Carbon Dioxide Removal: An Essential Pathway to Net Zero

As the impacts of climate change grow more severe, addressing the root causes of global warming has become a top priority for nations, businesses, and communities. While reducing greenhouse gas (GHG) emissions is critical, it has become increasingly clear that this alone will not be sufficient to mitigate the worst effects of climate change. The scientific consensus underscores the need to remove vast amounts of carbon dioxide (CO₂) from the atmosphere.

This process, known as Carbon Dioxide Removal (CDR), represents a pivotal opportunity to stabilize the climate, complement emission reduction efforts, and build a sustainable future. As an essential pillar of global climate action, CDR offers not only a pathway to achieving net-zero emissions but also a means to unlock environmental, economic, and social benefits.

This blog delves into the importance of CDR, the methods available, and the key challenges and opportunities it presents.

The Growing Need for Carbon Dioxide Removal

Global climate agreements, such as the Paris Accord, have set ambitious targets to limit global temperature rise to 1.5°C above pre-industrial levels. However, despite decades of progress in renewable energy, energy efficiency, and decarbonization, the harsh reality is that many emissions are difficult or impossible to eliminate entirely.

Industries such as aviation, shipping, cement production, and steel manufacturing produce what are known as "hard-to-abate" emissions. These sectors face significant technological and economic barriers to complete decarbonization. As a result, achieving net-zero emissions requires balancing the CO₂ we emit with the CO₂ we remove from the atmosphere.

To meet the Paris targets, scientists estimate that we need to remove approximately 10 gigatons of CO₂ annually by the middle of this century. To put this figure in perspective, it represents roughly one-quarter of current global emissions. This challenge is monumental, requiring both bold action and transformative innovation.

Natural systems, such as forests, wetlands, and oceans, already absorb a significant amount of CO₂ each year. However, their capacity is finite and under increasing pressure from deforestation, pollution, and other human activities. Moreover, these natural processes work on timescales of decades to centuries, which are insufficient to meet the urgent timelines required by climate science.

This is where Carbon Dioxide Removal technologies enter the equation. By leveraging both natural and engineered approaches, CDR offers a way to address residual emissions, support long-term climate stability, and enhance the resilience of ecosystems and economies alike.

Understanding Carbon Dioxide Removal

CDR encompasses a diverse range of methods designed to remove CO₂ from the atmosphere and store it permanently. These methods can be broadly categorized into two main approaches:

1. Nature-Based Solutions

Nature-based solutions harness the power of ecosystems to absorb and store CO₂. These methods are often more cost-effective and deliver additional benefits for biodiversity, water quality, and soil health. Examples include:

• Afforestation and Reforestation: Planting trees in deforested or non-forested areas to capture CO₂ and store it in their biomass. While effective, these methods require careful planning to avoid competition with agriculture and ensure long-term carbon storage.
• Soil Carbon Sequestration: Enhancing the organic carbon content of soils through sustainable agricultural practices such as no-till farming, cover cropping, and compost application. These techniques improve soil health while locking away carbon for decades.
• Wetland and Peatland Restoration: Restoring these ecosystems to their natural state can significantly enhance their carbon storage capacity while providing critical habitat for wildlife and protecting against flooding.

2. Technological Solutions

Technological solutions use engineered systems to remove CO₂ directly from the atmosphere. Although these methods are still developing, they hold great promise for scalability and durability. Examples include:

• Direct Air Capture (DAC): Machines equipped with filters and chemical reactions extract CO₂ directly from the air, which is then stored underground or used in industrial processes. While energy-intensive, DAC has the advantage of requiring minimal land use.
• Bioenergy with Carbon Capture and Storage (BECCS): Combines bioenergy production with CO₂ capture and underground storage, offering a dual benefit of energy generation and carbon removal.
• Enhanced Rock Weathering: Accelerates the natural process of carbon mineralization by spreading finely crushed minerals over land, where they react with atmospheric CO₂ to form stable carbonates.

Both approaches—nature-based and technological—offer unique benefits and trade-offs. Nature-based solutions provide co-benefits for ecosystems and communities but are susceptible to risks like wildfires or deforestation. Technological methods are more permanent but require significant investment to overcome challenges related to cost, energy use, and scalability.

Overcoming Challenges to Scale Carbon Dioxide Removal

Despite its potential, CDR faces significant hurdles that must be addressed to unlock its full impact:

1. Scalability and Cost:

   Scaling up CDR technologies to meet the 10-gigaton target will require unprecedented investment in research, infrastructure, and deployment. Nature-based solutions like reforestation are already being implemented at scale but may face competition with agriculture and urban development. Technological solutions, such as DAC, remain prohibitively expensive, costing up to $700 per ton of CO₂ removed. By comparison, forestry-based projects cost as little as $15 per ton.

2. Carbon Accounting and Transparency:

   Accurate measurement, reporting, and verification (MRV) are critical to ensuring that CDR projects deliver real and additional benefits. Standardized carbon accounting methods will build trust and allow businesses, policymakers, and investors to make informed decisions.

3. Policy and Market Support:

   Robust policy frameworks are essential to incentivize investment in CDR. Governments can play a pivotal role by integrating CDR into emissions trading systems (ETS), offering subsidies, and setting clear regulatory standards. For example, New Zealand has successfully incorporated forestry-based removals into its national ETS, providing a strong incentive for land restoration projects.

4. Durability and Permanence:

   Ensuring that removed CO₂ stays out of the atmosphere over the long term is vital. While technological methods like geological storage offer high permanence, nature-based solutions can be vulnerable to reversal through events like wildfires, floods, or human activity. Innovative solutions, such as carbon insurance mechanisms, can help mitigate these risks.

The Co-Benefits of Carbon Dioxide Removal

Beyond its role in mitigating climate change, CDR delivers a wide range of environmental, economic, and social benefits:

• Environmental Benefits: Many CDR methods restore ecosystems, protect biodiversity, and improve soil and water quality. For example, biochar enhances soil fertility while sequestering carbon.
• Economic Benefits: The development of CDR technologies stimulates innovation, creates jobs, and generates economic value through carbon credits and new markets.
• Social Benefits: By enhancing climate resilience, CDR can protect vulnerable communities from the impacts of extreme weather, support food security, and create sustainable livelihoods.

Looking Ahead

Carbon Dioxide Removal represents a transformative opportunity to stabilize the climate and build a sustainable future. However, it is not a substitute for reducing emissions. Both strategies must work hand-in-hand to achieve climate goals.

By investing in diverse CDR approaches—ranging from reforestation to advanced technologies like DAC—we can create a robust portfolio of solutions that address the unique challenges of different regions and industries. This will require collaboration across governments, businesses, academia, and civil society to accelerate innovation, scale deployment, and ensure equity in the benefits of CDR.

Conclusion

The road to net zero is complex, but Carbon Dioxide Removal offers a clear and actionable pathway to achieving our climate goals. By integrating CDR into broader climate strategies, we can turn the challenge of managing CO₂ into an opportunity for environmental, social, and economic progress.

This blog is inspired by insights from Jazmin Mota-Nieto’s article, Carbon Dioxide Removal: A Key Pillar of Carbon Management and Sustainability (Oxford Institute for Energy Studies, 2024).