In a never-before-tested plan to alter the Earth’s atmosphere and global temperatures, one of the world’s wealthiest people, Bill Gates, is planning to spend millions with other private donors, to spray the stratosphere with chalk to combat climate change. The chalk would be calcium carbonate, the same material that is the primary component of egg shells, snail shells, seashells, and pearls. Gates and other project backers hope this plan will deflect some of the sun’s radiation from reaching the Earth’s surface, resulting in less-warm conditions here.
Before spraying tens of millions of pounds into the atmosphere, Gates is planning a small scale test in June over the Swedish town of Kiruna. A large test balloon will lift there, bringing 2 kg of chalk and 600 kg of scientific equipment 12 miles up above the Earth’s surface. Once it reaches its target altitude in the stratosphere, it will release the chalk in a plume that should end up being a mile or two long. During this test, scientists tied to Gate’s experiment at Harvard University will measure what impact, if any, the plume has on solar radiation attempting to reach the surface; they’ll also study how the chalk dust particles react with the air at such a high altitude. This data would be used for computer-modeled simulations of much grander planned dispersions.
Other private donors have joined Gates to fund the test.
Some scientists are concerned such a test could backfire. The stratosphere is also the home of the ozone layer which protects Earth from harmful radiation from the earth. It is possible the chalk could interfere with the ozone, allowing harmful radiation which could cause cancer and other health concerns to reach the surface.
The University of Cambridge’s Sir David King, who has served as a chief scientific advisor to the UK Government in the past, told a reporter at The Times that such an endeavor should not be pursued, saying this could be disastrous for weather systems in ways nobody can predict.
Frank Keutsch, Principal Investigator of ScoPEx (Stratospheric COntrolled Perturbation Experiment) and Stonington Professor of Engineering and Atmospheric Science, Harvard John A. Paulson School of Engineering and Applied Sciences, Department of Chemistry and Chemical Biology and Department of Earth and Planetary Sciences said, ” We understand that there are complex societal and governance issues surrounding solar geoengineering and SCoPEx. It’s why we have taken extraordinary steps to try to perform the experiment in a manner that exemplifies good governance, implementing an unprecedented level of transparency and recruiting a highly qualified, independent, external committee to provide advice that we have and will continue to take very seriously. We all realize this is a great learning process, so we and the Committee are doing everything possible to make sure there are opportunities for people to provide comments and constructive criticism. Such input will help the Committee be in the best position possible to weigh whether or not we should proceed with the experiment.”
Ultimately, SCoPEx is a scientific experiment to advance understanding of stratospheric aerosols that could be relevant to solar geoengineering. It aims to improve the fidelity of computer-modeled simulations of solar geoengineering by providing modelers with experimental results vital to addressing specific science questions. Real-life experiments, such as the one Bill Gates is funding through SCoPEx, aim to make quantitative measurements of the aspects of the aerosol microphysics and atmospheric chemistry that are currently highly uncertain in the computer-modeled simulations.
If results of this test are satisfactory, Gates could invest in an exponentially larger deployment where they would spray millions of pounds of chalk over an area of potentially thousands of square miles. The theory is the chalk plume would create a massive sun-shade, blocking light and heat from reaching large portions of land and ocean.
Beyond funding this program, Gates is exploring other measures to take change global climate and weather. In recent weeks, he has discussed ideas to get people and nations to invest only in synthetic meat and new ways of creating materials used for buildings, as two examples. He also wants the world to eliminate all greenhouse gas emissions by 2050.