nature.berkeley.edu/stephenslab/wp-content/uploads/2... [2] https://en.wikipedia.org/wiki/2020_California_wildfires https://en.wikipedia.org/wiki/2020_California_wildfires Edit: clarity
  - dragonsky67 5y ago
    I'm wondering what type of fires these were. There is a vast difference between a forest crown wild fire, and a cooler one that mostly works burning undergrowth and leaf litter. Still fires, still covering the same amount of ground, one can destroy the forest and anything else in the vicinity, the other can help plants germinate and seeds the forest for the next period of growth.
    - s1artibartfast 5y ago
      They were low intensity fires. Many areas burned every 3 years on average before 1850. These same areas haven't experienced a fire since 1900
    - slownews45 5y ago
      You only get high intensity fires if you have too LITTLE fire, not too much. If you have annual burning it's not going to be high intensity. That said, even high intensity fires have pretty impressive recovery. Do you want to give me a high intensity fire from 5+ years ago? I can then show you the recovery if you want.

BurningFrog 5y ago

Burning forests will increase the CO₂ level, but since there is no "local global warming", the effect is diluted over the whole planet, and I'd be very surprised if the feedback effect is at all significant.

coliveira 5y ago
Except that is not happening only in the NW. From Australia to Siberia to the Amazon forest, you see the same pattern.
cryptoz 5y ago
> since there is no "local global warming" There is, though. Climate change has different impacts depending on where you are. Some areas are rising in temperature much much faster than others. The arctic is a good example of 'local global warming'. > I'd be very surprised if the feedback effect is at all significant Prepare to be surprised. Even if there are 1000 factors each of them only contributing .1% to the total, it is still the case that each one of the 1000 factors is significant.
- Denvercoder9 5y ago
  You're right that some areas are impacted more by climate change, but that's not correlated with the areas that emit more CO2. In other words: local emissions don't determine local warming.
  - cryptoz 5y ago
    I really don't think that's true, or at least, it's not as clear-cut as you are asserting. There is at least healthy debate about the issue and it is definitely not a closed case of "local emissions don't determine local warming". As far as I can tell, local emissions do relate to increased local warming. Here's a source https://www.scientificamerican.com/article/can-carbon-dioxide-domes-affect-health/ https://www.scientificamerican.com/article/can-carbon-dioxid...

ErikVandeWater 5y ago

This made me go back and read about cloud seeding. I'm surprised at how controversial its efficacy is. It seems it would be simple to set up in a lab conditions that would be favorable for a cloud seeding mission in the real world (conditions where the air is moist but not precipitating). Insert the silver iodide and see how much of the water in the air condenses. Multiply it out to see how much silver iodide you would need to substantially increase rain. Test in different conditions to see the operating window for cloud seeding is. It should be noted that the benefit of cloud seeding is not necessarily increasing total rainfall in a region, but controlling where that rainfall occurs.

dxbydt 5y ago
You don't need silver iodide & suchlike. You can build a simple catapult & fire drones into the cloud. The drone delivers an electric charge to the cloud. This dislodges the water which falls down as rain. This is already routine[1] [1] https://www.bbc.com/news/technology-56428984 https://www.bbc.com/news/technology-56428984
- ErikVandeWater 5y ago
  The article says they are in the proof of concept stage.
  - dxbydt 5y ago
    that bbc report is from march. here's a recent update from last week. it actually works very well - lots of rain. https://www.usatoday.com/story/news/world/2021/07/21/cloud-seeding-uae-artificial-rain-drones-electricity/8040330002/ https://www.usatoday.com/story/news/world/2021/07/21/cloud-s... https://www.newsweek.com/dubai-creates-fake-rain-using-drones-battle-122-degree-heat-1611887 https://www.newsweek.com/dubai-creates-fake-rain-using-drone...

jussij 5y ago

Undoubtedly more of these positive feedback loops will identify themselves going into the future. It was only a few years back the melting of the tundra was identified as 'accelerating effect' of climate change, as that thawing permafrost releases its methane into the atmosphere.

hodgesrm 5y ago

> which would also amplify the frequency of these events. At least until the fuel is gone. If we don't overcome forest management practices like fire suppression, the ecosystem will simply turn over to something less vulnerable to fire. To your point it won't be the existing species like Doug Fir, Live Oak, or Jeffrey Pine.

pvaldes 5y ago

> we might lose a lot of forest. Not a lot, all. The ecosystem is changing towards the desert side. Forests need a minimum amount of water to sustain them. Could be replaced by arid forests, made to burn. But the humid forests will disappear or became relict. Is happening in California since several years ago.

throwaway0a5e 5y ago

>which would also amplify the frequency of these events. Fire needs three things. One of them is fuel. The west coast has an abundance of fuel because for generations we have prevented fires from removing it. If we stop doing that or the fires are too overwhelming to manage the fuel will go away and the problem will solve itself. It will just be way more fiery because you're compressing say 100yr worth of fuel consumption into say a decade.