The developed countries of the “global north” are responsible for 92% of excess global emissions, according to a 2020 study in The Lancet Planetary Health. Yet it is the rest of the world – the “global south” – that disproportionately bears the brunt of climate change. Emergency measures to reflect more of the Sun could help temporarily avoid the worst impacts, but it must serve to improve the safety of those most affected.

Elil Hoole

Shaun Fitzgerald

The developed countries of the “global north” are responsible for 92% of excess global emissions, according to a 2020 study in 

. Yet it is the rest of the world – the “global south” – that disproportionately bears the brunt of climate change. Emergency measures to reflect more of the Sun could help temporarily avoid the worst impacts, but it must serve to improve the safety of those most affected.

Somewhere between 15% and 40% of CO₂ emissions will remain in the atmosphere 

so much climate change is already “locked in”

, any strategy to tackle it based on emissions reduction alone, regardless of how quickly we reduce them, would still result in catastrophic ice losses in the Arctic and Antarctica leading to sea level rise, loss of low-lying countries and hundreds of millions of climate refugees. It would still mean global food and water shortages, massive flooding and wild fires, and a permanent loss of ecosystems. These devastating changes will continue to disproportionately impact the global south.

We believe the best way to avert major disaster is to develop and deploy temporary schemes which can partially shield some of the Earth from incoming solar radiation, at least until emissions reductions and carbon capture and storage can be scaled up.

There are two main approaches which have very different characteristics. The first involves releasing small reflective particles into the upper atmosphere, which would reflect sunlight back into space. Known as “stratospheric aerosol injection”, this process would cool the globe for several years or more, but it is controversial because of the potential for global and long-lasting 

The other approach, “marine cloud brightening”, involves ships generating sea spray. The water droplets evaporate and the resulting salt crystals get carried up into the air. This gives clouds something to form around, and helps cool the planet since the clouds formed by small salt crystals reflect more of the Sun’s energy.

As these particles are returned to the ocean in a matter of weeks, it is much easier to “turn off” cloud brightening if ever it was deemed necessary. Together with its potential to be deployed on a more regional basis, this makes it more likely to be acceptable to the public and policymakers.

Most of what we understand about these technologies come from computer simulations known as climate models. There have been some real-world experiments, however. For instance China has injected particles in the atmosphere to try and seed new clouds and 

 to prevent it melting. In Peru, authorities once 

 in order to reflect more heat and protect its glacier (darker colours are more absorbent). There are plans to protect Australia’s Great Barrier Reef with 

These initial steps give us valuable insights into the possibilities and limitations of these technologies. But further funding and research is needed to 

There are technical questions to be addressed, but there are also critical social science issues – research will need to examine the contexts in which these kinds of technology develop, with a focus on dimensions of gender, ethics, justice, equity and sustainable development among communities most affected by climate change. Research collaborations and governance mechanisms must evolve to provide space for leadership from these communities, which will in turn strengthen global capacities to develop and deploy safe, inclusive technologies as an intermediate solution to climate change.

The cost of climate injustice cannot be easily quantified. However, communities least able to adapt, perhaps due to a lack of resources, pre-existing conflicts, or because they’re based in an area already prone to droughts or hurricanes, may well argue that no amount of climate change is safe. Technological advancements such as marine cloud brightening mean there is a potential pathway to avert catastrophe and this needs to be further developed.

If we place human life and global environmental security at the heart of our response, we must explore potential technologies that could save countless lives and stave off the worst impacts of climate change until mitigation policies catch up with reality. But crucially, decisions on how the research is undertaken and whether interventions should be deployed have to be led by (not just involve) those who will otherwise be most affected by climate change.

One possible way forward is to establish research centres in the global south. Exchange between centres could be co-hosted by an inter-governmental body such as the UN’s environment programme UNEP, together with civil society and academia. Something similar happened during the Green Revolution in the 1950s and 1960s when new agricultural technologies spread worldwide, and can be seen in humanitarian situations today.

Regional bodies, such as the African Union and the Association of Southeast Asian Nations, could get involved, though the question of who will actually deploy these technologies – which country’s navy or air force will spray the particles – should be decided by international agreement. Nations most affected by the effects of climate change (and least able to adapt) should play leadership roles in not just steering the research but overseeing who, how and when any deployment is made.

Energy Voices is a democratic space presenting the thoughts and opinions of leading Energy & Sustainability writers, their opinions do not necessarily represent those of illuminem.

Any plans to dim the Sun and cool the Earth must be led by those most affected by climate change

The need for deep and rapid emissions reduction, a major issue for COP26, is unarguable. However, the climate has already changed and the evidence is now incontrovertible that emissions reductions alone cannot be sufficient to stay within the 1.5°C limit. Additional actions, such as greenhouse gas removal (GGR) and solar radiation management (SRM) that reverse the trends of climate change, are needed. Some have voiced concerns that GGR and SRM, sometimes referred to collectively as ‘geoengineering’, might lead to reduced efforts on emissions reduction.

Robert Chris

The IPCC Sixth Assessment Report (AR6) [1] shows human activity warming the climate at a rate unprecedented at least in the last 2,000 years. Each of the last four decades has been successively warmer than any prior decade since 1850, and since 2011, average temperature rise is 1.6°C and 0.9°C over land and ocean respectively. Human-induced climate change is recognised ‘with high confidence’ as the main cause of the now routine extreme weather events on every continent. Even under low emissions scenarios delivering the target limit of 1.5°C average global warming will be demanding and temperatures may continue rising into the next century. Within the next fifty years sea level is expected to rise about 2 metres if current emissions levels continue. These changes are being driven by radical and rapid increases of the three most important greenhouse gases (GHGs) in our atmosphere. Carbon dioxide (CO2) concentration is at its highest for two million years, with methane (CH4) and nitrous oxide (N2O) at an 800,000 year high. Averting irreversible instabilities in multiple ecosystems and their potentially disastrous effects on humanity requires that the levels of these GHGs be significantly reduced. 

The need for deep and rapid emissions reduction, a major issue for COP26, is unarguable. However, the climate has already changed and the evidence is now incontrovertible that emissions reductions alone cannot be sufficient to stay within the 1.5°C limit. Additional actions, such as greenhouse gas removal (GGR) and solar radiation management (SRM) that reverse the trends of climate change, are needed. Some have voiced concerns that GGR and SRM, sometimes referred to collectively as ‘geoengineering’, might lead to reduced efforts on emissions reduction. This is referred to as the ‘Moral Hazard’, a term originating in the insurance sector, but latterly applied to a wide range of behaviours where people act more riskily because, if things turn out badly, the negative consequences are borne by others [2]. 

Moral hazard became a concern in relation to climate change because fossil fuel producers argued for policymakers to reduce focus on emissions reduction, and instead to shift to hi-tech GGR and SRM approaches (industrial carbon-capture, mirrors in the sky, sulphuric acid in the atmosphere, for example) [3–6]. However, there is limited evidence of moral hazard in other actor categories. Several studies have indicated a possible ‘galvanizing’ effect. Participants were generally cautious or hostile towards interventions described as geoengineering, but thought they would be more motivated to reduce their personal carbon footprint if they saw government and industry investing in such research or deployment [7–9]. 

Regardless of progress on emissions reduction many effects of climate change are now locked in. Even the most aggressive emissions reduction scenario considered in AR6 is insufficient on its own to avoid exceeding 1.5°C. Therefore, the unequivocal upshot is that significant SRM and GGR interventions are necessary. 

There is an urgent need to extend the scope of existing research on different approaches to GGR and SRM to determine what could safely and beneficially be deployed at scale. SRM techniques, in particular, need careful evaluation for benefits and for any deleterious effects; further studies are essential. There are promising strategies that appear scalable and acceptable. These include cloud brightening over the Arctic ocean to rebuild the increasingly diminished albedo effect from the loss of summer Arctic ice; an example of positive feedback caused by temperature rises in the Arctic Circle being three times higher than the global average. Broad public engagement is also necessary to determine what constitutes 'acceptable’. 

Without appropriate timely research, there is a risk that accelerating climate change, and its unpredictable consequences, will lead to techniques being deployed later, at scale, with a ‘hope for the best’ approach. This would be a high-risk strategy to be avoided. From this perspective, Moral Hazard based claims that research on GGR or SRM should not be undertaken for fear of reducing efforts to abate emissions, become a Moral Hazard in themselves; they have the unintended effect of increasing the risks from climate change for present and future generations. If this is the case, rather than downgrading such research for fear of a Moral Hazard impact on emissions reductions, it should be regarded as a Moral Duty, where every available option is explored to avert things turning out badly, with the negative consequences to be borne by others.

. Energy Voices is a democratic space presenting the thoughts and opinions of leading Energy & Sustainability writers, their opinions do not necessarily represent those of illuminem.

The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. (2021)

Baker, T. On the genealogy of moral hazard. Tex. L. Rev. 75, 237 (1996)

Gunderson, R., Stuart, D. & Petersen, B. The fossil fuel industry’s framing of carbon capture and storage: Faith in innovation, value instrumentalization, and status quo maintenance. Journal of Cleaner Production 252, 119767 (2020)

4. Lane, L. & Bickel, J. E. Solar radiation management: An evolving climate policy option. 

http://www.aei.org/wp-content/uploads/2013/05/-solar-radiation-management-an-evolvingclimate-policy-option_160647160470.pdf

McCright, A. M. & Dunlap, R. E. Anti-reflexivity The American Conservative Movement’s Success in Undermining Climate Science and Policy. Theory Culture Society 27, 100–133 (2010)

6. Simonsen, S. Will These Massive Geoengineering Projects Fix the Earth—or Break It? Singularity Hub 

https://singularityhub.com/2019/02/03/will-these-massive-geoengineering-projects-fix-theearth-or-break-it-more/

Corner, A. & Pidgeon, N. Geoengineering, climate change scepticism and the ‘moral hazard’ argument: an experimental study of UK public perceptions. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, 20140063

Mahajan, A., Tingley, D. & Wagner, G. Fast, cheap, and imperfect? US public opinion about solar geoengineering. Environmental Politics 28, 523–543 (2019)

Merk, C., Pönitzsch, G. & Rehdanz, K. Do climate engineering experts display moral-hazard behaviour? Climate Policy 0, 1–13 (2018)

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Shaun Fitzgerald

Shaun Fitzgerald

Moral Hazard or Moral Duty? - Repairing the Climate with Greenhouse Gas Removal and Solar Radiation Management

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