Threading through clouds, often with shaky turbulence and occasional thunder, 71-year-old pilot Gary Walker burns the flares on his plane’s wings, releasing chemicals as he flies.
“It can be very rough as you get close to some of those clouds,” he said.
Walker, chief executive of Texas-based aviation company SOAR, carries out an increasingly popular — and in some cases controversial — effort to chemically impregnate clouds to increase rainfall.
To cope with searing global temperatures, protracted droughts and chronic water shortages, countries from the US to China are turning to “cloud seeding,” which aims to boost rainfall in dry areas.
The process is hardly new.
First trialled in the US, it is now discreetly used in more than 50 nations, from Mali to India and Puerto Rico.
China, though, has the biggest cloud-seeding operation, which it utilizes not only to increase rainfall, but also to avoid hailstorms that can devastate farm crops.
Beijing also turned to cloud seeding in the buildup to the 2008 Summer Olympic Games, to try to avoid rain during its spectacular opening ceremony.
While the success of cloud-seeding efforts remains in question, commercial use of the technology is growing.
US and European companies are testing remote-controlled drones to seed clouds and promising rain-free wedding ceremonies by “bursting” clouds ahead of the big day.
Still, the technology cannot do much to tease rain from a cloud-free sky, experts say.
“In extreme heat or drought conditions there are no clouds. Nobody can make clouds,” said Roelof Bruintjes, a senior scientist who works on weather modification for the US National Center for Atmospheric Research.
Rather, the idea of cloud seeding is to make rain form more efficiently inside clouds so more water comes down, he said.
Such artificial rainmaking is akin to giving clouds vitamins, or farmers applying fertilizers to boost their crop yields, he said.
To seed a cloud, pilots introduce a chemical agent, commonly silver iodide. It draws moisture to itself, allowing the cloud’s water vapor to condense into droplets and produce rain, according to the World Meteorological Organization (WMO).
Does the process work?
“There are still a lot of unknowns and a lot more research to be done, but ... if it can be done successfully it will have huge benefits, especially in water-scarce areas,” WMO director of research Deon Terblanche said.
GLOBAL REVIEW
The WMO is carrying out a global review of knowledge on cloud seeding, with the aim of preparing official advice and a comprehensive database of projects as the number of nations seeking to invest in the technology rises, Terblanche said.
Although the amounts of silver iodide used for most cloud seeding are too small to hurt the environment or public health, and do not present any significant risk, he said, the chemical in very large quantities can be toxic.
Apart from environmental risks, cloud seeding could also lead to geopolitical spats if over-used in one region, depriving areas downwind of rainfall.
However, the main stumbling block is measuring the technique’s success.
Terblanche said in some areas where cloud seeding is used, rainfall has increased by more than 10 percent, but there could also be knock-on effects that are harder to quantify, such as increased river runoff.
Terblanche believes cloud seeding should not be seen as the best way to deal with water shortages. In particular, nations need to work on capturing and managing natural rainfall to take advantage of heavier downpours, as rain becomes less reliable.
In California’s Los Angeles County, cloud seeding has been used for more than half a century, including to combat a recent long drought.
Clouds are commonly seeded by placing canisters atop the San Gabriel Mountains, Los Angeles County Department of Public Works spokesman Kerjon Lee said.
The canisters are then ignited remotely — “like sparklers” — with smoke carrying the chemical seeding agent up to the clouds, Lee said.
The county has also worked on creating more lakes and other rainfall capture areas to store water, he added.
‘HELPING HAND’
He described cloud seeding as “giving mother nature a helping hand.”
“It’s a practice that we believe is beneficial and, as conditions warrant, we’ll be using it again,” he said.
However, it is just one tool in a broader strategy to deal with drought, he added.
As temperatures continue to rise, largely as a result of climate change — last year was the hottest on record, according to the WMO — more nations are expected to explore ways to boost rainfall.
The Persian Gulf, with its large swathes of golden desert, is already one of the hottest places on Earth. The mercury in Kuwait last year soared to 54?C, according to the WMO.
In the nearby United Arab Emirates, officials at the National Center of Meteorology and Seismology (NCMS) say cloud seeding efforts there are working.
Considered a leader in “rain enhancement,” the nation now uses six specialized aircraft for seeding flights. It has witnessed an increase in rainfall of about 10 to 15 percent in polluted air, and 30 to 35 percent in clean air, officials said.
NCMS director of research and development Omar al-Yazidi believes science shows cloud seeding is safe for the environment and the public. He thinks such efforts will only grow in popularity.
In 2015, the center began offering US$5 million in grant money via its “Research Program for Rain Enhancement Science” to researchers working on water security challenges.
“The global water shortage is worsening in many parts of the world, so the demand for fresh water is increasing. Cloud seeding could be one of the methods that can contribute to alleviating the water problem,” said Khalifa University of Science and Technology professor Linda Zou, one of three winners of the first round of funding.
Zou is looking into using nanotechnology to develop novel cloud-seeding materials.
As climate change brings hotter and drier conditions in some parts of the world, more governments are expected to seek novel ways to keep their populations cool and their land moist.
That might herald a growing role for technologies such as cloud seeding, experts say.
“Water is the basic sustenance of life,” Bruintjes said. “If there is no water, there is no life.”
Could Asia be on the verge of a new wave of nuclear proliferation? A look back at the early history of the North Atlantic Treaty Organization (NATO), which recently celebrated its 75th anniversary, illuminates some reasons for concern in the Indo-Pacific today. US Secretary of Defense Lloyd Austin recently described NATO as “the most powerful and successful alliance in history,” but the organization’s early years were not without challenges. At its inception, the signing of the North Atlantic Treaty marked a sea change in American strategic thinking. The United States had been intent on withdrawing from Europe in the years following
My wife and I spent the week in the interior of Taiwan where Shuyuan spent her childhood. In that town there is a street that functions as an open farmer’s market. Walk along that street, as Shuyuan did yesterday, and it is next to impossible to come home empty-handed. Some mangoes that looked vaguely like others we had seen around here ended up on our table. Shuyuan told how she had bought them from a little old farmer woman from the countryside who said the mangoes were from a very old tree she had on her property. The big surprise
The issue of China’s overcapacity has drawn greater global attention recently, with US Secretary of the Treasury Janet Yellen urging Beijing to address its excess production in key industries during her visit to China last week. Meanwhile in Brussels, European Commission President Ursula von der Leyen last week said that Europe must have a tough talk with China on its perceived overcapacity and unfair trade practices. The remarks by Yellen and Von der Leyen come as China’s economy is undergoing a painful transition. Beijing is trying to steer the world’s second-largest economy out of a COVID-19 slump, the property crisis and
As former president Ma Ying-jeou (馬英九) wrapped up his visit to the People’s Republic of China, he received his share of attention. Certainly, the trip must be seen within the full context of Ma’s life, that is, his eight-year presidency, the Sunflower movement and his failed Economic Cooperation Framework Agreement, as well as his eight years as Taipei mayor with its posturing, accusations of money laundering, and ups and downs. Through all that, basic questions stand out: “What drives Ma? What is his end game?” Having observed and commented on Ma for decades, it is all ironically reminiscent of former US president Harry