New research indicates that ironically, as we stabilize carbon dioxide in the atmosphere and begin to reduce it, the carbon land sink—the CO2 stored in soil and plants—will decline. This comes from research by scientists in Germany and the United Kingdom, who have found that doubling carbon dioxide concentrations will result in about a one-third increase in plant photosynthesis.
Basically, as carbon dioxide in the atmosphere increases, plants will take in more of it, though they will never quite catch up.
It is widely accepted that plant photosynthesis will increase with carbon dioxide, so long as nutrients, such as nitrogen and phosphorous, are not limiting, say the researchers.
Plants use carbon dioxide to perform photosynthesis, after which they release oxygen into the atmosphere. Plants are in turn eaten by animals, and so forth. It’s a process we’re all very familiar with, but the math of it all is something that we’re learning more about all the time.
The more we know about how CO2 is stored naturally, the more we can learn about how to store it through artificial means, which could produce tools that allow us to decrease the amount of CO2 in the atmosphere.
Study co-author Professor Peter Cox of the University of Exeter, says “despite nutrient limitations in some regions, our study indicates that CO2-fertilization of photosynthesis is currently playing a major role in the global land carbon sink. This means we should expect the land carbon sink to decline significantly when we begin to stabilize CO2.”
Soil, trees, and oceans store a lot of CO2, but these systems aren’t perfect. Plants don’t photosynthesize in the winter, soil is far more effective if it’s part of old growth forest, and the oceans have reached a storage peak: More carbon there means more acidic water, which has many negative side effects.
Ultimately, stabilizing the carbon sink will be the best choice for all life on the planet. Until then, though, we can give credit to plants for their help in balancing out the carbon dioxide emissions produced by humankind.