Solar geoengineering may revert climate changes, but its side effects are unknown; Harvard University wants to start experiment in 2018

It may sound like science fiction, but the idea came up at Harvard University and is supported by 12 renowned scientists all over the world, including Brazilian physicist Paulo Artaxo. Some of the greatest climate change specialists consider creating a “giant sunshade”, made of gases and particles carefully positioned around the globe, to minimize damages caused by global warming.

The solar geoengineering technique is, essentially, the injection of aerosol particles into the stratosphere to reflect away a little inbound sunlight. It is estimated that results might come quickly: the global warming process can be stopped in two years and reverted to 35.6ºF, according to optimistic theses. However, its side effects are still unknown.

The international group of scientists behind the idea published an article on Nature magazine, taking a stand on studies that would make the technique viable. “Geoengineering is being discussed as a way to cool the planet, fast. The technique is outlandish and unsettling. It invokes technologies that are redolent of science fiction — jets lacing the stratosphere with sunlight-blocking particles, and fleets of ships spraying seawater into low-lying clouds to make them whiter and brighter to reflect sunlight,’ says the group.

“The technique is controversial, and rightly so. Yet, if such approaches could come through technically and politically, they could slow, stop or even reverse the rise in global temperatures,” one scientist affirms.

Project started in Harvard

A study group at Harvard University has been working on environmental chemistry and ozone layer for 40 years and led the Stratospheric Controlled Perturbation Experiment (SCoPEx). The project is estimated in US$ 20 million and is supposed to be launched on the second half of 2018. According to the official website, it is not a viability test, but an experiment that simulates the giant sunshade effects and assess the security of its use.

At the heart of SCoPEx is a propelled scientific balloon that will be sent to the stratosphere, 20 kilometers away from the Earth’s surface, and scientists will be able to create some small air volume in which we can add gasses or particles to be sent. This compound can be observed for over 24 hours. Sensors installed on the equipment will be capable of measuring the properties of modified air and send them to computers to be analyzed at Harvard.

Two rounds of experiments involving water and sodium carbonate particles are expected by 2022. There is also the possibility of new experiments with aluminum oxide and even diamonds. “It is not the only nor the first academic study on that matter, but it certainly is the biggest and most comprehensive one”, says Gernot Wagner, co-founder of the project, in an interview to the British newspaper The Guardian.

Geoengineering can be the solution for poor nations

According to the article on Nature, the developing nations are the most vulnerable to climate change, mainly those located in the South of the globe. The Intergovernmental Panel on Climate Change (IPCC) is forecasting rising seas eroding small island states, declining food production in many regions of Asia, water stress across Africa and major loss of biodiversity in South America.

The 12 signatories of the text, coming from Bangladesh, Brazil, China, Ethiopia, India, Jamaica and Thailand, invite these nations to encourage discussions about modeling, ethics and governance of solar geoengineering projects.

“It is too early to know what its effects would be: it could be very helpful or very harmful. Developing countries have the most to gain or lose. In our view, they must maintain their climate leadership and play a central part in the research and discussions around solar geoengineering”, they say in the article.

The non-governmental organization Solar Radiation Management Governance Initiative (SRMGI) has created a program that funds research projects in up to US$ 400 thousand for developing solar geoengineering in developing countries.

Nevertheless, the main proponents of this technique emphasize that any attempted solution with geoengineering must be a complement to an aggressive policy on emission reduction – not a replacement.

“It [giant sunshade] would only mask the warming effect of greenhouse gases. Ocean acidification would still pose a threat to marine life if carbon-dioxide emissions were not slashed. Sulfur dioxide might delay ozone regeneration in the stratosphere. And whichever aerosol was used to filter out sunlight, more research would be needed to measure impacts on health and the environment”, the scientists affirm.

Content published in July 27, 2018

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