Science

Cooling The Earth By Blocking Sunlight Is Relatively Simple — But Should We?

The risks of solar geoengineering will be magnified if critics are ignored and researchers are allowed to self-regulate.

by Albert Van Wijngaarden, Adrian Hindes, Chloe Colomer and The Conversation
Muratart / shutterstock

Solar geoengineering research is advancing fast after a recent flurry of funding announcements. Yet these technologies are still speculative and have many critics, and we worry their concerns won’t be heard. If geoengineering is essentially allowed to self-regulate, with no effective global governance, future research could easily take us down a dangerous path.

Solar geoengineering refers to proposals to reduce global warming by reflecting a portion of sunlight back into space before it reaches the Earth’s surface. In its best-known form, this means using high-flying aircraft to inject tiny reflective particles into the upper atmosphere.

This so-called “stratospheric aerosol injection” hasn’t actually happened yet, beyond a few very small experiments with balloons. Yet for a long time, such ideas remained fringe and too controversial to even consider — and for some academics, they still are.

The academic discussion was highly polarized from the start. Opponents, mainly governance scholars and social scientists, stood firmly entrenched against assumed proponents, mainly natural scientists and engineers. Both sides had their champions, arguments, assumptions, key publications, and meetings, generally working on the topic without proper engagement with the other side.

This polarization is still visible in publishing today. Take, for example, articles on The Conversation. Critics focus on potential negatives such as altered rainfall patterns, the infringement of human rights, or even a catastrophic “termination shock”. Advocates highlight potential benefits such as reducing extreme heat and preserving ice caps, while others suggest we may soon be forced to try it.

The authors of these articles are all academic experts. Yet, they come from different disciplines and use different arguments.

A public and private funding boom

Though the two camps have not resolved their arguments, geoengineering research funding is suddenly booming. There are major philanthropic pledges of US$50 million (£38 million) and US$30 million from the Simons and Quadrature Climate foundations, which are vying for the title of biggest donor with the £10.5 million and £56.8 million of the UK government’s UKRI and Advanced Research and Innovation Agency programs.

The 1991 eruption of Mount Pinatubo in the Philippines blocked so much sunlight the world temporarily cooled by a few tenths of a degree. Solar geoengineering works on a similar principle.

Dave Harlow / USGS

Other key organizations that are speaking about the need for more research include the European Commission, the US government, and the World Climate Research Programme. This comes on top of the shock of controversial private enterprises pushing for solar geoengineering, most notoriously the US-based start-up Make Sunsets.

Support is certainly not unanimous. Many prominent scholars have signed up to a call for a moratorium, for instance. At a recent UN Environment Assembly session in Kenya, many climate-vulnerable nations mobilized against calls for further research into what they see as a highly risky technology that would enable big emitters to carry on emitting.

However, many powerful interests are seemingly in favor of more research, while the 1.5°C global warming target is moving ever further out of sight. In the near future, we can, therefore, expect further research, perhaps including including small-scale outdoor experiments.

As PhD students working on geoengineering, situated somewhere between both camps, we have found this polarisation deeply unproductive and difficult to deal with. Our own research sometimes feels like wandering through a minefield of opinions and perspectives. Yet, we can also see the valuable concerns and hopes of both sides.

One proposal involved releasing particles from a tethered high-altitude balloon.

Hugh Hunt

That’s why we believe that upcoming research projects must factor in the concerns of opponents and not represent only supporters of geoengineering or those who have not been explicitly against it. For one thing, excluding critical voices would directly impact the scientific process.

However, this exclusion is especially worrying as there are currently no governance structures for solar geoengineering. If efforts to develop such governance only involve supportive researchers, they could lack the critical capacity to prevent risks or undesired effects. Disasters in the financial sector and the chemical industry warn us of the perils of self-regulation without critical voices.

Learn from the critics

There are other critiques that ought to be factored into any major research project. They include concerns that simply researching the technology will create a slippery slope towards it being deployed or worries that geoengineering ignores the social and political dynamics behind climate change and addresses only its outcomes. There are also major governance concerns over issues such as the role of the military (could geoengineering be deployed for security reasons in contested regions like the Arctic?) or the concentration of research at influential institutions in the US and Europe.

Over time, geoengineering researchers have become more aware of such arguments, and some are explicitly trying to include them in their work. The American Geophysical Union has recently published an ethical framework for geoengineering, which should provide valuable guidance for any research project. However, without active dialogue with critical scholars, their arguments will likely only echo faintly in the pro-research space.

In practice, more engagement between the two camps would come with many difficulties. For advocates, it can be tempting to avoid such debates and exclude those who disagree with the very foundations on which their research is built. On the flip side, some scholars who have already explicitly argued against the continuation of solar geoengineering research would nevertheless have to participate in it.

The practical implications will, therefore, need to be carefully worked out. However, a more productive dialogue might still shape a future that can be acceptable to all sides.

This article was originally published on The Conversation by Albert Van Wijngaarden at the University of Cambridge, Adrian Hindes at Australian National University, and Chloe Colomer at UCL. Read the original article here.

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