Scientists point a finger at greenhouse gasses, such as carbon dioxide, when it comes to global warming, which has negative repercussions for humans. However, some people have wondered if an increase in carbon dioxide could also be beneficial to some life forms on our planet. Could this increase in carbon be good for plants, which convert carbon dioxide to sugar and oxygen in a process known as photosynthesis?
With more carbon dioxide in the air, some plants may grow faster. However, this isn’t always a positive. Imagine a world where all the plants grow twice as fast. You’d have to mow your lawn and trim the hedges twice as often to keep them looking presentable. The same goes for plants and trees that might pose safety hazards in the wild. Some of these activities might, in turn, produce even more carbon dioxide.
Not all plants grow faster with more carbon dioxide in the air, either. Generally, it’s only the crops and younger plants that will do so, while mature forests won’t see the same growth increase. Even if all plants could grow more rapidly in response to the carbon dioxide in the air, this growth wouldn’t require twice as much CO2.
When a plant dies or is harvested, the carbon that it was storing is subsequently transferred to the soil. The soil can only hold so much carbon and will reach its carbon saturation point after between 50 to 100 years. Additionally, the soil only holds carbon as long as it remains undisturbed. With efforts to manage wetland, reforest the land, and farming, all of which are examples of terrestrial sequestration practices, the soil can remain undisturbed for longer. Compared to what plants can do, terrestrial sequestration may be more effective at removing carbon from the atmosphere.
Another factor to consider is whether they can and how plants may contribute toward moisture in dry areas. Plants have pores known as stomata, which release water. With higher carbon levels in the atmosphere, these pores close, and plants lose less water. Hypothetically, an area that’s not too warm could see a benefit from this, but we’re unlikely to see much water saving in places that are hot enough for water to evaporate, essentially negating the impact of this function.