Nowadays climate change and global warming has come into people’s sight. Global warming is the increase in surface temperature due to greenhouse gases release. This is very negative to all life on Earth and it will impact our future. Plants take up a very important role in the environment. One of their main functions is taking in carbon dioxide. Plants can take in 30% of carbon dioxide emitted by humans each year. With the rising carbon dioxide, plants can increase their rate of photosynthesis, therefore making the plants grow faster. It seems like a positive thing for plants, however, there are many side effects to it. There are much more negative effects on plants such as limited nitrogen take ins and the rising temperature all make plants harder to survive.
When there is an increased level of carbon dioxide in the environment, plants will take in more carbon dioxide by having an increased rate of photosynthesis. This is called carbon fertilization. Because of global warming, researches have found that there is a direct correlation between rate of photosynthesis and the volume of carbon dioxide in the atmosphere. Recently, above-ground plants’ growth rate increased about 21 percent, and the below-ground plants’ growth rate increased about 28 percent. Due to this data, some of the crops will receive a benefit from increasing carbon dioxide by increasing yields from 12 to 14 percent. Because of increased carbon dioxide levels, plants use less water to undergo photosynthesis. This is due to their stomata which allows carbon dioxide to absorb inside while releasing moisture into the atmosphere. Their stomata will partially close which decreases water loss by 5 to 20 percent. This process can make water stay on land rather in the atmosphere.
Even though it seems like a good thing for plants since they can use less water to grow, their nutrients level will be insufficient due to absorbing limited nitrogen. Nitrogen plays a very important role on Earth for plants. They make up 80 percent of the atmosphere and they are essential for plants to create carbohydrates and proteins. Someone may be questioning that there are plenty of nitrogen in the atmosphere, why can’t plants absorb nitrogen from air? Plants cannot take nitrogen in the atmosphere because of its chemical bonding. Nitrogen in atmosphere is composed of two atoms triply bonded. They are very tightly bonded so plants are hard to break it and use it. Most plants have a fixed ratio of carbon and nitrogen in them. Rising carbon dioxide can make plants focus on creating carbohydrates, while diluting some nitrogen on the leaves which slows their productivity. Carbon dioxide may speed up photosynthesis and boost plants productivity, however, without nitrogen the plant can have a shorter lifespan. We usually depend on trees in order to take in the extra carbon dioxide and convert them to oxygen. Again, trees’ sustainable productivity depends on how much nitrogen they can have access to.
Furthermore, higher temperature can make an enzyme involved with carbon fixation less efficient and result in a decrease in plants’ rate of photosynthesis. The ideal temperature for rubisco to function is around 25 degrees celsius. An overall rise of temperature can cause rubisco to change shape and sometimes deactivate. Besides this, warmer temperatures can cause plants to have more time to grow, therefore using more water which offsets the benefit of the partially opened stomata. Soil will eventually become dry as plants take in more water, so plants will become stressed and absorb less carbon dioxide. Warmer winters also help pests and invasive species to survive and cause more harm to plants.
On the surface, plants receive a benefit from global warming, but beneath it can only generate more harm to them. It is important that we raise awareness on global warming and learn more about the negative impacts that are happening to plants right now.
References:
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De Graaff, M., Van Groenigen, K., Six, J., Hungate, B., & Van Kessel, C. (2006). Interactions between plant growth and soil nutrient cycling under elevated CO2: a meta‐analysis. Global Change Biology, 12(11), 2077–2091. https://doi.org/10.1111/j.1365-2486.2006.01240.x
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SciTechDaily. (2024, May 1). New research shows plants are photosynthesizing more in response to more CO2 in the atmosphere. SciTechDaily. https://scitechdaily.com/new-research-shows-plants-are-photosynthesizing-more-in-response-to-more-co2-in-the-atmosphere/
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