eli5: If plants and trees thrive on Carbon dioxide, and humans are producing more carbon dioxide, does that mean vegetation is benefiting from greenhouse gases? If not, how come?
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The short answer to your question is “yes”. Plants do benefit from elevated CO2 levels. And we’ve got a long way to go before those levels are remotely harmful to humans.
Historic CO2 levels have been far higher than they are now as well as far lower. It is true that humans can increase the rate at which CO2 is released. But it’s not the global killer that it is normally portrayed.
People should be much more worried about toxic pollution than the levels of CO2 and relatively mild changes in weather that happen over many years.
Like saying “don’t humans thrive on water? Why don’t they thrive in the ocean”
You’re correct that plants and trees need carbon dioxide (CO2) to live. They take in CO2 and water, and with the help of sunlight, they turn them into oxygen and sugar in a process called photosynthesis. This is how they grow and reproduce.
So, you might think that if we have more CO2 in the atmosphere because of human activities, plants and trees would be super happy, right? But it’s not that simple. Here’s why:
Too much of a good thing: While plants need CO2 to grow, too much of it can be harmful. Some plants might initially grow more with higher CO2 levels, but this can change over time. For example, studies have found that many plants growing in high CO2 conditions can end up with less nutritious content, like lower protein levels.
Climate change: The extra CO2 that humans are adding to the atmosphere is causing our planet to heat up, a process known as global warming. This leads to changes in weather patterns, melting ice, rising sea levels, and other problems. Plants and trees often have a hard time adapting to these rapid changes. For example, some trees might not be able to survive in areas that become too hot or too dry.
Other nutrients: Plants need more than just CO2 to grow. They also need nutrients from the soil, like nitrogen and phosphorus. If a plant gets lots of CO2 but not enough of these other nutrients, it won’t be able to grow properly.
Pollution: Unfortunately, human activities don’t just produce CO2. They also produce other pollutants that can harm plants, like ground-level ozone. Ozone can damage plants’ leaves and make it harder for them to photosynthesize.
In short, while plants do need CO2 to grow, the overall effect of human-produced greenhouse gases is harmful to them and the planet as a whole because of the complex ways these gases alter our climate and ecosystems.
Yes, it increases the plants growth, but it *also changes the weather patterns. A plant may be enjoying more growth, but be killed by unseasonably hot weather too. Carbon level is only one factor.
I guess we can’t just feed plants junk food and expect them to thrive like we do with carbon dioxide.
It would. It’s just that CO2 also means that the place is becoming a proverbial hotbox. Trees can’t flourish if they’re on fire
Nobody had directly and correctly answered your question. Ignoring climate, water, and other effects, plants benefit from CO2 increases up to a point. Past a certain point (around twice current carbon dioxide levels for most types of vegetation) a process called respiration overtakes photosynthesis, and plants stop being able to grow as well, and start breathing out more carbon than they take in. Eventually, it becomes too much of a good thing.
I am sure you have seen that we have a new environmental issue, algae growth.
There many lakes and more or less stagnant part of rivers that algae starts to force out some flora and fauna.
On the other hand, elevated CO2 causes elevated temperatures, which is bad for plants too. So more “food” but less habitability for plants. Back to algae, they are not as sensitive to temperature changes.
Just from an evolutionairy stand point, plants will, to a certain degree, have developed in such a way, that the CO2 levels of the atmosphere they are growing in are optimal for their growth. I would also assume that CO2 is the least scarce nutrient, while other nutrients, such as nitrogen, minerals and water or even light, are the ones that limit the growth of the plant.
Kinda sorta. Yes, we can actually measure that trees produce more biomass in summer, for instance, iirc. That is due to the additional availability of CO2. Kind of the same for some algae blooms. However, the higher evaporation, lower surface availability of water and just the rising temperatures themselves in summer more than offset the benefits. To put it short. Wet places are getting somewhat more lush, but more places become arid.
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