In recent months, Germany made headlines as the first major economy to commit to achieving ‘net-negative’ emissions later this century. While the concept of ‘net-zero’ denotes a balance between a country’s emissions and its capacity to remove greenhouse gases from the atmosphere, ‘net-negative’ goes a step further by surpassing emissions with removals.

Achieving ‘net-negative’ emissions signifies more than just halting contributions to climate change; it actively aids in reducing global warming. Many scenarios aiming for the world’s most ambitious climate targets project a transition to net-negative status in the latter half of this century.

However, failing to rapidly curb emissions in the near term could lead to overshooting climate targets, necessitating the removal of billions of tonnes of carbon dioxide (CO2) from the atmosphere later in the century.

Some experts advocate for developed nations to prioritize early attainment of net-negative emissions, citing a moral duty to combat climate change and create room for developing nations to emit as they progress.

Yet, the ability of countries to sequester CO2 is influenced by diverse factors, including land area, forest cover, and population size. Setting distant net-negative targets, however, could divert attention from the urgent task of emission reduction in this decade, according to researchers.

Defining ‘Net-Negative’ Emissions

The Intergovernmental Panel on Climate Change (IPCC) defines ‘net-negative emissions’ as the point at which human-caused greenhouse gas removals surpass human-caused emissions.

It’s important to note that the inclusion of “greenhouse gases” rather than solely focusing on CO2 is significant, as explained by Prof. Joeri Rogelj, an IPCC lead author and climate scientist at Imperial College London. Certain non-CO2 greenhouse gas emissions, such as methane from rice production, pose significant challenges due to the absence of complete elimination technologies.

These emissions, termed ‘residual non-CO2 emissions’ by scientists, make achieving net-zero greenhouse gas emissions more complex. According to Rogelj, reaching net-zero greenhouse gas emissions requires compensatory CO2 removal to counter non-CO2 emissions that are difficult to eliminate.

Therefore, a national target for net-negative greenhouse gas emissions signifies a markedly ambitious goal compared to a net-negative CO2 target over the same period.

Implications for Environmental Engineers

For environmental engineers, the pursuit of net-negative emissions presents multifaceted challenges and opportunities. It necessitates innovative approaches to carbon capture and storage, advancements in sustainable agriculture to mitigate non-CO2 emissions, and the development of scalable technologies for large-scale carbon removal.

Environmental engineers are uniquely positioned to leverage their expertise in carbon sequestration, ecosystem restoration, and renewable energy integration to drive progress towards net-negative emissions. Interdisciplinary collaboration will be critical, involving scientists, policymakers, and stakeholders to deploy effective strategies.

Challenges and Future Outlook

Despite the scientific and technological advancements in carbon removal, several challenges persist. Scaling up carbon sequestration technologies, ensuring their environmental integrity, and addressing policy barriers require concerted efforts.

Looking ahead, environmental engineers will play a central role in designing and implementing solutions to achieve net-negative emissions. This entails continuous innovation, research, and collaboration to realize a sustainable and resilient future.

The concept of ‘net-negative’ emissions has garnered attention, particularly among environmental engineers, as it signifies a critical milestone in climate action. While most countries are far from achieving net-zero emissions, there are notable exceptions, predominantly from the global south, already operating at a net-negative status.

Pioneering Net-Negative Nations

Suriname, Panama, and Bhutan stand out as leaders in achieving net-negative emissions. Suriname, distinguished by its dense forests covering over 97% of its land, sequesters more CO2 than it emits annually. The country’s low population and forest abundance contribute significantly to its net-negative status. However, Suriname emphasizes the need for international support to sustainably manage and protect its forests.

Similarly, Bhutan, renowned for extensive forest cover, has established stringent laws to maintain forest integrity, covering 71% of its land area. Bhutan’s proactive stance on climate action was highlighted when it co-founded the “carbon-negative” club with Suriname during the COP26 climate summit.

Panama, despite facing challenges such as declining tree cover, balances its emissions with substantial CO2 removal from its forests. The country has ambitious goals to restore forest cover and reduce energy emissions, underscoring its commitment to sustainability.

Global North Commitments to Net-Negative Emissions

In recent years, several global north countries have committed to achieving net-negative emissions, signaling a shift towards more ambitious climate targets. Germany’s pledge to attain net-negative greenhouse gas emissions by 2060 reflects the growing recognition that mitigating climate change requires surpassing net-zero targets.

Finland, setting a precedent with its target to achieve net-negative greenhouse gas emissions by 2040, emphasizes the necessity of developed nations taking proactive roles in climate action. Similarly, Denmark aims for net-zero greenhouse gas emissions by 2045 and envisions reaching net-negative emissions by 2050.

Sweden, another frontrunner, committed to reaching net-zero greenhouse gas emissions by 2045, followed by net-negative emissions shortly after. This proactive stance underscores the imperative for global north nations to lead by example in combating climate change.

Policy Implications and Considerations

The debate on whether net-negative emissions are indispensable to meeting global climate goals underscores the urgency of near-term actions. While IPCC scenarios outline pathways to limit global warming without immediate reliance on net-negative emissions, escalating emissions necessitate ambitious measures, including large-scale CO2 removal in the latter half of the century.

Developed nations, acknowledging historical responsibility for climate change, are urged to pursue net-negative targets to create leeway for developing nations to pursue sustainable development pathways. However, equitable distribution of responsibility remains complex, influenced by factors beyond technical capacity.

Environmental engineers play a pivotal role in advancing carbon capture and storage technologies, sustainable land-use practices, and innovative climate solutions. Collaborative efforts across disciplines are imperative to accelerate progress towards achieving net-negative emissions globally.