To cool planet, re­searchers pro­pose spray­ing par­ti­cles into marine clouds

China Daily (Hong Kong) - - YOUTH -

SAN FRANCISCO — A group of re­searchers at the Univer­sity of Wash­ing­ton is in­ves­ti­gat­ing the idea of marine cloud bright­en­ing as a strat­egy to off­set global warm­ing. As a short-term mea­sure for a pos­si­ble fu­ture emer­gency sit­u­a­tion, the strat­egy in­volves spray­ing salt­wa­ter into clouds above oceans to boost their ca­pac­ity to re­flect sun­light.

In a paper pub­lished in the jour­nal Earth’s Fu­ture, two UW re­searchers, in­clud­ing lead au­thor Rob Wood, a pro­fes­sor of at­mo­spheric sciences, say small-scale tests of marine cloud bright­en­ing would also help an­swer sci­en­tific ques­tions about clouds and aerosols’ pos­si­ble role to help cool the planet.

One of the big­gest un­cer­tain­ties in cli­mate mod­els is the clouds, which re­flect sun­light in un­pre­dictable ways. Wa­ter droplets can only con­dense on air­borne par­ti­cles, such as smoke, salt or hu­man pol­lu­tion. When the air con­tains more par­ti­cles, the same amount of mois­ture can form smaller droplets, which cre­ates whiter, brighter, more re­flec­tive clouds.

For sev­eral years, re­searchers there have been work­ing with a group of engi­neers in the San Francisco Bay Area of North­ern Cal­i­for­nia, on the US West Coast, to de­velop a noz­zle that turns salt­wa­ter into tiny par­ti­cles that could be sprayed high into the marine cloud layer, ac­cord­ing to a news re­lease from UW, lo­cated in the US Pa­cific North­west.

Now wait­ing for fund­ing from govern­ment or pri­vate donors, the re­searchers pro­pose to pro­duce a sprayer that is able to eject tril­lions of aerosol par­ti­cles per se­cond, con­duct ini­tial lab­o­ra­tory tests of the sprayer, do pre­lim­i­nary out­door tests in a fairly flat coastal area rel­a­tively free of air pol­lu­tion and prone to marine clouds, and then move to small-scale off­shore tests.

Nev­er­the­less, geo­engi­neer­ing, also known as cli­mate engi­neer­ing, is con­tro­ver­sial on eth­i­cal grounds.

Wood ar­gues that “for cli­mate, we’re no longer in an era of ‘do no harm’. We are al­ter­ing the cli­mate al­ready. It’s now a case of ‘the lesser of two evils’.”

XIN­HUA

Prepa­ra­tion for ad­mis­sion tests for arts in­sti­tu­tions has started with train­ing in sing­ing, draw­ing, danc­ing and act­ing. Most of China’s col­leges for the arts con­duct their ad­mis­sion tests ( around Fe­bru­ary, four months be­fore the an­nual col­lege en­trance ex­am­i­na­tion. (Above) High School stu­dents in Taiyuan, in Shanxi prov­ince, at an art class.

REUTERS

A child cools off in a foun­tain in late July in Shang­hai.

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