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As sea ice levels in the Arctic reach their second-lowest levels on record this year and global temperatures continue to rise, a team of California engineers believes they may have a solution to slow further warming of the Earth’s atmosphere. They wanted to make the ice whiter by covering it with glass.
It is the latest development in a series of large-scale climate manipulation proposals known as solar geoengineering. The idea is that we can offset some of the warming caused by heat-trapping greenhouse gases by reducing the amount of sunlight that adds heat to the planet.
One of the most famous ideas is to scatter aerosol particles in the upper atmosphere to reflect some of the sunlight back into space. This idea was studied by David Keith, a Canadian researcher at Harvard University. But there are many other, more exotic proposals. A few years ago, I interviewed a researcher who proposed placing a series of giant sunshades in the space between the Earth and the Sun to reduce incoming solar radiation.
The last entry in this category is from engineers working on the Arctic Ice Project. A recent BBC report described how they were testing a method involving small glass beads that could be scattered in large quantities across Arctic ice to make it more reflective.
The ice at the top (and bottom) of the world is great at reflecting sunlight back into space and keeping our planet cool. But as climate change causes temperatures to rise, the amount of Arctic ice is shrinking in the summer, exposing much of the sun-absorbing black water. This creates higher temperatures, melting more ice and exposing more seawater, creating a vicious circle known as a “feedback loop.” Loss of ice due to warming leads to even more warming.
When Arctic sea ice reached its summer minimum this year, the Arctic Ocean was 2.5 million square kilometers smaller than the average in the 1980s and 1990s.
Researchers at the Arctic Ice Project hope to reverse this trend and protect and even restore Arctic sea ice by making it more reflective. They’ll do this by spreading tiny beads of super-reflective silica (the same material as beach sand) across the ice.
In a 2018 paper, the researchers laid out their plans. Their experiments on frozen lakes in the US and Canada showed that the glass beads stuck to the ice and acted as sunlight reflectors, similar to the glass beads embedded in road signs, reflecting headlight beams back to the driver at night.
They suggest that glazing large areas of ice off the coast of Greenland could have a significant impact on ice protection.
They also assessed some potential risks, including some limited testing of the toxicity of sand glass particles to fish and birds.
But more research is actually needed to understand the true risks of such a proposal for things like marine microorganisms. This will be a large-scale multi-billion dollar project that countries around the world will have to agree on and finance.
All of these geoengineering methods manipulate global systems, so they carry potential risks on a global scale. Some recommendations for reducing solar radiation can reduce plant photosynthesis, which affects crop growth. Weather patterns can be affected because artificial cooling in one area of ​​the atmosphere can change precipitation patterns or prevailing winds in other places.
Scientists who study geoengineering agree that it is not a solution to climate change, but rather a temporary plan to slow or prevent catastrophic damage in the short term. This could buy us some time to transition to clean energy production to reduce carbon emissions.
Despite ambitious statements from world leaders at the 1992 Rio Earth Summit, the 2005 Kyoto Protocol, the 2009 Copenhagen Summit and most recently the 2016 Paris Agreement, global carbon emissions continue to rise. Excess carbon dioxide will remain in the atmosphere, affecting our climate for centuries.
Such radical concepts can have short-term effects, such as using buckets to keep a leaking boat afloat. It works for a while, but even proponents of these projects say the loophole will have to be closed over time.
Bob McDonald is the host of Quirks & Quarks, CBC Radio’s award-winning weekly science program. He is also a science commentator for CBC News Network and CBC’s The Nation. He received 12 honorary degrees and was awarded the Order of Canada.
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