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Thursday, 31 October 2019

Cover Arctic sea ice with silica microspheres to stop melting ice

One of the direct consequences of global warming is the rapid and massive melting of Arctic ice. However, these icy expanses play an essential role on Earth: they reflect a part of the solar light received in space, thus allowing to regulate the planetary heat. However, with the increasing increase in atmospheric greenhouse gas emissions, temperatures are rising, leading to an ever-increasing melting of ice, which can less and less return sunlight, and a vicious circle thus sets in. To address this, the Ice911 International Association is proposing to cover key areas of the Arctic with silica microspheres, which would act as solar reflectors.

The Arctic is melting at unprecedented speed: Greenland ice is disappearing six times faster than four decades ago. In August, the ice cap lost 60 billion tonnes in just five days of summer thaw. Over the last four decades, 75% of Arctic ice volume has been lost. The current extent of pack ice is the second lowest since scientists began to monitor developments in 1979.

In addition to raising the sea level, this melting contributes significantly to climate change, as Arctic ice reflects sunlight in space. Therefore, less ice means less heat removed from the planet, resulting in an ever greater melting.

Cover the Arctic with silica microspheres to reflect sunlight

Ice911, a non-profit association, offers a potential solution to this threatening feedback loop: the group proposed to cover key parts of the Arctic with millions of hollow glass microspheres to form a protective layer that would reflect sunlight and isolate the ice. " We are a creative species and we need to slow down climate change, " says Leslie Field, founder of Ice911.

The small spheres developed by Ice911 are more like grains of sand than pearls. They are made from silica, a compound of silicon and oxygen, because this material is abundant in the world and harmless for humans and animals. In a sense, the material looks a lot like snow. Reflective beads adhere to ice and water on contact and their chemical composition allows them to avoid attracting oil-based pollutants.

Silica microspheres developed by Ice911. Credits: Susan Kramer / Ice 911

The Ice911 simulations suggest that using technology to restore ice reflectivity could help lower temperatures by 1.5 ° C over much of the northern Arctic. But so far, the technology is still in the field test phase. Field reports that Ice911 started with a very small experience on the terrace of his own home, then conducted small tests in a lake in the Sierra Nevada Mountains and in a Minnesota pond.

Stop the disappearance of pack ice in just three years

In the past two years, Field and his colleagues have brought microspheres into the Arctic, where they have been spread on a frozen lake near Utqia Utvik (Barrow), Alaska. The results, some of which were reported in a May 2018 study , suggest that silica beads did increase reflectivity and ice thickness.

Field does not want to cover the 1.6 million square kilometers of Arctic sea ice with logs. Instead, his team uses climate models to identify strategic areas of the Arctic where microspheres could have maximum impact. One of these areas is the Fram Strait between Greenland and Svalbard. This region is warming almost four times faster than the global average.

Ice911 tested its silica microspheres on localized ice extent in Alaska. Credits: Susan Kramer / Ice 911

Field thinks that in three years, Ice911's technology could be used to stop the disappearance of the pack ice. But she estimates that the dispersion of microspheres would cost about 5 billion US dollars. " When you look at this cost, it's huge. But the cost of doing nothing is far higher . " For the moment, Ice911 still needs to perform more tests and obtain the necessary approvals from governments and environmental groups before considering a large-scale deployment.

Melting arctic ice: an alarming climate
Every September, the Arctic sea ice reaches its minimum extent. Since the 1980s, this minimum has decreased by about 13% per decade and the decline is accelerating. In 1979, the Arctic sea ice covered about 7 million square kilometers. Last month, its extent had dropped to 4.3 million square kilometers.

According to NASA data, this year is tied with 2007 for the second lowest ice extent ever recorded. The worst year was 2012, when ice fell to less than 2.6 million square kilometers. Researchers at the European Space Agency warned that the current rate of carbon emissions meant we could see an ice-free Arctic in only a few decades.

This video shows the evolution of the Arctic pack ice from 1979 to 2016:

Field describes the polar ice as the Earth's heat shield. The oldest and thickest sea ice in the Arctic plays the most important role in the reflection of sunlight, but it is also the one that thaws the fastest. About 95% of this shiny sea ice, which is several years old, has disappeared in 2018. Many methods have been developed to stem the steady flow of heat.

A method only intended to restore Arctic sea ice 

Geoengineering strategies range from developing facilities that suck carbon dioxide from the air into the deliberate injection of reflective chemicals into the atmosphere to return more sunlight into space. Field and her team described Ice911's technology as reversible and localized geoengineering in their 2018 article, but pointed out that spheres are different from what is now called geoengineering.

Instead, Ice911's microspheres "are working to rebuild something that until recently was already there, not driving the climate on a new path ". In addition, because pearls are made from a material that is ubiquitous in the environment, Field explains that she sees a defensible distinction between her organization's approach and efforts to, for example, inject chemicals into the environment. 'atmosphere.

An article in Nature in 2018 reported that the geoengineering of Arctic and Antarctic glaciers could save us crucial time to combat climate change. But Field quickly noticed that Ice911's work should not be considered a sufficient solution in itself. " I do not want this to be an excuse for the coal mines, I do not want people to say," We have nothing to change, the engineers will fix it, "  she says.


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