3 ms·

I’d be curious how they explain the fact that greenhouses typically add co2 for faster growth? ( disclaimer I believe in global warming with all my heart)

DennisP 8y ago
Greenhouses are controlled environments where everything else is abundant too. In more natural environments, plants are limited by availability of water and nutrients in the soil. On top of that, plant growth can be reduced by heat stress. They also have to contend with insects and disease, and may not have good defenses when climate change has brought invasive organisms to the area.
- dragonwriter 8y ago
  Sure, but what that suggests is that the existing established understanding is correct (or at least still plausible): even if the particular trees studied here aren't CO2-limited and don't grow more with more CO2, total plant biomass will or at least might (outside of climate change denial fantasies this doesn't mean increases in CO2 will automatically be neutralized by plant growth, because it doesn't imply that the size of the effect is necessarily sufficient to clear the additional CO2 once long-term equilibrium is reached, doesn't tell you how long it takes plants to reach the new equilibrium when CO2 levels have reached a new plateau, and even if it did all that wouldn't help when CO2 levels are constantly increasing and plant growth can't catch up.)
  - DennisP 8y ago
    Sure, if everything else is ideal then many plants will grow more with more CO2. Even this study's authors don't deny that; they say that other factors will often not be ideal: "climate change is generating warmer, drier conditions that could make them grow less in many places" Overall, conditions are definitely getting warmer on average, and many places are also getting drier, sometimes with occasional very heavy rainfalls that wash away topsoil. Another factor I didn't mention is forest fires, brought about by drier conditions, as we've been seeing in California.
    - dragonwriter 8y ago
      I'm not taking issue with the study or it's authors, just the presentation of the article, which very heavily spins it, especially up front, as contradicting the existing understanding broadly, when it really doesn't. It's important, because the fertilizer for anti-science attitudes exploited by groups like climate denialists is a false impression of radical flip-flops in science conveyed by popular media which uses exaggerated contradiction to overplay the impact of stories and draw eyeballs.
sampleinajar 8y ago
Based no my limited knowledge in this field, I believe that is because it is an enclosed and controlled system. You can increase all variables (CO2, water, nutrients) together; whereas, a plant in "the wild" cannot. Most things act more conservatively in Nature versus human controlled environments.

DennisP 8y ago

Greenhouses are controlled environments where everything else is abundant too. In more natural environments, plants are limited by availability of water and nutrients in the soil. On top of that, plant growth can be reduced by heat stress. They also have to contend with insects and disease, and may not have good defenses when climate change has brought invasive organisms to the area.

dragonwriter 8y ago
Sure, but what that suggests is that the existing established understanding is correct (or at least still plausible): even if the particular trees studied here aren't CO2-limited and don't grow more with more CO2, total plant biomass will or at least might (outside of climate change denial fantasies this doesn't mean increases in CO2 will automatically be neutralized by plant growth, because it doesn't imply that the size of the effect is necessarily sufficient to clear the additional CO2 once long-term equilibrium is reached, doesn't tell you how long it takes plants to reach the new equilibrium when CO2 levels have reached a new plateau, and even if it did all that wouldn't help when CO2 levels are constantly increasing and plant growth can't catch up.)
- DennisP 8y ago
  Sure, if everything else is ideal then many plants will grow more with more CO2. Even this study's authors don't deny that; they say that other factors will often not be ideal: "climate change is generating warmer, drier conditions that could make them grow less in many places" Overall, conditions are definitely getting warmer on average, and many places are also getting drier, sometimes with occasional very heavy rainfalls that wash away topsoil. Another factor I didn't mention is forest fires, brought about by drier conditions, as we've been seeing in California.
  - dragonwriter 8y ago
    I'm not taking issue with the study or it's authors, just the presentation of the article, which very heavily spins it, especially up front, as contradicting the existing understanding broadly, when it really doesn't. It's important, because the fertilizer for anti-science attitudes exploited by groups like climate denialists is a false impression of radical flip-flops in science conveyed by popular media which uses exaggerated contradiction to overplay the impact of stories and draw eyeballs.

sampleinajar 8y ago

Based no my limited knowledge in this field, I believe that is because it is an enclosed and controlled system. You can increase all variables (CO2, water, nutrients) together; whereas, a plant in "the wild" cannot. Most things act more conservatively in Nature versus human controlled environments.