A holistic view is necessary where all intact natural ecosystems are secured and degraded ecosystems are functionally restored
Labelled as the bad-boy of gases, carbon dioxide is a much-misunderstood gas. In reality, it is one of the major reasons for life on Earth; but there has been over 45 per cent increase in carbon dioxide levels in the atmosphere since the beginning of the industrial era, with current average at 412.5 parts per million (ppm).
This has led to human-induced climate change — the biggest global challenge that humans have ever faced. Reducing the emissions is no longer going to suffice; we will have to also ensure that the carbon sinks are maintained and strengthened for human wellbeing.
Carbon dioxide along with other gases such as water vapour, methane, nitrous oxide, and hydroflorocarbons are grouped as greenhouse gases. These gases keep temperatures suitable for life on earth by trapping some of the Sun’s heat. Without them, earth’s surface temperatures would have been like that of the moon.
Then, why is carbon dioxide considered a problem gas? Earth’s systems are in an equilibrium as biotic and abiotic components here interact with each other, creating various cycles such as the carbon cycle, the nitrogen cycle and the water cycle.
These cycles allow life to flourish by utilising the essential ecosystem services emanating from it. Human activities, especially after the industrial revolution, have pumped a lot of carbon dioxide into the atmosphere, increasing the levels by over 100 ppm. This is leading to rising temperatures which disturbs the aforementioned cycles.
All these disturbances have led to climate change and associated challenges. In nature, carbon moves through one storage reservoirs to another, for example in the food chain, where plants convert carbon dioxide from atmosphere into food, which ultimately ends up in soil.
Oceans are critical for carbon storage — they hold 50 times more carbon than the atmosphere. Carbon is also stored in fossils, forests, grasslands, and wetlands, and these stores are called carbon sinks and are equally critical as they help maintain levels of carbon. Without them, life as we know or want will not exist.
Different ecosystems store carbon in different quantities. The world’s forests absorb around 15.6 gigatonnes of carbon dioxide per year; however, 8.1 gigatonnes leak back into the atmosphere due to deforestation, fires and other disturbances.
Role of soil in carbon sequestration is largely overlooked — soil has almost twice the carbon than atmosphere, vegetation, and animals put together, especially in the wetlands that store 643 tonnes per hectare.
While, floating phytoplankton in our oceans absorb up to 20 billion tonnes of carbon dioxide every year, making ocean the largest sequesters of anthropogenic carbon dioxide.
Carbon being fundamental to life, these carbon sinks perform a critical role for economy.
A study estimated the economic value of carbon sequestration in the Mediterranean Sea. According to it, “the contribution of biological processes to the marine “blue carbon” sequestration is always positive, and found to range between 100 to 1,500 million Pounds Sterling every year for the whole basin.”
Other than financial benefits, carbon sinks are crucial for human wellbeing, as healthy natural ecosystems provide food, weather regulation, flood control, and health benefits.
TERI in 2020 estimated that carbon sequestered from forests and Trees Outside Forest (TOF) locked 925.38 million tonnes of carbon dioxide.
However, India’s carbon emissions from just seven sectors resulted in release of 1,113.03 million tonnes of carbon dioxide. Another study in Sariska Tiger Reserve in Rajasthan computed that 1.351 teragrams of carbon was lost between 2000 to 2018 to deforestation resulting in loss of $214.57 million.
Forests and afforestation drives
It is evident that the role of natural ecosystems in sequestering carbon dioxide is central in our fight to keep global temperatures below 1.5 degrees and reduce impacts of climate change.
The Centre has committed that India will restore an additional five million hectares (mha) of degraded land by 2030, raising the total land to be restored in India to 26 mha (COP14 UNCCD).
Also, in 2021, Ministry for Environment, Forests, and Climate Change has set up a target to sequester two billion tonnes of carbon sequestration by 2030.
The obvious way to achieve these targets seems to plant more trees. However, that might just be counterproductive. As established, wetlands and grasslands can sequester more carbon than many types of forests or wooded areas.
Further, these ecosystems provide many more services from water and food security, to acting as refugia for endangered species. Thus, unscientific planting of trees is a bad idea.
A holistic view is necessary where all intact natural ecosystems are secured and degraded ecosystems are functionally restored.
Also, we should not ignore our marine ecosystems. We have to secure coral reefs, open ocean, and seagrass habitats. We are at a very critical juncture where we have to secure our existing forests, wetlands, grasslands, and seas.
Further, we have to stop tree plantation drives and engage in ecological restoration of degraded ecosystems. If we can achieve this, we will give our 1.4 billion people a sound platform to achieve their aspirations and ensure wellbeing.
Rushikesh Chavan is Head-The Habitats Trust
Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth
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