Switzerland’s Gorner Glacier above Zermatt has thinned to the point of being detached from its accumulation area. (Julien Seguinot)

The Climate Fight Over Geoengineering and Global Governance

The realms of science and diplomacy have been divided over the pursuit of new technologies that could modify nature and cool the planet – and the potential governance frameworks that could safely guide this kind of research and development. But with the rise in global mean temperatures, the 2023 GESDA Science Breakthrough Radar® anticipates, it has become “increasingly urgent” for the world to decide whether to research and deploy technological fixes known as geoengineering, or solar radiation modification (SRM).

By John Heilprin

September 12, 2024

As global temperature records fall, and as extreme weather is more commonly associated with climate change, the debate within scientific and diplomatic circles over geoengineering is heating up. Eco-regeneration and geoengineering forms one of the Radar’s five scientific platforms, along with quantum revolution and advanced AI, human augmentation, science and diplomacy, and knowledge foundations.

Short-term fixes like SRM are gaining attention as policymakers search for ways to combat climate change, though nearly all of the action in the research field has been in computer modeling; field experiments – a far cry from testing – are rare and extremely limited in scope. Such interventions, which remain mostly in the theoretical realm, are intended to offset the warming effects of carbon pollution by causing Earth to absorb less solar radiation, particularly when most nations are not cutting enough of their emissions of carbon, methane and other gases that trap heat in the atmosphere like a greenhouse.

The most prominent and studied approach, according to the Radar, is stratospheric aerosol injection (SAI), which entails injecting chemicals into the lower stratosphere to reflect back some incoming sunlight – thus reducing the amount of solar radiation that the Earth absorbs. SAI is a specific technique within the broader category of stratospheric aerosol geoengineering (SAG) measures that involve the release of small particulates like sulfates to simulate the cooling from volcanic eruptions.

“When assessing the potential efficacy and risks of SAG, the sensitivity of tropical monsoon precipitation changes should be also considered,” according to a paper published in Oxford Open Climate Change in August by several climate researchers including Govindasamy Bala, a professor of atmospheric and oceanic sciences at the Indian Institute of Science in Bangalore, who served as scientific moderator for the 2023 Radar’s discussion of SRM.

“Despite SAG being considered as one of the more viable SRM options, climate modeling studies have raised concerns about its potential negative impacts on the global and regional hydrology,” they wrote. “SAG could also change the ozone concentration in the stratosphere, affect human health and have ecological impacts. Additionally, significant uncertainties surround the climate response to the factors such as the injection latitude, altitude, and the overall distribution of aerosols.”

Bala tells GESDA News that only “very small scale” experiments have been carried out so far – any real technological applications for SRM are probably at least a decade away – and “if you really look at the experiments, they’re harmless” because so far they’ve only involved sprayed sea salt or small amounts of sulfate. He recommends studying SRM as a last-resort measure to handle a “low probability, high impact” planetary emergency. “I don’t have any opinion about whether the experiments should go ahead or not,” he says. “We are doing only computer modeling. We are doing only simulations right now. It’s harmless.”

Research published earlier this year in Geophysical Research Letters by atmospheric scientist Elia Wunderlin of the Swiss Federal Institute of Technology Zürich and several colleagues found that sulfate particles can cool the climate but also cause “side effects” by heating the tropical lower stratosphere if done with injections at low latitudes. “We found that some detrimental effects of this injection are of a similar magnitude to those from climate change itself in some regions,” they summed up.

 

An illustration of several theoretical methods to cool the Earth (U.S. NASA) 

‘We should consider all options at hand’

Switzerland, backed by other Western nations, brought a resolution before the United Nations Environment Assembly at Nairobi, Kenya, in February, aiming to create the first UN expert panel to look at SRM technologies. Proponents argued the world needs a safe space for discussion and a global repository of options for governments to examine. But opposition from several nations, fearful that any consideration of SRM might weaken efforts to address the root causes of climate change, prompted the resolution to be withdrawn. Switzerland also tried to introduce the resolution in 2019.

The opposition was initially led by African nations, mirroring the African Ministerial Conference on the Environment’s 2023 decision calling “for a global governance mechanism for non-use of solar radiation management.” They were joined by other countries from the Global South. The European Union staked out a middle ground that involved widening the expert panel to make a broader assessment with the buy-in of an intergovernmental process.

UNESCO’s first report on the ethics of climate engineering recently offered recommendations for research and governance along the lines of the Swiss proposal. “In the face of the environmental emergency, we should consider all options at hand, including climate engineering. However, their deployment should not come at the expense of the commitments made under the Paris Agreement, and not without a clearly established ethical framework,” said Gabriela Ramos, UNESCO’s assistant-director general for social and human sciences.

Ready or not, some experiments underway

The U.N.’s panel of top climate scientists, the Intergovernmental Panel on Climate Change, met last year at Interlaken, Switzerland to approve a synthesis of its latest round of reports since the landmark 2015 Paris treaty. In the synthesis, scientists wrote that “SRM approaches, if they were to be implemented, introduce a widespread range of new risks to people and ecosystems, which are not well understood. SRM has the potential to offset warming within one or two decades and ameliorate some climate hazards but would not restore climate to a previous state, and substantial residual or overcompensating climate change would occur at regional and seasonal scales (high confidence).”

The 2023 Radar concludes SRM could fully or partially offset rising temperatures and reduce some of the harmful impacts of anthropogenic climate change. Some options are mainly local, which limits their effectiveness but brings fewer complications. Others, like SAI, would affect the whole planet.

“All SRM approaches raise challenging questions such as who should control the technologies, if and when they should be deployed, and what should happen if a deployment goes wrong or fails entirely,” the Radar says. “Another concern is ‘moral hazard’: the possibility that investing in these SRM approaches would reduce the impetus to cut greenhouse gas emissions.”

At the 2022 GESDA Summit, a panel hotly debated such opportunities. Pascal Lamy, chair of the Climate Overshoot Commission which works to limit global warming to the Paris treaty’s preferred limit of 1.5° Celsius above pre-industrial levels, pointed out that opposition to SRM falls into two main arguments: the belief it is too risky and it will undercut better options. Frank Biermann, a professor of global sustainability governance at Utrecht University, argued that SRM does not address the core problem of lowering carbon emissions. 

Janos Pasztor, a former top UN adviser on climate change who headed a climate governance initiative for the Carnegie Council for Ethics in International Affairs, said SRM should be at least considered proactively, because emissions-cutting alone will not save the day. “Emission reductions and carbon removal is absolutely necessary, number one priority,” he said. “But we know that simply doing those is not enough to keep the temperature below 1.5°C.”

Where the science and diplomacy can take us

The 2023 GESDA Science Breakthrough Radar®, distilling the insights of 1,500 scientists from more than 70 countries, tells us that interventions that alter solar radiation on Earth are controversial because of their relatively cheap costs and huge impacts on the planet at global level. The growing effects of a changing climate make it seem increasingly attractive to trial planet-wide geoengineering experiments. However, the effects of such interventions at local level are poorly understood.

The findings in the 2023 Science Breakthrough Radar®

Based on the Radar, here’s where we stand in several important areas:

3 Eco-Regeneration and Geoengineering