Is manipulating the weather an answer to water scarcity?
To combat water scarcity some countries are looking to the sky: As Ethiopia prepares to resume filling the Grand Ethiopian Renaissance Dam during its rainy season in July and August, the country’s prime minister earlier this year announced that his government had turned to an increasingly popular technology to speed up the process. Weather modification techniques used to artificially trigger rain, otherwise known as cloud seeding, will be deployed to assist the country’s hydropower generation abilities, Abiy Ahmed said in April, in reference to the GERD. And with little over a month before the rains start, this week a senior official at the country’s meteorological authority said that 10 agencies had begun cloud seeding.
Cloud seeding- a primer: The science behind cloud seeding isn't actually new, and has been around since the 1940s, thanks to the work of atmospheric scientist Bernard Vonnegut (yes, author Kurt Vonnegut’s older brother). Vonnegut was the first to discover that you could manipulate clouds into precipitation by sprinkling them with a little silver iodide. To do this on a larger scale, scientists fix containers full of the chemical compound to the wings of planes which, once in the air, are able to release it into cloud formations. The silver iodide triggers water vapor to more quickly freeze before it eventually melts and falls to the ground in the form of rain or snow.
Cloud seeding may be facilitating Egypt’s greatest existential threat — but it could also help us: Countries concerned about the future prospects for droughts and water insecurity have increasingly been turning to cloud seeding technology. While the process is far from widespread, recent studies have suggested that seeding is effective in increasing rainfall, thereby helping curb short term water scarcity, and several countries around the world are beginning to take it seriously.
China plans to take cloud seeding to a whole new level: The Chinese government has long been one of cloud seeding’s biggest supporters, and has the world’s largest seeding system. It’s now planning a dramatic expansion of its program, pledging at the end of 2020 to expand it to cover 5.5 mn sq km — 1.5x the size of India. Beijing spent more than USD 1.3 bn on weather modification programs between 2012 and 2017.
And our Gulf neighbors are funding a project that could change how we think about cloud seeding: The UAE’s Rain Enhancement Research Program (RERP) has been experimenting with cloud seeding since 2019, and claims it is capable of increasing rainfall by some 10-15% — and in some rare cases by up to 30%. Now, scientists are preparing to pilot an experimental technique to create rain: a team of researchers from the UK’s University of Reading will soon launch a fleet of custom drones into the sky above Dubai to shoot electrical charges into the atmosphere. The theory is that electrically-charged droplets are more likely to grow in size, and thus are less likely to evaporate before they reach the ground.
But the UAE may have already felt the effects of overreach: At the end of 2019, the country experienced huge downpours that left roads, homes and the Dubai Mall underwater. Eight cloud-seeding operations completed by the RERP a few weeks prior may have had something to do with it, Wired suggests.
Parts of the US are looking to seed clouds to stave off droughts: A number of desperate states in the US west where droughts are increasingly becoming the norm are now considering turning to the technology to ease the stress on water supplies. Idaho has already been at it for years, spending upwards of USD 3 mn annually on cloud seeding since 2003 to increase water flowing through its hydroelectric dams.
Egypt has growing concerns about water security: Backed into a corner by climate change and the threat of the GERD cutting off vital supplies of Nile water, Egypt is searching for solutions. So far, policymakers have focused on reducing waste via new, more efficient irrigation techniques, finding new sources of water — primarily via desalination — and reusing water by building more treatment plants.
Can cloud seeding form part of the solution? Weather modification techniques, including cloud seeding, could be effective in reducing the impact of GERD on the Aswan High Dam’s reservoirs, as well as replenishing water lost through evaporation, A 2019 research paper suggests. Cloud seeding directly above the high dam reservoir could be most effective prior to the flood season in July/August, while seeding along the North Coast could be effective during winter months, provided a system of wells and reservoirs is built to capture the excess rain. Fog and dew harvesting is also a technique worth considering in Egypt, though fog collectors must be built to withstand the strong khamasin winds, the paper suggests.
The Egyptian Meteorological Authority made some noise about exploring cloud seeing in 2016, and linked up with a team of German experts to conduct feasibility studies. The feasibility studies were still underway in 2019, the EMA said, but we haven’t heard much on the plan since then.