The levels of CO2 in the atmosphere is increasing and have done so for many years. Shouldn’t this have a positive impact on plants etc.?
Maybe not nature including humans, but plants should thrive, right?
In: 2
One, there is more CO2 then the plants can eat. We are making it too fast.
Two, we murdered all the plants.
Algae, many molds and many plants will love it.
You and the rest of humanity? You’re gonna have a bad time.
The CO2 itself is very positive for nature in many cases, but the additional heat that the CO2 causes is very bad for nature.
Particularly bad for the apart of nature that is US.
“CO2 Fertilization” has been researched and it does boost plant productivity briefly, but then the plants adjust and go back to normal. Usually they end up limited by other nutrients/environmental factors that make it so increased CO2 doesn’t help them long-term. Climate change has other bad effects like bigger temperature swings, droughts, wildfires, etc. So overall the harms vastly outweigh a temporary boost to plant growth.
In the way that I see it, your reasoning is right, but you gotta consider that for each new source of CO2 created tons of trees and plants are also mowed down so in the end you just have a lot more CO2 than plants to process it.
It is beneficial for nature. Rainforests are expanding. More green areas on Earth now than 40 years ago.
Many reasons
1. Nature is pretty delicate, changing any one variable on a global scale by a small percent will have ripple effects all over the place.
2. CO2 creates the greenhouse effect, i.e. heats up the planet
3. Clarification, when people talk about “X Tons of CO2”, they almost *always* mean “Equivalent to X Tons of CO2”. There are dozens of common carbon-based emissions, many which are far worse than an actual CO2 of similar mass. There are estimates about how much worse each is, and then they do a conversion. So if methane is 10X worse than CO2, and a ton of methane is released, you’ll here “10 tons of carbon emissions”
Plants breathe CO2 so that’s good for them. The major downside from plants’ perspective is that extra CO2 traps more heat from the sun, making the world hotter and drier. And that results in more and larger fires. Those aren’t particularly great for nature.
As others have said, there’s also a lot of complexity in the way different elements of the ecosystem interact, so it’s hard to predict many specific individual outcomes.
Just like how humans can have too much CO2, so can plants. Combine in other effects, like increased temperature, higher or lower humidity, nutrient uptake changes, and things get bad for contemporary plants with an increased CO2 level, combined with other increases. Remember, all the plants that are around, developed in a relatively stable environment with low CO2.
One of the big issues is that since the CO2 increases temperatures, we see more stomatal closures on plant leaves, and we see a decrease in evapotranspiration (releasing of water vapour). This latter part might sound like a good thing, the plants lose less water, well when plants lose water, that water turns into rain. So we see less rain falling in rainforests, because there is simply less water in the water cycle.
Increased CO2 levels also increase the thickness of the leaves. Plants with thicker leaves are worse at capturing CO2, amongst getting worse at other things.
Increased temperature also increasing the rate at which the plants respire, so they hold on to less of the CO2 than had the temperatures been lower.
If you can increase CO2 without increasing those other things, like temperature. It works out great, which is why it works in green houses. But it doesn’t represent reality.
Like others have said, it’s an incredibly complex issue that we haven’t had to deal with, so we are learning new things all the time. I only learned about the leaf thickness thing last year, and the science behind it only goes back to 2018 because that’s when we started noticing that in certain places, the leaves were getting thicker (by as much as 1/3rd), tests showed it was a reaction to increased CO2 levels and all that it brings with it.
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