Geoengineering and development – what price on equity and justice in the coming climate culture wars?

Climate geoengineering is a divisive topic. What could be good – the promise of ways to either cool the planet through enhancing the reflection of sunlight, or to remove CO2 from the atmosphere thereby reducing global warming – could also be terrible. Particularly if banking on hypothetical solutions from unproven technology reduces the urgency of efforts to stop putting greenhouse gases into the atmosphere.

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Andrew Norton
Andrew Norton was director of IIED from 2015-2022
20 December 2017
Solar-radiation management aims to reduce the amount of solar energy warming the planet by blocking the sun with tiny particles (Photo: Mike, Creative Commons via Flickr)

Solar-radiation management aims to reduce the amount of solar energy warming the planet by blocking the sun with tiny particles (Photo: Mike, Creative Commons via Flickr)

The debate on geoengineering as a potential approach for addressing climate change has been hotting up over the last year.

This is partly due to the realisation that the impacts of climate change at even 1°C of warming over pre-industrial levels (which is roughly where the world currently is) seem substantial – driven home for many by the wave of extreme weather events the world experienced throughout 2017.  

Increasingly, the supposedly safe limit of 2°C in the Paris Agreement on climate change looks decidedly unsafe. And why wouldn't it be? The average temperature of the earth's surface in pre-industrial times was around 14°C. An increase of 2°C might not sound much, but it represents adding considerably more energy to global weather systems.

That is likely to lead to profound change. Even the more ambitious (and much safer) Paris target of 1.5°C gives cause for concern.

The chances of staying within even 2°C are currently not good. If all of the national climate action plans of all the countries on which the Paris Agreement's hopes of mitigating climate change are based were perfectly executed, then we would still likely be headed for 3°C of warming by 2100.

But perhaps the biggest reason why geoengineering has become increasingly normalised is the fact that one of its branches, carbon dioxide removal (or 'negative emissions technology'), has been baked into technical assumptions about how the world might stay within 2°C.

Does the science suck?

The database of scenarios outlining plausible pathways to staying within 2°C behind the International Panel on Climate Change Fifth Assessment Review illustrates this well. The overwhelming majority of them (95 per cent) rely on negative emissions technology to limit warming to 2°C by 2100. 

Effectively, this means the world overshoots its carbon budget and then sucks a load of the stuff out of the atmosphere afterwards. If this sounds like cheating there are solid grounds to agree with that.

Significantly, the technology is not proven. The UN Environment 'Emissions Gap' report considers bio-energy with carbon capture and storage as the most mature option. This involves growing biomass (plants), transporting it to power stations, burning it to generate energy, and then pumping compressed carbon in near-liquid form underground for storage.

It is basically untested, highly doubtful as an economic proposition (given that similar technology for coal has never proved workable at scale), and even if it did work, would use vast amounts of land. Various propositions exist for what is called 'direct air capture' – pulling carbon out of the air. While they are technically feasible in principle, they are likely to remain prohibitively expensive.

The other branch of geoengineering receiving a lot of public attention involves increasing the reflection of sunlight away from the earth. A US Congressional subcommittee hearing on this topic on 8 November illustrates some of the recent political attention.

The method that is most likely to be feasible involves the use of aerosols (tiny particles) deployed in the stratosphere to mimic the known cooling effects of some historic volcanic explosions. In some cases, these cooling effects have been substantial if shortlived. While serious experimental field testing has not yet been carried out (there are plans), extensive computer modelling and laboratory experiments suggest that this method is likely to be technically and economically feasible.  

It raises all kinds of questions. What happens if sunlight reflection methods are deployed and then stop? Would global temperatures rise at a rate that would make adaptation incredibly difficult?

The risks of unintended consequences would be massive (historically humans have been very bad at predicting our influence on climate systems). Rainfall, temperature and weather patterns would not be static and the interactions unpredictable. Maarten van Aalst and Pablo Suarez raise the spectre of 'predatory geoengineering' – actions taken by one state seeking to control its own climate with a reckless disregard for the impacts on others.

This is not hypothetical – Oliver Morton's book 'The Planet Remade: How Geoengineering Could Change the World' describes a link between volcanic eruptions in the northern hemisphere and instances of drought in the Sahel. The risks are complex and Morton argues that it may be feasible to offset such effects by countering a volcanic release of aerosols in the northern hemisphere with a deliberate one in the southern.

Two key conclusions

None of these technologies discussed here is remotely ready for large scale cost-effective and safe deployment. This is clear for both sunlight reflection methods and negative emissions approaches. And the sunlight reflection methods are not a solution, but a band aid – an interim palliative. Relying on the timely emergence of these technologies is a poor and irresponsible bet.  

Meanwhile, pathways to reduce emissions rapidly enough to stabilise the planet's climate inside of 2°C of warming above pre-industrial levels require year-on-year emissions reductions globally of around 10 per cent in the 2030s. Kevin Anderson and Alice Larkin of the Tyndall Centre argue that assuming this can be done without substantial changes to energy demand, consumption patterns, growth models and lifestyles among rich countries and rich people is not realistic. 

There is no substitute for urgent action on emissions. This is a radical proposition and currently more the territory of social movements than orthodox politics – at least outside of a few highly progressive governments.

Effective known approaches to reducing carbon – such as increasing tree cover – are not currently being deployed at the scale they should be. When this is done through providing community land rights, it can also have positive impacts on poverty reduction, resilience, and local and regional weather.

The second important conclusion is that none of the techno-solutions under consideration will have equitable impacts between rich and poor nations, between powerful and powerless people.

The social justice implications are massive. The bio-energy with carbon capture approach, if deployed at scale, could threaten food production and nutrition – and pose threats to poor communities' ability to retain land and natural resource rights. Sunlight reflection methods are highly uncertain with potentially alarming geopolitical considerations for countries without the power and wealth to be in the driving seat.

We can expect that as concern grows at the gap between where the world needs to be and where it is on climate action that the debate on geoengineering will heat up as a fault line in the coming culture wars on climate change. This needs to be seen as a development issue as well as a climate issue.

It is vital that poor people and poor countries are included in the way such research is regulated and governed. The Least Developed Countries Group has been a powerful voice for global social justice in the climate negotiations. Their voice, among others, could be critical in ensuring that the solutions to tackling climate change do not involve reckless and predatory action by the rich and powerful.

Andrew Norton ( is director of IIED.

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Andrew Norton was director of IIED from 2015-2022

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