Cloud Seeding Overdose

The big news this past weekend was more about the weather than the climate. While the week began with lots of news about Chinese climate discussions with a number of key partners, as well as key U.S. China trade talks, by the weekend, the main talk of Beijing was astonishingly early snow.

Beijing, which generally has little precipitation in the winter, and rarely before December, saw a snowstorm start October 31 and build up through much of November 1. Beijingers were then surprised to learn that, in fact, the snow was seeded by the local meteorological bureau, which had hoped for rain and had not predicted the unseasonably cold temperatures. The Daily Mail has some great pictures of the storm here.

Beijing city officials responded to the early snowstorm by turning on the heat two weeks early. Beijing and most northern cities are heated through district heating systems that have official start and stop dates. For Beijing and neighboring provinces heat is provided only November 15 through March 15. As a long-time Beijing resident, I can tell you it is generally pretty chilly indoors by U.S. standards by at least November 1, and even late October can feel cold sometimes. In fact, when I used to live in a diplomatic compound in Beijing the Foreign Ministry would turn on the heat for the international crowd a full month earlier to keep us from getting chilled. But nowadays lots of city-dwellers have more choices, and they can turn on reverse-cycle air conditioners that can act as space heaters. If the city doesn’t turn on the heat early when the mercury dips below freezing, it faces a spike in electricity demand from such devices.

Beijing residents are familiar with spring and summer cloud-seeding, but this winter storm seemed to take everyone by surprise. In fact, it looks like it is more common than we’d realized. When looking on the web at the recent story, I saw that actually we’d had a seeded snowstorm in Beijing just this past February.

Although cloud seeding in China (and in Russia recently as well) elicits a lot of Western press interest, cloud seeding actually seems pretty widespread in the U.S too. A quick web search revealed lots of discussion of cloud seeding programs in Nevada, and the State of Utah has its own government cloud seeding web page which claims winter seeding increases precipitation 14-20%. Utah lists four separate projects operating in “water year 2009.”

Photo by J.A.C.K. under a Creative Commons Attribution-Noncommercial-No Derivative Works license.