Billionaire businessman Bill Gates is making investments to financially support the development of a sun-obscuring technology that would conditionally reflect sunlight away from the Earth’s atmosphere, creating a global cooling effect. The Stratospheric Controlled Perturbation Experiment (SCoPEx), issued by scientists at Harvard University, aims to analyze this solution by spraying non-toxic calcium carbonate (CaCO 3) powder into the Earth’s atmosphere.
The study on the effectiveness of solar geoengineering was stopped for years due to controversy. Opponents think such science carries unpredictable risks, including extreme changes in weather patterns not unlike the warming trends we’re already experiencing. Likewise, environmentalists fear that an overblown change in mitigation strategy will be treated as a green light to continue emitting greenhouse gases with little or no change in current consumption and production patterns.
SCoPEx will initially take a small step in its research in June, near the city of Kiruna, Sweden, where the Swedish Space Corporation has agreed to support the launch of a balloon that will carry a scientific team 20 km high. The launch will not release any stratospheric aerosols. Rather, it will function as a test to maneuver the globe and analyze communications and operating systems. If successful, this could be a step toward a second experimental stage that would release a small amount of CaCO 3 dust into Earth’s atmosphere.
Harvard University professor of applied physics and public policy David Keith distinguishes the “lots of real concerns” about geoengineering. It is true that no one knows what will happen until CaCO 3 is released and then studied. Keith and his fellow SCoPEx scientists published a paper in 2017 saying the dust could actually replenish the ozone layer by reacting with ozone-destroying molecules.
“Further research on this and similar methods could lead to reductions in risks and greater efficacy of solar geoengineering methods,” the paper’s authors write.
The exact amount of CaCO 3 needed to cool the planet is unknown, and SCoPEx scientists can’t confirm if it’s the right stratospheric aerosol for the job. Initial research suggests the substance has “near ideal optical properties” that would allow it to absorb much less radiation than sulfate aerosols, causing significantly less stratospheric heating.
This is the purpose of the experiment: once a certain safe and experimental amount of CaCO 3 is released, the balloon will fly through it, sampling the atmospheric reactions and recording the dynamics produced. Frank Keutsch, the project’s principal investigator, doesn’t know what the results might bring. The aerosol wouldn’t immediately alter stratospheric chemistry at all: “All it would do is scatter maximum sunlight and thus cool the planet.”
Proponents of geoengineering cited the global cooling effects of volcanic eruptions resulting from the introduction of sulfuric ash into the atmosphere. The eruption of Mount Tambora in Indonesia in 1815 resulted in the “year without a summer”, while the eruption of Mount Pinatubo in the Philippines in 1991 lowered the global average temperature by 0.5°C.
The deliberate introduction of similar particles could offset decades of greenhouse gas emissions. A report by the Intergovernmental Panel on Climate Change suggested that the SCoPEx procedure could lower global temperatures by 1.5°C for no more than US$1-10 billion a year.
These drops in temperature bring with them serious risks. Freezing temperatures in 1815 led to crop failures in near-famine conditions. British scientists cited stratospheric aerosols from volcanic eruptions in Alaska and Mexico as the potential cause of drought in Africa’s Sahel region.
A major global climate disruption could have unintended effects, negatively impacting highly populated regions and triggering another refugee crisis.
David Keith proposed the creation of a “risk pool” to compensate smaller nations for the collateral damage done by such tests, but such payment might be of little comfort to those displaced by uninhabitable conditions. The United States, Brazil and Saudi Arabia blocked a 2019 United Nations assessment of global geoengineering plans. International cooperation will be required to assess the risks, the winners, and the losers of any such experiment, and how best to proceed taking everything into account.
OCDE members should continue their efforts, bearing in mind the unknown risks associated with solar geoengineering, to develop economically attractive renewable energy technology, even while complementing those efforts with limited and careful research and experimentation. Posted by Iraic.info, a news and information agency.