month, the State Council of China (its main administrative body) announced that
it was planning to expand its weather-modification efforts to cover an area of
about 5.5 million square kilometers, which is more than half the size of the United
States. In addition to rainmaking (which
the announcement called “precipitation control”), the government-funded
efforts include prevention of hailstorms, enhanced accuracy of weather forecasts,
and emergency response plans to deal with crises such as forest fires.
This is not
China’s first venture into weather modification. To prevent rain from dampening the
festivitives at the opening of the 2008 Olympics in Beijing on August 8 of that
year, over a thousand rockets filled with silver iodide crystals were fired
into the skies prior to the event.
Whether the party would have been rained out without the rockets is
something we’ll never know, but the Party leaders didn’t want to take a chance
that rain would spoil their parade.
things such as Indian rain dances, the history of scientific weather
modification goes back to the late 1940s, when meteorologist Bernard Vonnegut
(brother of author Kurt) and the Nobelist Irving Langmuir independently found
ways to encourage clouds to form precipitation.
Vonnegut’s method involved silver iodide crystals, and the U. S. Army
showed in large-scale experiments that spreading finely-divided crystals into
actual clouds could cause or increase rainfall under certain conditions.
In the U. S.,
large-scale cloud-seeding efforts are no longer common, although numerous
experiments with hurricanes and conventional storms were carried out as late as
the 1970s. For one thing, it is
difficult to do a controlled experiment with cloud seeding, as no two clouds
are ever alike and the ideal of changing only one variable (to seed or not to
seed) can never be achieved.
Consequently, the typical outcome of an experiment, which can cost many
thousands of dollars in flight time, shells, or rockets, is “well, maybe
it did something, but we’re not sure.” Another issue is
that if more rain comes down in location A, that same rain can’t also fall in
location B, and if A and B are in different states, for example, you have a
potential conflict between administrative entities.
That may be one
reason that, after employing weather modification to a limited extent in theVietnam
War, the U. S. signed the Environmental Modification Convention in 1978, which bans the use of weather modification for
hostile purposes. The Peoples’ Republic
of China is also a participant in that convention, but that may not make
adjacent countries such as India feel much better, as China could always claim
that their cloud seeding was for peaceful purposes.
“geoengineering” is usually reserved for technological activities
that would affect the entire globe, not just a part of it. For example, at various times scientists have
floated the idea that to combat global warming, we should inject a lot of
sulfur dioxide particles into the air in order to reduce the influx of radiation
to the earth’s surface and counteract the greenhouse effect of rising carbon
dioxide levels in the atmosphere. So
far, weather modification efforts on the scale that we have seen historically
don’t amount to geoengineering. But if
the area in which such work is being done gets large enough, and 5.5 million
square kilometers is pretty large, then you can begin to wonder whether we are
putting the robustness of large-scale weather systems to a test.
We already know
that seemingly subtle shifts in things such as the El Niño circulation off the Pacific
coast of South America can have significant effects on our weather here in
North America. I don’t know anything
about typical weather patterns in the Far East, but it only stands to reason
that mucking around with the weather over a large enough area of China is going
to have some kind of effect in areas outside the region as well.
Of course, this
assumes that everything the State Council wants to do is successful. If the history of weather modification tells
us anything, it says that the best-laid plans in this field turn out to work
less well than the designers hoped they would.
But most of the large-scale experiments in cloud seeding were carried
out decades ago, before the advent of modern supercomputer-based weather
modeling and enhanced automated weather data acquisition. It’s quite possible that with modern
weather-forecasting technology, something closer to a truly controlled
experiment can be carried out that will give us a better idea of whether all
that silver iodide is doing any good, or whether it’s just as useless as shooting
China has the
dubious advantage of not having to worry about interstate lawsuits or any of
the other administrative inconveniences that go with democracy. Dictatorships can do large-scale, long-term
things that democracies find difficult.
It’s not an advantage that I personally think is worth the cost, but if
the State Council decides to do a thing, there’s not much anybody else can do
to stop them, whether it’s weather modification or a one-child policy.
If the experiments
turn out to be successful, I doubt that China will be very generous in sharing
the results with the rest of the world, except maybe to brag. And even if everything works as well as they
hope, I’m not sure how applicable the results will be for the rest of the
world, unless Russia or some other country dealing with huge land masses gets
heard someone say, “water is the new oil,” meaning that as populations
increase and live in cities with modern water supplies, the need for clean
water may outstrip the need for fossil fuels.
While water resources will always be important, if weather modification
turns out to be as useful as China thinks, that will add a new factor to the
question of where future generations will find enough water to use. My suspicion is that the basic natural
processes that put water in the air in the first place are not going to change
that much by means of weather modification, and any changes China or any other
country can make will be relatively small-scale and short-term. But I’ve been wrong before.
Sources: The South China Morning Post carried
an article describing the Chinese State Council’s announcement of its plans for
weather modification at https://www.cnn.com/2020/12/03/asia/china-weather-modification-cloud-seeding-intl-hnk/.
I also referred to the Wikipedia
articles on cloud seeding, the Environmental Modification Convention, and El Niño.