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Geoengineering and the Paris Agreement

By Dr. Neil Craik and Dr. Wil Burns

In advance of a paper to be released by the Centre for International Governance Innovation, Neil Craik and Wil Burns share thoughts on the potential legal questions that might arise as climate engineering technologies become more salient to international climate change discussions.

Why does geoengineering need to be taken into account when implementing the Paris Agreement?
We think geoengineering is an important consideration, regardless of your views on whether and how climate engineering technologies ought to play a role within the climate regime, because scientists and policymakers are examining the range of policy responses available to the international community. In the event that climate engineering technologies are raised by states in the context of their nationally determined contributions (NDCs) or as a subject of regulation under the rule–making powers of the Paris mechanisms, it will be necessary to understand the extent to which climate engineering proposals fall within the different provisions of the Paris Agreement.

To situate this discussion, in order to meet the Agreement’s objective (outlined in article 2), of keeping global average temperature increase “well below” 2°C above pre-industrial levels while pursuing efforts to limit that increase to 1.5°C, it is likely that significant carbon dioxide removal (CDR) will be required. Almost all of the modelled scenarios for achieving the 2°C objective include a significant deployment of one carbon dioxide removal option, bioenergy with carbon capture and storage (BECCS), towards the middle and end of the century. Certainly, there are 2°C pathways that do not require CDR, but these would require very dramatic emission reductions, straining political and economic feasibility. While the scenarios involving BECCS can be modelled, this does not reflect the feasibility of BECCS or any other CDR technologies, as they would still require significant research and financial support. Moreover, if these technologies are to be implemented at large scales, they would themselves involve significant environmental, social and economic costs. BECCS, for example, has truly staggering land and infrastructure requirements that are likely to have human rights implications.

The risks associated with not achieving the 2°C target has resulted in calls to support further research activities in solar radiation management (SRM) technologies, such as placing aerosols in the stratosphere to reflect sunlight. Here there are legitimate concerns regarding the effect that the prospect of SRM may have on emission reduction commitments, and a very broad range of environmental risks that deployment or even large-scale experimentation may trigger.

In this post we will explore the role of geoengineering in the international legal framework and raise the legal questions and challenges they pose.

What is the place and what are the challenges of Carbon Dioxide Removal (CDR) within the existing international legal framework?
Under article 3 of the Paris Agreement, states are required to identify a range of contributions (NDCs) to address climate change. So long as these contributions are consistent with the underlying articles, there is no express restriction on including climate engineering measures as part of an NDC. It is plausible that a state could include a significant amount of CDR as part of its mitigation contributions under article 4, giving rise to legal concerns about whether such an approach is consistent with the Paris Agreement, notwithstanding its bottom up architecture.

Article 4 implements the 2°C target by identifying the aim of reaching peak global GHG emissions “as soon as possible” with rapid emission reductions to follow, in order to achieve net emissions neutrality (a balance of emissions and removals) by 2050. The definition of “mitigation” includes sinks, which appears to include CDR technologies as they are defined broadly under the UNFCCC to include “any process, activity or mechanism which removes a greenhouse gas”.

In terms of existing practice, many CDR technologies, particularly those that involve bio-sequestration, are already being addressed under the UNFCCC and the Kyoto Protocol as GHG removal mechanisms. For example, carbon capture and storage has been given some standing as an acceptable technology under the Clean Development Mechanism and many parties report on emissions and emission reductions in the context of forests. Scale is often the defining feature that separates CDR from existing GHG removals, but such a distinction would be hard to maintain legally.

What are some outstanding legal questions on CDR technologies?
Notwithstanding the encompassing language of article 4, several legal questions arise.

First, significant uncertainties remain as to the viability of CDR technologies. Thus, a reliance on CDR, particularly in overshoot scenarios (which allow emissions to exceed 2°C levels on the basis of future removals), could be interpreted as being contrary to the non-regression principle and the use of best available science requirement in article 4. The non-regression argument requires reading into article 4 a requirement to continually reduce emissions, as opposed to placing greater reliance on CDR. Some states may want to argue that given the risks associated with overreliance on CDR, there ought to be supplementarity requirements that privilege emission reductions or removals. Further, the requirement to use best available science can be read to require that state NDCs rely only on technologies that are shown to work by reliable scientific data. Over-reliance on unproven technologies may be viewed as contrary to the best available science requirement, and inconsistent with the precautionary principle.

Secondly, there are questions as to the consistency of CDR with the requirement for equity and the emphasis on human rights under the Paris Agreement. To some extent, the argument depends on how much the burdens associated with CDR (like potential diversion of agricultural land or forests for energy production) fall on developing countries and constrain development and poverty alleviation. However, the wording of article 4 requires all states to ensure that their NDCs will not undermine sustainable development aspirations.

What is the need for international cooperation on CDR technologies?
Given the bottom-up architecture of the Paris Agreement, the NDCs themselves may provide little purchase for the regulation of CDR technologies. (The language of article 4 suggests that NDCs are not subject to legal scrutiny by other states.)

However, if CDR technologies move towards implementation, market incentives will be needed to realize their development and scaled deployment. In this regard, there will be a need for international cooperation to address the inclusion of CDR technologies in the market structures anticipated under article 6.

As a result, the formulation of market rules may trigger a debate on the scope and degree of inclusion of CDR technologies as they reach deployment potential. The Paris Agreement does not place express limits on what can be included in the market mechanisms, but the discourse around inclusion will be impacted by the perceived congruence of the technologies with the broader Paris objectives.

Where does Solar Radiation Management (SRM) fit?
SRM technologies should not be considered a form of mitigation since they do not result in emission reductions or removals, though some argue that reducing temperatures could help to enhance sinks. It is possible that SRM options might be viewed as a form of adaptation since they seek to moderate harm from increased GHG concentrations. Technically, SRM addresses climate change itself by influencing the radiative energy balance, as opposed to the effects arising from that change. In this regard, SRM addresses a distinct stage of climate response. It is unlikely that article 7, which addresses adaptation, provides much scope for addressing SRM either permissively or in a constraining manner.

Given the controversy surrounding SRM, there may be pressure for the UNFCCC bodies, including the Paris Agreement decision-making bodies, to address SRM research oversight. There is some scope within the procedural mechanisms of the Agreement to play a role in addressing SRM research governance demands. Certainly, if SRM field research reaches transboundary levels (or arguably where effects exceed some minimum, non-negligible threshold), there will be strong demand for transparent and broadly inclusive oversight. Certainly the SBI/SBSTA forums, or other UNFCCC or Paris Agreement bodies, could facilitate such oversight. For example, one potential avenue is the global stocktaking exercise, which could address questions of technical readiness in relation to both SRM and CDR.

Where do we go from here?
As it stands, climate engineering remains an elephant in the room. It is unmentioned in the Paris Agreement, but present in its implications. The 1.5°C report may provide an opportunity for further reflection on the place of climate engineering as part of a broader portfolio of climate responses. A principal legal challenge going forward will be to ensure a measure of coherence among multiple pathways and approaches to meeting the Paris goals. Climate engineering may complicate this task, but such complications may be unavoidable and are more likely to lead to an internationally integrated approach if they are confronted directly and openly.