From seeding clouds to clearing them through the recapture of carbon dioxide, geoengineering projects abound in the Asia-Pacific region. They aim to counter the consequences of global warming. But some scientists are worried regarding their long-term effects.
The massive bleaching of corals in the Great Barrier Reef, due to rising global temperatures, has prompted scientists to develop an impressive new defense: recompose clouds to better block the sun’s rays.
Researchers used a turbine mounted on the back of a boat to project plumes of seawater above the ocean’s surface. This spray evaporates and the salt residue rises to low-level clouds, where it promotes the formation of tiny water droplets. The ability of these clouds to reflect shortwave solar radiation [dans l’espace] is reinforced. And it prevents the sun’s rays from reaching the sea of corals below in large quantities and heating it up.
“The reef is being massacred”, this is the clean and flawless explanation given by oceanographer Daniel Harrison, senior lecturer at Southern Cross University. [de Coffs Harbour, en Australie], to explain why he considers it necessary to resort to such an extraordinary process, tested for the first time last year off the northeast coast of Australia.
Artificially transforming the environment
Daniel Harrison is leading field trials of this technique known as “sea cloud lightening”. His work is part of a larger – and controversial – campaign in the Asia-Pacific region to tackle climate change by artificially transforming the environment. This is called geoengineering, which also involves modifying precipitation and removing carbon dioxide from the atmosphere, for example.
There is growing interest in geoengineering in scientific circles and among politicians, alarmed by the state of the environmental situation.
Nonetheless, it continues to leave many researchers and international environmental organizations skeptical, raising the important question: Don’t governments and businesses risk using the mitigation of problems achieved by these new technologies as an excuse to avoid to drastically reduce the emissions responsible for global warming?
Global geoengineering pioneers, however, insist that this might be one of the big solutions to solving the climate crisis.
Mitigate the effects of climate change
The United Nations Intergovernmental Panel on Climate Change (IPCC) defines geoengineering as “A vast set of methods and technologies implemented on a large scale with the aim of deliberately modifying the climate system in order to mitigate the effects of climate change”.
There are often two main categories of techniques: on the one hand, solar radiation management (GRS), which aims to temporarily cool the Earth by sending solar radiation back into space; on the other hand, those of carbon dioxide elimination, which consist in physically sequestering the greenhouse gas present in the atmosphere.
Daniel Harrison’s Great Barrier Reef Cloud Brightening Project is in its early stages, with a small team and a modest budget of around $ 300,000 [266 034 euros] for its first test conducted in 2020. But it has already proven that it is possible to produce seawater droplets in sufficient quantity thanks to this process of manufacturing artificial fog.
Reduce the sun’s radiation
Daniel Harrison’s laboratory is the largest on the planet dedicated to the Great Barrier Reef. It was almost inscribed on the list of World Heritage in Danger by the United Nations at the beginning of 2021, but Australia has managed to avoid this classification – and the responsibilities in terms of protection that result from it – thanks to intense lobbying.
Daniel Harrison explains that the current device would have to be multiplied tenfold (using regarding 3000 nozzles instead of 320) to produce enough particles to clear nearby clouds by regarding 30%. According to models carried out by his team, this would reduce solar radiation hitting the reef by nearly 6.5% over a period of regarding two months during the summer.
To get there, the operation would require the installation of 800 to 1,000 stations to cover the 2,300 kilometers of the Great Barrier Reef, which will take time: ten years for a full test, according to Daniel. Harrison.
Study the consequences of cooling
But his cloud-lightening technique doesn’t convince everyone. Thus, climatologist Masahiro Sugiyama, associate professor at the University of Tokyo, is among those calling for more studies on its effectiveness and possible consequences.
“A one-off cooling of a place causes a change in atmospheric fluxes, and we do not know what the negative effects might be”, he warns.
Despite the skepticism of some, in Asia we are witnessing an increase in demand for cloud engineering projects. The public authorities see it as a potential weapon in the fight once morest forest fires and floods. It might also promote hydroelectric power generation, according to Dwipa Wirawan of the Indonesian National Agency for Research and Innovation (Brin).
Usually, cloud seeding in cold climates involves injecting silver iodide or a similar substance into the atmosphere to mimic ice cores. The clouds thus generate more ice crystals, which then fall as snowflakes or melt into raindrops, in
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Akane OkutsuErwida MauliaApornrath Phoonphongphiphat et Ck Tan
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