Addressing climate change is a daunting and urgent task for humanity. While drastically reducing greenhouse gas emissions to mitigate climate change is the cornerstone of the solution, scientists have acknowledged that complementary measures will be needed, due to the unavoidable residual emissions. This has brought increased attention to climate-altering technologies and measures (CATM), also known as geoengineering, which could remove residual emissions or counteract the disruptions and heating they cause. How these instruments will be governed at the global level is an important question in climate governance.
Definition and Rationale of CATM
Climate-altering technologies and measures (CATM) – also sometimes referred to as climate or geo-engineering – refer to a broad set of methods and technologies that aim to deliberately alter the climate system in order to alleviate the impacts of climate change (IPCC, 2014). These methods can be classified into two groups. Carbon Dioxide Removal (CDR) focuses on absorbing carbon from the atmosphere and increasing carbon sinks at a scale sufficiently large to alter the climate. Solar Radiation Management (SRM) aims at limiting the amount of absorbed solar energy in the climate system, for example by increasing the reflectivity of the earth’s surface or injecting aerosols into the stratosphere.
Although mitigation strategies are the heart of global action to tackle climate change, scientists and policymakers acknowledge that even drastic emission reductions over the next years will not be sufficient to keep temperature rise under desired levels. No pathway envisioned by the IPCC could limit global warming under 1.5°C without the use of CDR (IPCC, 2018). Similarly, it is highly unlikely that mitigation efforts alone with be sufficient to stay under the 2°C target set by the Paris Agreement (Edmonds et al., 2013).
This section provides resources to understand the nature and relevance of CATM in the fight against climate change.
- Geoengineering Technologies explained | Heinrich Boell Foundation
- Interactive geoengineering map | ETC Group and Heinrich Boell Foundation
- Carbon Dioxide Removal: infographics & publications | Carnegie Council for Ethics in International Affairs
- Solar Radiation Modification: infographics & publications | Carnegie Council for Ethics in International Affairs
- Geoengineering Monitor
- Solar geoengineering — climate-solution or Pandora’s box? | Alistair Walsh | DW News | 24 July 2023
- One Atmosphere: An independent expert review on Solar Radiation Modification research and deployment | UNEP | 27 March 2023
- We don’t need ‘miracle’ technologies to fix the climate. We have the tools now | Mark Z Jacobson | The Guardian | 7 February 2023
- Debunking Solar Geoengineering | Project Syndicate | 9 December 2022
- Les nouvelles technologies à tout prix ? | Magazine L’Environnement | Swiss Federal Office for the Environment (FOEN) | 1 December 2021
- Decarbonisation technologies also address other environmental problems | Geneva Solutions | 2 June 2021
- What if we could engineer the planet to help fight climate change? | European Parliament | 23 February 2021
- Geoengineer the Planet? More Scientists Now Say It Must Be an Option | Yale School of Environment | 29 May 2019
- Geoengineering to Combat Global Warming | UNEP global environmental alert service | May 2011
The Science behind CATM
In the Fifth Assessment Report (AR5) published in 2014, the IPCC produced several new scenarios which included CDR measures. In the Special Report on Global Warming of 1.5°C Report, scenarios achieving the 1.5°C target include the removal of in the order of 100 to 1,000 billion tonnes of CO2 from the atmosphere in the next 80 years. In both reports, these measures are presented as important to achieving ambitious climate mitigation. Yet, it is underlined that they do not present an alternative to immediate action to reduce greenhouse emissions. Furthermore, there are currently no CDR techniques ready to be deployed at the scale necessary to significantly contribute to meeting the Paris Agreement goals.
SRM is not included in any of the IPCC scenarios, but discussions on its uncertainties, side effects, risks, governance, and ethical implications have been seen in both the AR5 and the 1.5°C Report. However, UNEP’s independent expert review on SRM research and deployment (One Atmosphere: UNEP, 2023) has highlighted new risks caused by SRM deployment at scale, including damages to the ozone layer and increase or redistribution of climate change impacts on society and ecosystems.
The section provides resources on the state of science on CATM.
- Special Report on Global Warming of 1.5 °C | IPCC | 8 October 2018
- Carbon Dioxide Removal and Solar Radiation Management Geoengineering Technologies: Possible Roles, Options, Risks and Status | IPCC | AR5 Synthesis Report: Climate Change 2014
- Geoengineering may be used to combat global warming, experts say | The Guardian | 8 October 2018
- IPCC mention of geoengineering, though brief, opens window for discussion | Environment Defense Fund | 30 October 2013
International Governance of CATM
As CATMs are being developed and tested, there is a growing need for global frameworks to address the issue as the impacts will transcend borders. At the 2017 UN Climate Change Conference (COP23), experts expressed the need to discuss the governance of CATM, especially in relation to stratospheric aerosol injection (SAI), due to the great uncertainties and potential side effects of these measures (UN News, 2017).
Given the numerous unknowns, risks and gaps in research, some have identified a strong need to establish an international scientific review process to identify scenarios, consequences, uncertainties and knowledge gaps (UNEP, 2023). Such research requires an equitable, transparent, diverse and inclusive discussion of the underpinning science, impacts, risks, uncertainties and governance, should they be deployed.
Immediate and meaningful steps may need to be taken to lay a foundation for a decision process regarding the research, policy, regulation, and possible use of CATM. This section outlines current discussions on governance issues among international actors in Geneva and beyond.
- List of Useful Resources on Geoengineering | CIEL, Earthjustice, QUNO, SGI, TWN, etc Group, and FIAN International
- SRM and Youth Perspectives on its Governance | UNECE Side Event 2023 | 16 May 2023
- CIEL Welcomes Mexican Government Announcement on Solar Geoengineering Ban | CIEL | 17 January 2023
- Managing the Risks from an Increasingly Likely Overshoot of 1.5°C – The role (if any) of solar radiation modification | C2G | 12 December 2022
- Should we talk about solar geoengineering? | Geneva Solutions | 17 October 2022
- How can multilateral processes shape the governance of climate-altering approaches? | C2G Talk with Franz Perrez | 16 February 2021
- A call for better governance of climate engineering technologies | EPFL | 19 June 2020
- International Governance Issues on Climate Engineering – GENeva Environment Dialogues | Geneva Environment Network | 18 June 2020
- International Governance Issues on Climate Engineering | International Risk Governance Center (IRGC), Ecole polytechnique fédérale de Lausanne (EPFL) | June 2020
- Carnegie Climate Governance Initiative | Carnegie Council for Ethics in International Affairs
- Carbon Dioxide Removal and its Governance – Evidence Brief | Carnegie Council for Ethics in International Affairs | 2 March 2021
- Governing large-scale carbon dioxide removal: are we ready? – an update | Carnegie Council for Ethics in International Affairs | February 2021
- Potential implications of carbon dioxide removal for the sustainable development goals | Matthias Honegger, Axel Michaelowa and Joyashree Roy | Climate Policy | November 2020
- Governing Solar Radiation Modification – Policy Brief | Carnegie Council for Ethics in International Affairs | 26 November 2020
- Governing Large-Scale Carbon Dioxide Removal – Policy Brief | Carnegie Council for Ethics in International Affairs | 21 November 2019
- Options for supporting Carbon Dioxide Removal – Discussion paper | New Climate Institute | July 2020
- Governing Solar Radiation Modification – Evidence Brief | Carnegie Council for Ethics in International Affairs | 21 January 2020
- Geoengineering-Governance | German Environment Agency | 16 October 2019
- Governing Nature-Based Solutions to Carbon Dioxide Removal – Evidence Brief | Carnegie Council for Ethics in International Affairs | 24 September 2019
- Solar geoengineering to reduce climate change: a review of governance proposals | Jesse L. Reynolds | Proceedings of the Royal Society | 4 September 2019
- Carbon Removal and Solar Geoengineering: Potential implications for delivery of the Sustainable Development Goals | Carnegie Council for Ethics in International Affairs | May 2018
Perspectives on Solar Radiation Modification
An event that had taken place ahead of the sixth session of the UN Environment Assembly (UNEA-6) — the world’s highest decision-making body on the environment, taking place from 26 February to 1 March 2023 — aimed to take stock of recent publications referring to SRM. These include the UNEP Independent Expert Review on solar radiation modification research and deployment, the report of the Human Rights Council Advisory Committee on the impact of new technologies for climate protection on the enjoyment of human rights (A/HRC/54/47), the UN Convention on Biological Diversity on certain restrictions on solar insolation activities that may affect biodiversity (CBD/DEC/X/33/8w), and mentions of SRM in reports of the Intergovernmental Panel on Climate Change.
The event, Perspectives on Solar Radiation Modification Governance, organized by Switzerland within the framework of the Geneva Environment Network, brought together stakeholders from different fields to provide their perspectives on solar radiation modification governance. A draft resolution on solar radiation modification was submitted by Guinea, Monaco, Senegal and Switzerland for UNEA-6.
CATM at UNFCCC and the Paris Agreement
The United Nations Framework Convention on Climate Change (UNFCCC) is the main global forum aimed at addressing climate change. The agreements under the UNFCCC could significantly shape the governance of CATM. The 1997 Kyoto Protocol alluded to CDR, as it stated that Parties should promote research, development and increased use of carbon dioxide sequestration technologies (Art. 2.1.a.iv).
The Paris Agreement, adopted by the Parties in 2015, has spurred further interest in CATM in climate policy discussions, although these measures are not explicitly mentioned in the agreement. The ambitious target of limiting global warming under 2°C – which is unlikely to be achieved without substantial implementation of CDR measures – and the mention of greenhouse gas removal as a potential mean to achieve this target have contributed the growing interest for CATM. There have been to date no discussions of SRM under the UNFCCC.
Parties aim to reach global peaking of greenhouse gas emissions as soon as possible, recognizing that peaking will take longer for developing country Parties, and to undertake rapid reductions thereafter in accordance with best available science, so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century, on the basis of equity, and in the context of sustainable development and efforts to eradicate poverty.
This section provides additional resources on discussions of CATM under the UNFCCC.
- Bonn: Climate engineering is risky, but should be explored, experts say at UN conference | UN News | 16 November 2017
- Paris Agreement | UN | 2015
- Implications of the Paris Agreement for Carbon Dioxide Removal and Solar Geoengineering | Joshua B. Horton, David W. Keith, and Matthias Honegger | Harvard Project on Climate Agreements | July 2016
CATM and Biodiversity
Some Nature-Based Solutions (NBS) seek to exploit natural systems capacities to absorb and store carbon through actions such as planting trees and improving soils. The 2019 IPBES Report underscores that nature-based solutions will be ‘indispensable’ to achieving climate targets. It concludes that these may ‘provide 37 per cent of climate change mitigation until 2030 needed to meet the goal of keeping climate warming below 2°C, with likely co-benefits for biodiversity’. It further notes that ‘more transdisciplinary research and sharing of knowledge among appropriate institutions are needed in order to better understand the impacts of climate-related climate engineering on biodiversity and ecosystem functions and services, socio-economic, cultural and ethical issues and regulatory options’. (IRGC/EPFL, 2020)
By significantly altering the earth’s climate, the implementation of CATM would have tremendous impacts on ecosystems and biodiversity. In 2010, the contracting Parties to the Convention on Biological Diversity (CBD) agreed on a temporary moratorium stating that “no climate-related geo-engineering activities that may affect biodiversity take place, until there is an adequate scientific basis on which to justify such activities” (CBD, 2010). While this position was reaffirmed in 2016, it does not cover all forms of carbon storage or small-scale experiments, is not binding, and country participation in the CBD is not universal (e.g. it is not ratified by the United States).
- CBD COP15 needs to reinforce precaution against geoengineering to protect biodiversity and communities | ETC Group | 11 December 2022
- Nature-Base Approaches to large-scale Carbon Dioxide Removal (various resources) | Carnegie Council for Ethics in International Affairs | 2021
- Governing Nature-Based Solutions to Carbon Dioxide Removal – Evidence Brief | Carnegie Council for Ethics in International Affairs | 2019
- Knowledge gaps on climate-related geoengineering in relation to the Convention on Biological Diversity (CBD) – Technical Briefing Paper | Carnegie Council for Ethics in International Affairs | 4 July 2018
- Geoengineering and Biodiversity: Policy and Research Implications | Forum for Climate Engineering Assessment | February 2018
- Geoengineering carries ‘large risks’ for the natural world, studies show | Carbon Brief | 22 January 2018
- Climate-related Geoengineering and Biodiversity | CBD | 23 March 2017
- CBD Report Highlights Uncertainties of Geoengineering Assessment | IISD | 10 November 2016
- Impacts of Climate-Related Geoengineering on Biological Diversity | CBD | 5 April 2012
- Reviewing the potential impacts of geoengineering on ecosystems and biodiversity | Cambridge Conservation | 2011
CATM and the Oceans
Marine CATM refers to all activities that intend to manipulate the marine environment, for the purposes of combatting the effects of climate change. One of the most common discussed method is ocean fertilization, the practice of introducing considerable quantities of iron compounds into the ocean to trigger algal bloom across large areas. Debates remain about the potential of such methods to effectively store CO2 and the associated risks.
Since 1999, contracting Parties to the London Convention and London Protocol have taken steps to address ocean fertilization. In April 2013, a proposal to amend the London Protocol to regulate the placement of matter for ocean fertilization and other marine geoengineering activities was accepted. This section offers resources on the various governance mechanisms and discussions around marine climate engineering.
- Marine geoengineering | IMO
- Ocean Fertilization under the LC/LP | IMO
- Ocean Fertilization – Governance and Policy | Ocean Carbon & Biogeochemistry (OCB) Project
- Emerging Marine Climate Techniques (various resources) | Carnegie Council for Ethics in International Affairs | 2020
- Governing Marine Carbon Dioxide Removal and Solar Radiation Modification – Evidence Brief | Carnegie Council for Ethics in International Affairs | 2019
- High Level Review of a Wide Range of Proposed Marine Geoengineering Techniques | GESAMP | 2019
- Governance of Marine Geoengineering | Centre for International Governance Innovation | 2019
- Precautionary approach over marine geoengineering | WMO | 14 March 2019
- Marine and social scientists are urging a precautionary approach towards marine geoengineering techniques which involve deliberate large-scale manipulation of the environment | Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection | 12 March 2019
- Geoengineering the oceans: an emerging frontier in international climate change governance | Jeffrey McGee, Kerryn Brent et al. | Australian Journal of Maritime & Ocean Affairs | 9 November 2017
- Ocean fertilization: a scientific summary for policy makers | UNESCO Intergovernmental Oceanographic Commission | 2010
CATM at the UN Environment Assembly
The United Nations Environment Assembly (UNEA) is the world’s highest-level decision-making body on the environment. At the fourth annual meeting of UNEA in March 2019, a resolution on ‘Geoengineering and its Governance’, put forward by Switzerland with the support of several other member States, was discussed. The resolution requested that the Executive Director of the UN Environment Programme prepare an assessment of CATM, in particular CDR and SMR. Although the revised resolution was ultimately withdrawn for lack of agreement, further discussions on the topics can be expected in further UNEA processes. This section provides resources on the negotiations on CATM at UNEA.
- The Role of the United Nations Environment Assembly in Emerging Issues of International Environmental Law | Franz Perrez | University of Bern & Swiss Federal Office for the Environment | 15 July 2020
- Geoengineering debate shifts to UN environment assembly | Nature News | 7 March 2019
- Switzerland puts geoengineering governance on UN environment agenda | Climate Home News | 26 February 2019
CATM and Human Rights
While there is no doubt that climate change itself threatens the effective enjoyment of various human rights, it is equally important to consider the human rights implications of the measures that are to be implemented to address climate change. At its 48th session in October 2021, the Human Rights Council adopted a mandate for a Special Rapporteur on climate change. The resolution also requests the Advisory Committee to conduct a study on the impact of new technologies for climate protection on the enjoyment of human rights and submit a report to HRC54 in September 2023.
In April 2022, the Advisory Committee issued a call for inputs on the matter. At the 28th Session of the committee in August 2022, experts discussed the preliminary outline for the study. NGOs have raised concerns about the terminology used in the report, emphasizing the importance of differentiating CATM from other proven technologies, like renewable energy, and of critically assessing the impacts of CATM on human rights.
- Impact of new technologies intended for climate protection on the enjoyment of human rights ( Advance Unedited Version) | Report of the Human Rights Council Advisory Committee | August 2023
- List of Useful Resources on Geoengineering | CIEL, Earthjustice, QUNO, SGI, TWN, etc Group, and FIAN International
- Geoengineering & Human Rights | HRC51 Side-event organized by CIEL with support from Earthjustice, QUNO, SGI, TWN, etc Group, and FIAN International | 13 September 2022
- Impact of new technologies for climate protection on the enjoyment of human rights – Preliminary outline and research questions | HRC Advisory Committee | August 2022
- Statement on the impact of new technologies for climate protection | CIEL | 9 August 2022
- Impact of new technologies for climate protection on the enjoyment of human rights – Call for inputs | OHCHR | April 2022
- Solar Geoengineering Non-Use Agreement
An initiative calls for an International Non-Use Agreement on Solar Geoengineering, highlighting how solar geoengineering deployment at planetary scale cannot be fairly and effectively governed in the current system of international institutions, as it also poses unacceptable risk if ever implemented as part of future climate policy. The Non-Use Agreement now has endorsements by various organizations across the world.
- Refroidir le climat, une idée qui se réchauffe | Denis Delbecq | Le Temps | 2 March 2023
Après que des expériences d’injection de soufre dans la stratosphère ont été réalisées en catimini, des voix de plus en plus nombreuses s’élèvent pour défendre – ou contester – les recherches sur le refroidissement du climat