The glossary of The Intergovernmental Panel on Climate Change (IPCC) defined carbon sink (see sink) as “A reservoir (natural or human, in soil, ocean, and plants) where a greenhouse gas, an aerosol or a precursor of a greenhouse gas is stored. Note that UNFCCC Article 1.8 refers to a sink as any process, activity or mechanism which removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere.” (The Intergovernmental Panel on Climate Change, n.d.).
Picture 1. How Carbon Sink Works
Source: Xcalibur Smart Mapping (n.d.)
We rely on natural carbon sinks—our forests, oceans, and soils—to offset the vast amounts of carbon dioxide (CO₂) that human activity releases into the atmosphere. While carbon sink currently absorb over half of global CO₂ emissions, their capacity to do so diminishes as emissions rise, reducing their effectiveness over time (Levin (WRI) et al., 2021). Research by Ke et al. (2024) shows that the global net land CO₂ sink dropped to 0.44 ± 0.21 GtC per year, its lowest since 2003, due to factors such as droughts in the Amazon and unprecedented wildfires in Canada. Yet, as our emissions continue to increase, the effectiveness of these natural absorbers diminishes. The truth is, we can no longer afford to lean on carbon sinks to bear the weight of our environmental impact alone (Azar & Johansson, 2022, p. 1). Each new study, each piece of research, underscores this reality with clarity and urgency.
The Role and Limits of Carbon Sinks
Forests, oceans, and soils are the planet’s natural systems for capturing and storing carbon. These carbon sinks work by absorbing CO₂, helping to balance the climate by reducing the amount of carbon that would otherwise warm the atmosphere. It’s a service they’ve been performing diligently. For instance, forests alone absorb nearly half of the carbon emissions from fossil fuels, approximately 7.8 ± 0.4 Pg C per year from 1990 to 2019 (Pan et al., 2024). Yet, deforestation, especially in tropical regions, has slashed this benefit, reducing the forest sink’s effectiveness by about two-thirds, or around 2.2 ± 0.5 Pg C per year (Pan et al., 2024).
There’s also an issue of sustainability within carbon sinks. Forests, particularly those recovering from past disturbances, contribute to the global carbon sink in remarkable ways, absorbing around 1.3 Pg C per year in the early 2000s. These young, regrowing forests in northern regions are especially effective at storing carbon due to rapid growth (Pugh et al., 2019, p. 4383). However, this effect is temporary; as forests mature, their carbon uptake tends to decrease (Pugh et al., 2019, p. 4385). This means that carbon sinks must be viewed within their cycles and continuously renewed to remain adaptive enough to handle human-generated carbon emissions.
The Uneven Geography and The Political Dimensions of Carbon Sinks
The geographical differences in carbon sink effectiveness present a unique challenge. Forests in the northern hemisphere, particularly boreal forests, are more efficient in carbon absorption compared to tropical regions, where disturbances like fires and deforestation are more common (Pugh et al., 2019, p. 4386). This uneven distribution makes the task of managing global carbon sinks even more complex. Regions with high carbon sink potential may need tailored strategies that consider both environmental and economic factors, while tropical regions require protection from destructive practices that undermine their carbon storage capacity.
Carbon sink is not just an environmental concern but a critical issue in international relations. Agreements like the Paris Agreement hinge on the contributions of natural carbon sinks to balance global carbon budgets. Nations worldwide include forest conservation, land management, and ocean protection in their climate commitments or nationally determined contributions (NDCs) under these agreements (Liao et al., 2019 & Griscom et al., 2017 in Sha et al., 2022). However, this dependence on carbon sinks brings about a range of diplomatic challenges.
For example, countries with rich forest resources, like Brazil and Indonesia, often face a difficult balance between conserving these resources and fostering economic growth. The international community often advocates for the preservation of these sinks, yet the countries that bear the brunt of conservation are not always compensated adequately, creating tension between developed and developing nations. Wealthier countries may promote preservation without providing the necessary financial support or technology transfer that these developing nations need to manage and protect their natural resources sustainably.
Beyond Carbon Sinks: The Need for Emissions Reduction
As we release more carbon, natural systems like forests and oceans lose their ability to absorb additional CO₂. Rising temperatures also disrupt these processes, as warming changes the biological and chemical reactions that allow these sinks to capture carbon (Azar & Johansson, 2022, p. 4). This creates a troubling cycle: the more carbon we emit, the less effective carbon sinks become, and the more difficult it is for the Earth to keep up with the pace of emissions. Essentially, we’re racing against a system that is constantly being degraded by the very emissions it’s meant to mitigate.
It’s becoming clear that carbon sinks alone cannot carry the burden of our emissions. While they will always play a vital role in climate regulation, we must prioritize reducing emissions at the source. Efforts to protect and enhance carbon sinks, through policies supporting sustainable land management and reforestation, are essential. Yet, these alone will not be enough. We must adopt a more responsible and comprehensive approach to emissions, where we do not rely solely on the Earth to “clean up” our carbon output. Achieving carbon neutrality (CN) will enable an effective response to climate change, support temperature regulation goals, and drive a shift toward a sustainable economic development model (Bai et al., 2023, p. 1).
Toward a Sustainable Future with Global Cooperation
Achieving this balance requires a global commitment. Protecting carbon sinks should be seen not as a national responsibility but as a shared one. Effective climate action will only come through coordinated international efforts. Countries need to support each other—particularly wealthier nations, which contribute the most to global emissions, should provide aid to nations that are home to critical carbon sinks. This support could take the form of financial investment, sustainable technology transfer, and stronger policy frameworks (Pugh et al., 2019, p. 4387).
The vulnerabilities of carbon sinks and the risks we currently face have global and socio-political implications. The inability of carbon sink mechanisms to offset the carbon emissions we produce will affect the targets set by the Paris Agreement. Additionally, this situation could lead to numerous irreversible damages that are likely to disrupt ecosystems and socio-political systems worldwide, such as ice melt, rising sea levels, widespread natural forest fires, uncontrolled and irregular wildlife migration, and the emergence of pandemics and infectious diseases.
Conclusion
We can no longer rely solely on carbon sink mechanisms to manage the carbon emissions we produce. Addressing the climate burden requires a serious reduction in carbon emission production. After all, we cannot keep benefiting from nature’s resources without a sense of responsibility. If we do, exploitation would not be an exaggeration to describe humanity’s greed.
Mapping out the roles of Northern and Southern countries is not meant to create disparities but rather to clarify distinct roles and responsibilities to help restore the optimal function of carbon sinks. Cooperation—whether North-South, South-South, or North-North—should not be an issue. The real problem arises if Northern countries, which contribute the most to global carbon emissions, do not become self-aware enough to challenge the materialistic paradigm in conventional economics, where profit is prioritized over other considerations.
Reflecting on the journey toward understanding carbon sinks and their complexities, I believe that sustainable carbon sink management is not just a scientific or environmental issue—it’s a question of global responsibility. We cannot continue reaping the benefits of natural systems without acknowledging the price. The pathway to a balanced climate does not lie in burdening carbon sinks alone but in recognizing that every nation, industry, and individual has a role in emissions reduction and environmental stewardship. If we’re serious about achieving a stable climate, this journey will require collective effort, discipline, and empathy across nations and generations.
References
Azar, C., & Johansson, D. J. A. (2022). IPCC and the effectiveness of carbon sinks. Environmental Research Letters, 17(4), 041004. https://doi.org/10.1088/1748-9326/ac5bb2
Bai, X., Zhang, S., Li, C., Xiong, L., Song, F., Du, C., Li, M., Luo, Q., Xue, Y., & Wang, S. (2023). A carbon-neutrality-capacity index for evaluating carbon sink contributions. Environmental Science and Ecotechnology, 15, 100237. https://doi.org/10.1016/j.ese.2023.100237
Ke, P., Ciais, P., Sitch, S., Li, W., Bastos, A., Liu, Z., Xu, Y., Gui, X., Bian, J., Goll, D. S., Xi, Y., Li, W., O’Sullivan, M., De Souza, J. G., Friedlingstein, P., & Chevallier, F. (2024). Low latency carbon budget analysis reveals a large decline of the land carbon sink in 2023. National Science Review, nwae367. https://doi.org/10.1093/nsr/nwae367
Levin (WRI), K., Waskow (WRI), D., & Gerholdt (WRI), R. (2021). 5 Big Findings from the IPCC’s 2021 Climate Report. https://wri-indonesia.org/en/insights/5-big-findings-ipccs-2021-climate-report
Pan, Y., Birdsey, R. A., Phillips, O. L., Houghton, R. A., Fang, J., Kauppi, P. E., Keith, H., Kurz, W. A., Ito, A., Lewis, S. L., Nabuurs, G.-J., Shvidenko, A., Hashimoto, S., Lerink, B., Schepaschenko, D., Castanho, A., & Murdiyarso, D. (2024). The enduring world forest carbon sink. Nature, 631(8021), 563–569. https://doi.org/10.1038/s41586-024-07602-x
Pugh, T. A. M., Lindeskog, M., Smith, B., Poulter, B., Arneth, A., Haverd, V., & Calle, L. (2019). Role of forest regrowth in global carbon sink dynamics. Proceedings of the National Academy of Sciences, 116(10), 4382–4387. https://doi.org/10.1073/pnas.1810512116
Sha, Z., Bai, Y., Li, R., Lan, H., Zhang, X., Li, J., Liu, X., Chang, S., & Xie, Y. (2022). The global carbon sink potential of terrestrial vegetation can be increased substantially by optimal land management. Communications Earth & Environment, 3(1), 8. https://doi.org/10.1038/s43247-021-00333-1
The Intergovernmental Panel on Climate Change. (n.d.). Glossary—Global Warming of 1.5 oC. Retrieved October 31, 2024, from https://www.ipcc.ch/sr15/chapter/glossary/
Xcalibur Smart Mapping. (n.d.). Natural Carbon Sink. Xcalibur Smart Mapping. Retrieved October 31, 2024, from https://xcaliburmp.com/solution/smart-natural-carbon-sink/