Athulya Premachandran, a social impact researcher, writes about carbon sequestration and the importance of increasing green cover and preserving biodiversity.
“It's too hot! I got completely drained today…”, this lament has become all too common nowadays, echoing through our daily conversations, whether it is during lunch with colleagues, while having dinner with family, or even just chatting with a stranger. Many of us our also becoming increasingly aware of the reason behind these long heat spells: Global warming, the phenomena of increase in high levels of carbon dioxide, a heat-trapping gas, in the atmosphere.
Although carbon dioxide is naturally present in the atmosphere, human activities such as land-use change, deforestation, biomass burning, wetland draining, soil cultivation, and fossil fuel combustion have led to a rise in global warming of 1.5°C above pre-industrial levels. The concentration of atmospheric CO2 has increased 48% from an average of 280 parts per million (ppm) in the 1700s to over 415 ppm in 2021. Since carbon dioxide remains in the atmosphere for centuries, atmospheric levels can remain high for some time, even if emissions decline or stop altogether.
To address this challenge of escalating levels of atmospheric CO2, The Paris Agreement was established during the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change in December 2015. It represented a landmark global initiative involving over 196 countries committed to limiting the global temperature increase to less than 2 degrees Celsius above pre-industrial levels by 2100, with a more ambitious goal of staying below a 1.5-degree increase.
The agreement signified a crucial step towards a zero-emission world and is pivotal in achieving the Sustainable Development Goals.
Some of the ways through which governments and corporations can reduce CO2 emissions:
There are three key ways to reduce CO2 emissions and combat climate change:
(a) Reducing global energy use,
(b) Developing low or no-carbon fuel technologies, and
(c) Sequestering CO2 from point sources or the atmosphere through natural and engineering techniques.
For this article, let’s focus on carbon sequestration!
What is Carbon Sequestration?
Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide. The process can be both natural as well as artificial. Natural carbon sequestration happens when CO2 is stored in vegetation, soils, and oceans, with forests and grasslands acting as significant carbon sinks. Artificial sequestration techniques include carbon capture and storage (CCS) and bioenergy with carbon capture and storage (BECCS). These innovative methods address the pressing need for effective climate change mitigation.
Trees, the master carbon sequesters!
Trees act as crucial carbon sinks, playing a vital role in the global carbon cycle. Covering extensive areas of the planet, tree communities offer essential goods and services, serving as carbon sinks, releasing oxygen, providing habitat, and contributing to soil retention. Their natural mechanisms, particularly carbon sequestration, significantly reduce atmospheric CO2 levels.
This sequestration occurs through both long-term geological processes, involving biogeochemical cycling among the biosphere, atmosphere, soil, and oceans over thousands of years, and short-term cycles that involve storing carbon in trees within various land uses such as forests, agroforestry systems, and agricultural lands over decades and centuries.
Trees capture carbon dioxide through photosynthesis and store it as Above-Ground Biomass (AGB) and Below-Ground Biomass (BGB), which includes roots, soil microbes, and subsurface layers. Forests, primarily composed of trees, contribute 80% of global carbon annually. They play a critical role in carbon sequestration and serve as essential tools for climate change mitigation, while also providing additional benefits such as habitat preservation, water quality improvement, recreational spaces, and wood products.
Maintaining and enhancing biodiversity in tree-rich ecosystems enhances resilience to human-induced pressures and climate change impacts. Biodiversity considerations at various scales and elements, from genes to communities, are crucial for the success of carbon sink projects, including afforestation, restoration, and emission reduction initiatives focused on forest conservation and management.
Carbon Farming & Carbon Credits
Carbon farming is one of the eco-friendly techniques aimed at increasing carbon sequestration in soil, thereby mitigating CO2, CH4, and N2O emissions. This process, also known as abatement, involves practices like storing carbon in soils through reforestation and regrowth, incorporating carbon-negative biochar, and substituting biofuels for fossil fuels. Land managers can earn carbon credits by reducing emissions on their land and selling these credits to government authorities. Carbon farming is a voluntary scheme providing economic incentives for emissions reduction. It involves sequestration and emissions avoidance, enhancing the removal of CO2 from the atmosphere.
Carbon credits, introduced through international treaties to limit greenhouse gas production, allow businesses to trade and balance emissions globally, motivating eco-friendly practices. The carbon credit system, ratified with the Kyoto Protocol, aims to halt CO2 emission increases. Credits, equivalent to one tonne of CO2 or its GHG equivalent, can be bought and sold globally, fostering sustainable business practices, and contributing to emissions reduction goals.
The functional relationship between diversity, carbon storage, and sequestration holds significant implications for effective project management in the global effort to mitigate climate change through the conservation of natural ecosystems.
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