Though plants consume carbon dioxide from the atmosphere and prepare their food, forests are thought to be the most important carbon sinks. As we know that human activities produce most carbon, scientists have always debated on this point that if plants are photosynthesizing more to consume more carbon than they actually need.
A team of researchers from Lawrence Berkeley National Laboratory have created a method by combining remote sensing and machine learning to find out that plants are really photosynthesizing more. They found out between the years 1982 to 2020 the global carbon dioxide concentrations increased by 17% and with it the plants have photosynthesized 12 times more than they usually do.
The plants have taken up 14% of the emitted carbon and this percentage only equivalents the total amount of carbon emitted from burning fossil fuels in 2020 alone.
But the carbon that plants consumed by photosynthesis has also returned in the atmosphere by the plants through respiration. The new study found out a direct link between increased photosynthesis and increased global carbon.
This research paper has been published in Nature.
Carbon stays in the atmosphere much longer than other greenhouse gases and the reduction of carbon is important to mitigate climate change. Photosynthesis emits a third of carbon that is emitted by the burning of fossil fuels each year.
When plants photosynthesis, they open tiny pores on their leaf to suck carbon from the air. Scientists can measure how much carbon the leaf is sucking by placing it under a closed chamber. But it is not possible to measure how much carbon an entire forest is sucking up.
But now, scientists have built 500 micrometeorological towers in forests to measure the exchange of carbon between atmosphere and plants. Though these towers can estimate photosynthesis rates, but they are expensive and have limitations in their geographic coverage.