6 ms·

> plants love CO2 In artifical conditions in laboratory there is a significant effect, up to 20% when doubling pre-industrial CO2 concentration. But, in pract

by ajuc 8y ago

> plants love CO2 In artifical conditions in laboratory there is a significant effect, up to 20% when doubling pre-industrial CO2 concentration. But, in practice for wild plants nitrogen quickly becomes the bottleneck, so the real gains are much smaller. And even for farming plants (which have fertilizer providing additional nitrogen) the real gains diminish, and are more in 5-10% range. For some crops CO2 has very little effect at all (for example corn). Additionally - crops grew with raised CO2 levels have less proteins and useful nutrients. And then you have to factor in the harmful effects from global warming on crops (heat damage, dry soil, less farmland available) and the overall effect is likely negative. https://www.scientificamerican.com/article/ask-the-experts-does-rising-co2-benefit-plants1/ https://www.scientificamerican.com/article/ask-the-experts-d...

manmal 8y ago
In the movie Interstellar, mildew was the straw that broke the camel‘s back for agriculture. From what I‘ve read, this can be a possibility if CO2 rises too high.
- bewo001 8y ago
  And it was somehow easier to move people and farms to a giant space station than to build climate controlled greenhouses on earth. But it looked stunning in the movie..
  - tjpaudio 8y ago
    The space station was an arc traveling to the new planet they found.
  - manmal 8y ago
    People also got sick and died from dust particles, I guess the conjecture was that earth would soon become uninhabitable.
ph0rque 8y ago
Here's where a management that aims for diversity of plants comes in handy. If care is taken to plant the correct proportion of nitrogen-fixing plants, and other plants (such as comfrey) that will grow really deep roots to extract trace minerals, the nutrient density can be increased. There are techniques to increase the soil fertility with the correct selection of plants. There is a design science, permaculture, that takes all these factors into account.
- graeme 8y ago
  That applies to farming, but not to nature. All current animals evolved with the amount of nutrients in plants on average now. If that changes quickly, they'll have a hard time adapting.
whatshisface 8y ago
If the bottleneck changes from CO2 to Nitrogen, maybe plants will start adapting to get better at fixation, pushing that limit higher than the CO2 limit.
- EvilGrin 8y ago
  This sounds like something the GMO industry would be working on already.
- azernik 8y ago
  That kind of evolution takes a while.
- logfromblammo 8y ago
  Plants don't really get better at fixing nitrogen. They get better at hosting symbiotic colonies of nitrogen-fixing microbes in their root systems. It's splitting a hair, to be sure, but developing root nodules for hosting a nitrogen-fixer species is a lot easier than evolving all the biochemical precursors from scratch. Nitrogen fixation symbiosis may have evolved independently in plants at least three times. It would have been a big advantage from 460 to 380 Mya and then again, to a far lesser extent, from 240 to 160 Mya. Teredo shipworms also employ nitrogen-fixing symbionts, in their gill structures, as well as some termites, in their guts, but the latter only derive benefit in an extremely low-nitrogen environment. Since atmospheric CO2 has dropped after the last peaks, some plant species failed to preserve that symbiosis. They would have an easier time getting it back, now that CO2 partial pressure is rising back to levels experienced in prior geological eras. The ultimate bottleneck is likely to be iron or magnesium.
mrfusion 8y ago
I believe in global warming with all my heart but just to be balanced the heat also gives you a longer growing season and let’s plants thrive in higher latitudes. Edit funny the downvotes. I’m on your team guys! Just think we can’t ignore counter facts.
- grigjd3 8y ago
  The length of the growing season is affected by many things, like rain, days below freezing, days above threshold temperatures, etc. It's not clear at all that warmer global temperatures means a longer growing season.
- NeedMoreTea 8y ago
  For crops that tolerate the extra heat. Those which don't will need to be grown further toward the poles, which will reduce the length of growing season.
  - theli0nheart 8y ago
    Plants adapt. The ones that can tolerate the extra heat will survive better and therefore propagate more than plants that don't.
  - BurningFrog 8y ago
    Reseeding a field with a new crop is technology known since thousands of years. I don't think there is any risk of areas reaching temperatures too hot for any plants? > which will reduce the length of growing season Why?
    - GlenTheMachine 8y ago
      ...because plants that are overheated can't grow. Depending on how overheated they get they may merely become stressed, or they can die. But plants also need temperatures, particularly soil temperatures, that rise above some minimum before they germinate. So you need a period when the soil temperature is high enough, but the air temp is not too high. Figuring out the length of that window is very complicated. Corn, for instance, can't grow when the temp is over 104 or so (depending on cultivar) and dies when exposed to temps over 110 or so. It maximizes its growth rate at around 86 degrees. So: if you have a summer month when temps are regularly over 104, that's not really a growing season for corn. Thus you have to try to plant earlier and harvest earlier, and the window when you can do that successfully may be considerable shorter than it would if the temp stayed below 104 during the summer. So then you try to go closer to the poles. But -- depending on temperatures and a lot of other factors -- that may not be a totally satisfying solution either. Corn needs specific amounts of rain, which may or may not coincide with periods when the temperatures are good. It also needs large amounts of soil nitrogen, which may or may not be present in arctic soils, and if the plant doesn't have it growth is slowed. Corn also needs the soil temperature to be relatively high to germinate (above 50 degrees, again depending somewhat on cultivar). In arctic soils, it may take a while for the soil to warm up that much in the spring, and that may reduce your growing season. So how all the factors play out, and whether those factors result in a longer or shorter growing season, are intimately connected to exactly how the climate changes. I've used corn as an example, but of course other crops and wild plants all rely on complicated, interconnected conditions to thrive. The specifics are a bit different for every plant. It all depends. There are a lot of factors that we won't really know until people start trying to do it.
kingkawn 8y ago
If you seeded an ecosystem with nitrogen supplements would it allow the plant life to grow at an accelerated rate and capture carbon?
- gepoch 8y ago
  You use ammonia to add nitrogen to crops. Making ammonia is an extremely energy intensive process that already contributes about 2-3% of global carbon emmissions. [1] So you could spray ammonia everywhere to promote growth, but it's not clear that you'll offset the carbon emissions from making so much ammonia in the first place. [1] https://m.phys.org/news/2018-07-electrochemically-produced-ammonia-revolutionize-food-production.html https://m.phys.org/news/2018-07-electrochemically-produced-a...
  - kingkawn 8y ago
    Ahh that’s what I figured, too bad nitrogen fixing cover crops is the way in agriculture I guess
- gameswithgo 8y ago
  we are already doing that aggressively to feed everyone, and we worry it might be hard to keep it up, as is.

by ajuc 8y ago

manmal 8y ago

In the movie Interstellar, mildew was the straw that broke the camel‘s back for agriculture. From what I‘ve read, this can be a possibility if CO2 rises too high.

bewo001 8y ago
And it was somehow easier to move people and farms to a giant space station than to build climate controlled greenhouses on earth. But it looked stunning in the movie..
- tjpaudio 8y ago
  The space station was an arc traveling to the new planet they found.
- manmal 8y ago
  People also got sick and died from dust particles, I guess the conjecture was that earth would soon become uninhabitable.

ph0rque 8y ago

Here's where a management that aims for diversity of plants comes in handy. If care is taken to plant the correct proportion of nitrogen-fixing plants, and other plants (such as comfrey) that will grow really deep roots to extract trace minerals, the nutrient density can be increased. There are techniques to increase the soil fertility with the correct selection of plants. There is a design science, permaculture, that takes all these factors into account.

graeme 8y ago
That applies to farming, but not to nature. All current animals evolved with the amount of nutrients in plants on average now. If that changes quickly, they'll have a hard time adapting.

whatshisface 8y ago

If the bottleneck changes from CO2 to Nitrogen, maybe plants will start adapting to get better at fixation, pushing that limit higher than the CO2 limit.

EvilGrin 8y ago
This sounds like something the GMO industry would be working on already.
azernik 8y ago
That kind of evolution takes a while.
logfromblammo 8y ago
Plants don't really get better at fixing nitrogen. They get better at hosting symbiotic colonies of nitrogen-fixing microbes in their root systems. It's splitting a hair, to be sure, but developing root nodules for hosting a nitrogen-fixer species is a lot easier than evolving all the biochemical precursors from scratch. Nitrogen fixation symbiosis may have evolved independently in plants at least three times. It would have been a big advantage from 460 to 380 Mya and then again, to a far lesser extent, from 240 to 160 Mya. Teredo shipworms also employ nitrogen-fixing symbionts, in their gill structures, as well as some termites, in their guts, but the latter only derive benefit in an extremely low-nitrogen environment. Since atmospheric CO2 has dropped after the last peaks, some plant species failed to preserve that symbiosis. They would have an easier time getting it back, now that CO2 partial pressure is rising back to levels experienced in prior geological eras. The ultimate bottleneck is likely to be iron or magnesium.

mrfusion 8y ago

I believe in global warming with all my heart but just to be balanced the heat also gives you a longer growing season and let’s plants thrive in higher latitudes. Edit funny the downvotes. I’m on your team guys! Just think we can’t ignore counter facts.

grigjd3 8y ago
The length of the growing season is affected by many things, like rain, days below freezing, days above threshold temperatures, etc. It's not clear at all that warmer global temperatures means a longer growing season.
NeedMoreTea 8y ago
For crops that tolerate the extra heat. Those which don't will need to be grown further toward the poles, which will reduce the length of growing season.
- theli0nheart 8y ago
  Plants adapt. The ones that can tolerate the extra heat will survive better and therefore propagate more than plants that don't.
- BurningFrog 8y ago
  Reseeding a field with a new crop is technology known since thousands of years. I don't think there is any risk of areas reaching temperatures too hot for any plants? > which will reduce the length of growing season Why?
  - GlenTheMachine 8y ago
    ...because plants that are overheated can't grow. Depending on how overheated they get they may merely become stressed, or they can die. But plants also need temperatures, particularly soil temperatures, that rise above some minimum before they germinate. So you need a period when the soil temperature is high enough, but the air temp is not too high. Figuring out the length of that window is very complicated. Corn, for instance, can't grow when the temp is over 104 or so (depending on cultivar) and dies when exposed to temps over 110 or so. It maximizes its growth rate at around 86 degrees. So: if you have a summer month when temps are regularly over 104, that's not really a growing season for corn. Thus you have to try to plant earlier and harvest earlier, and the window when you can do that successfully may be considerable shorter than it would if the temp stayed below 104 during the summer. So then you try to go closer to the poles. But -- depending on temperatures and a lot of other factors -- that may not be a totally satisfying solution either. Corn needs specific amounts of rain, which may or may not coincide with periods when the temperatures are good. It also needs large amounts of soil nitrogen, which may or may not be present in arctic soils, and if the plant doesn't have it growth is slowed. Corn also needs the soil temperature to be relatively high to germinate (above 50 degrees, again depending somewhat on cultivar). In arctic soils, it may take a while for the soil to warm up that much in the spring, and that may reduce your growing season. So how all the factors play out, and whether those factors result in a longer or shorter growing season, are intimately connected to exactly how the climate changes. I've used corn as an example, but of course other crops and wild plants all rely on complicated, interconnected conditions to thrive. The specifics are a bit different for every plant. It all depends. There are a lot of factors that we won't really know until people start trying to do it.

kingkawn 8y ago

If you seeded an ecosystem with nitrogen supplements would it allow the plant life to grow at an accelerated rate and capture carbon?

gepoch 8y ago
You use ammonia to add nitrogen to crops. Making ammonia is an extremely energy intensive process that already contributes about 2-3% of global carbon emmissions. [1] So you could spray ammonia everywhere to promote growth, but it's not clear that you'll offset the carbon emissions from making so much ammonia in the first place. [1] https://m.phys.org/news/2018-07-electrochemically-produced-ammonia-revolutionize-food-production.html https://m.phys.org/news/2018-07-electrochemically-produced-a...
- kingkawn 8y ago
  Ahh that’s what I figured, too bad nitrogen fixing cover crops is the way in agriculture I guess
gameswithgo 8y ago
we are already doing that aggressively to feed everyone, and we worry it might be hard to keep it up, as is.