Various forms of geoengineering have gained prominence in the search for solutions to global warming. The wilder ideas – such as spraying dust into space to block some of the sun’s rays – are still being debated. However, weather modifications in the form of cloud seeding have now been implemented in various parts of the world, most recently in the western United States.
Cloud formation occurs mostly through the release of compounds such as silver iodide in clouds. The chemicals act as a kind of scaffolding that water molecules attach themselves to, becoming so heavy that they fall to the ground as rain. It’s not new technology; Countries around the world have used it for decades to generate rain for crops, and the US government even used it during the Vietnam War to increase rainfall during the monsoon season, making the terrain muddy and difficult for enemy combatants to traverse make.
But the need for cloud seeds is becoming more pressing and widespread as temperatures rise, particularly in areas that have traditionally been hot and dry. One such area is the US Southwest; New Mexico and West Texas have never been known to be lush or humid. Now that it’s getting hotter and there’s less rainfall, it’s no surprise that cloud seeding is proving useful. More surprising is the use of the technology in neighboring states that have traditionally been wetter, like Colorado, California and Utah.
The Wall Street Journal reported last weekend that all of these states (as well as Nevada, Idaho, and Mexico) have cloud seeding programs currently underway, with spending on the technology running at up to $12 million in a year.
The additional precipitation does not only affect the harvest. With water levels in key reservoirs like Lake Mead and Lake Powell recently hitting historic lows, everything from residential water supplies to hydroelectric power generation could be at risk (although Lake Powell’s water levels have risen again thanks to heavy snowfall in the Colorado Rockies this past winter has increased). this spring, up more than 41 feet since early 2023).
The St. Vrain Water District in Colorado spent $40,000 seeding winter clouds last year to increase snowfall in the surrounding mountains. One problem with cloud seeding, however, is that it’s difficult to prove that it works. There may be more precipitation after silver iodide is airborne over a particular region, but how do we know it wouldn’t have rained anyway?
However, there is ample evidence pointing to real results. A winter 2017 study in Idaho’s Payette Basin area found that cloud formation produced enough snow to fill 300 Olympic pools, compared to clouds that were not deployed.
In 2021, the UAE National Center for Meteorology began seeding clouds near Dubai. Remarkably, they used a different technique: instead of releasing silver iodide or other chemicals into the air, they used drones with charge emitters that applied an electric charge to cloud molecules. A change in the balance of charges on tiny cloud droplets causes them to coalesce and form raindrops. In the course of this activity, it rained so heavily that some streets in Dubai were flooded – a rare occurrence for the arid desert city.
Proponents of cloud formation say their data shows the technology can increase rainfall by 15 percent compared to areas where no clouds are planted. That adds up to about five centimeters of additional rain per year. That doesn’t sound like much, but especially in very dry places, it’s enough to keep crops alive and helps secure underground aquifers.
In many parts of the United States, we take water for granted. We turn on the tap and it flows out clean and plentiful. However, this may no longer be the case in the future. Water is likely to become the new gold, and finding ways to harvest more of it will be vital to our well-being and survival.
While cloud seeding is currently more viable than solutions like desalination, there is a limit to how far we can manipulate the natural order before undesirable side effects occur. For now, pumping chemicals into the clouds will give us a good tether, but over time we’ll probably have to find another way to make it rain, or abandon the driest areas altogether.
Image source: Felix Mittermeier from Pixabay