Plants are becoming less efficient at CO2 absorption
The carbon dioxide concentration in the atmosphere is increasing, and plants and land ecosystems play an extremely important role in reducing the climate change caused due to this increase in CO2. Carbon dioxide is an ingredient for plants in the process of photosynthesis, which is vital to plant growth.
Trapped CO2 in the atmosphere leads to rise in temperatures (global warming). The main reason why plants help in climate change mitigation is the fact that as they absorb more CO2 for their growth, lesser remains trapped in the atmosphere of the Earth.
However, scientists have discovered that as the concentration of CO2 increases, the efficiency at absorbing it for 86% of land ecosystems around the world is decreasing. As CO2 levels increase, photosynthesis increases as well. This increased rate of plant growth as a result of an increase in CO2 levels is called CFE (CO2 Fertilization Effect).
The opposite of this effect is occurring according to studies, as the global CFE has decreased from 21% to 12% per 10 ppm (parts per million) CO2 since 1982.
Scientists have taken into account other factors necessary to photosynthesis in order to investigate this decrease in CFE, such as water, and sunlight. These other factors may begin limiting photosynthesis and thus may further decrease the mitigation of carbon dioxide in the atmosphere by plants.
According to our data, what appears to be happening is that there’s both a moisture limitation as well as a nutrient limitation coming into play,” Poulter said. “In the tropics, there’s often just not enough nitrogen or phosphorus, to sustain photosynthesis, and in the high-latitude temperate and boreal regions, soil moisture is now more limiting than air temperature because of recent warming.
The effects of global climate change are impacting necessary factors in plant growth, which in turn affect the absorption of CO2 in the atmosphere by plants.