A recent study revealed that the role of plants in nature-based carbon removal projects has limited potential for mitigating climate change. A team of international researchers led by Dr Heather Graven, Reader in Climate Physics at Imperial College London, has found out that the global carbon taken up and stored by plants is only for short terms. In contrast to what was previously thought, carbon emissions absorbed by plants are released back into the Earth’s atmosphere at a faster rate than what has been previously predicted.
According to the new study, the findings imply that the role of nature in mitigating climate change by way of nature-based carbon removal initiatives like massive tree-planting, potentially has limited effect. The findings revealed that living plants do not store carbon for long term as previously surmised. Plants release the carbon back to the air after using it to produce new tissues.
Understanding the Effect of the Net Primary Productivity Rate of Plants
Through a measurement known as Net Primary Productivity Rate, it is determined how quick plants release stored carbon into the air. Up to now, the measure has been estimated by scaling up data taken from individual sites, However, the scantiness of sites that can provide comprehensive measurements makes it impossible to calculate the Net Primary Productivity rate with utmost accuracy.
Dr. Graven says that the productivity rate of plants has been increasing since the 1900s, of which only 30% of CO2 emissions from human activities have been stored by plants. Subsequently the plants released back the carbon into the air after tissue production processes. Based on those findings, the international researchers concluded that existing climate models have been overestimating how long carbon stays stored in vegetation on a global scale.
Dr. Graven remarked that while governments and corporations rely on plants in drawing down the CO2 warming the planet, it should be understood that the stored carbon will not be locked-in for long in the ecosystem. Globally, plants are currently more productive, which means carbon is released back into the air sooner than expected.
