Solar Radiation Modification: Why this 'science-fiction' climate hack was rejected at UNEA 6
President William Ruto (second left) with (from left) President of UN General Assembly Dennis Francis, Unep Executive Director Inger Anderson and UNEA President Leila Benali at Unep headquaters in Nairobi on February 29, 2024 during the sixth session of the United Nations Environment Assembly (UNEA-6).
What you need to know:
- It is currently unclear whether countries will adopt this technology in the future after the withdrawal at UNEA 6.
- However, if adopted, the estimated cost of implementation would be between USD 2 billion and USD 10 billion annually.
During the sixth session of the United Nations Environment Assembly (UNEA 6), a resolution was proposed on Solar Radiation Modification (SRM), also known as solar geoengineering.
The resolution aimed to combat global warming, and the United Nations Environment Program (UNEP) Executive Director, Ms Inger Andersen, hoped it would be passed.
However, the resolution was withdrawn on the final day, causing disappointment for those who supported it and a victory for those who opposed it.
This resolution was proposed by Switzerland, and some of the countries that rejected it were Somalia, Gabon, Djibouti, Ethiopia, and Botswana.
Explaining to the Nation on what led to the withdrawal, Dr Mfoniso Antia, Programmes Manager for Health of Mother Earth Foundation, Nigeria, who was in Nairobi for UNEA 6 says that most of the things that were proposed by proponents of Solar Radiation Modification are speculative, untested and unproven.
“We are here battling the effect of greenhouse gases in the atmosphere which is majorly from activities from fossil industries, yet some people are now proposing that we start to spray another pollutant; sulfur dioxide just to block the sunlight,” she says.
She tells us that initially, Senegal had backed the proposal from Switzerland and it was a scare, Africa couldn’t afford to be divided.
This is even as a decision from the African Ministerial Conference on the Environment (AMCEN), that was held in August last year proposed that there should be a precaution on Solar Radiation Modification use.
“It was a big fight to get all the African groups together and convince them why it should be rejected. With more knowledge and exposure from civil societies, a country like Senegal saw the need to drop their proposal,” says Antia.
This UNEA has taught us that African leadership is working, and cannot be cajoled. We now know that Africa can take a stand and stick to it, it was a shock to the world,” she adds.
She explains that research done so far by bodies like the human rights council of the London Protocol and Convention prove that the impacts far outweigh whatever it is that is perceived as a solution.
But what really is this technology?
In the 1960s, scientists started studying a set of methods and technologies aimed at deliberately changing the climate system to reduce the impact of climate change. This set of methods is known as geoengineering.
According to the Intergovernmental Panel on Climate Change (IPCC), geoengineering includes many approaches.
One such approach is solar geoengineering, which involves reflecting the sun's rays back into space to prevent them from reaching the earth, causing a cooling effect.
Researchers have identified three ways in which this can be done. A recent study showed that this technology can help cool the planet for about 100 years. But after that, the cooling effect starts to fade.
A study published in the scientific journal Proceedings of the Royal Society explains that solar geoengineering mimics the cooling effect of large volcanic eruptions, whose residual atmospheric ash particles and sulphuric acid droplets scatter and refract some incoming sunlight. In other words, when a volcano erupts, the earth cools.
A diagram from the Royal Society journal showing how geoengineering works.
The SRM technology allows scientists to artificially mimic this volcano effect by shooting sulfur dioxide – a colourless gas that smells like a rotten egg, into space.
This is done by using planes or specific types of balloons. This article explains that sulfur dioxide cools the earth by converting it into sulphuric acid particles that, in turn, block incoming solar radiation, leading to global cooling.
It is currently unclear whether countries will adopt this technology in the future after the withdrawal at UNEA 6.
However, according to a study published in the Royal Society Journal, if it is adopted, the estimated cost of implementation would be between USD 2 billion and USD 10 billion annually.
The other form of solar radiation modification that scientists have proposed is to increase the albedo (the amount of sunlight that bounces, or reflects, off of the Earth) for the dark clouds called stratocumulus.
"Clouds composed of a greater number of smaller water droplets are brighter; they could be brightened by introducing more cloud condensation nuclei into the lower atmosphere. If seawater were sprayed upwards as a fine mist, then after its evaporation, some salt particles would stay suspended," explains the Royal Society Journal.
The third way, cheaper than the first two, is to change the earth's radiative balance by increasing outgoing long-wave radiation.
"In general, clouds reflect some incoming shortwave radiation and trap some outgoing long-wave radiation. High altitude cirrus clouds are believed to have a net warming effect," says the study.
While no country has passed legislation on solar geoengineering, some countries are actively conducting studies to prove that it works.
Between 2017 and 2018, for instance, research on this subject received about USD 8 million, less than what is spent on research for climate change.
Reacting to the withdrawal of the resolution, Ms Andersen said that the nature of multilateral environment agreements is to ensure everyone is onboarded and, therefore, having a global conversation before damage is done is essential. She said that there needs to be a deeper understanding of the technology.
"Many countries and people may not have fully internalized this complex technology. It made it clear that our role as UNEP is to keep our eyes on the horizon, see what new waves may be hitting our environmental shores, and assess their impact before we have a global conversation on deployment," said Ms Andersen.
However, there are existing risks to solar radiation modification, which is why some delegates who were not for it put it on hold.
A study published in the journal Earth Systems Dynamics shows that one of the significant risks could occur when technology suddenly stops being used, and the atmosphere adjusts to what it was like previously.
"We would be forcing our children and their descendants to maintain a technological regime that, if suddenly stopped, could be an existential threat to the planet," said lead author Susanne Baur, a climate modelling expert.
A study published in the Nature journal suggests that solar geoengineering could result in the re-emergence of malaria in developing countries.
"Our simulations indicate that proposed geoengineering schemes could lead to local benefits in East Africa and large adverse impacts on West Africa and southern Asia. Totalled across regions, the geoengineering scenarios we examined have at best a neutral but patchwork effect on total malaria risk, and at worst could elevate malaria risk relative to climate change without geoengineering," shows the study.
It also impacts our biodiversity, which is already at risk even in current scenarios.
"Compared to a moderate climate change scenario, rapid geoengineering implementation reduces temperature velocities towards zero in terrestrial biodiversity hotspots," explains a 2018 Nature study.
It is important to note that this technology is not a substitute for reducing greenhouse gas emissions, but it can only help lessen atmospheric carbon burden.
