MadSci Network: Environment & Ecology |
Dear Kelly,
Cloud seeding is one of the methods used to intentionally modify
weather, with examples including increasing rain or snow, making
hailstorms less destructive by making the hailstones smaller, and
clearing fog at airports.
Silver iodide, one of the substances used for cloud seeding, is
generally regarded as a harmless material, especially in the
relatively small amounts used in cloud seeding. My impression on
the social justice issue is that there isn’t enough hard
scientific data to support suggestions that weather modification
may have the effect of bringing rain to an area by taking it away
from another, even though it might seem like this could happen.
The atmosphere holds a large amount of moisture as humidity which
does not fall as rain or snow even though there may be clouds
present, until one or a combination of several different
conditions are right for precipitation to occur. Cloud seeding
seeks to start off some of these conditions and cause rain drops
or snow flakes to start forming. In contrast to cloud seeding,
many forms of air pollution get in the way of the formation of
rain drops or snow flakes and prevent precipitation from
occurring. From an environmental perspective, this is probably a
more serious threat to the balance of the moisture budget than
cloud seeding could be.
The science of cloud seeding has not been perfected and most of
the cloud seeding that is going on is still experimental. Some
cloud seeding efforts have actually reduced the amount of
rainfall, rather than increase it. The consensus among observers
seems to be that it is not the best solution to rainfall
deficiency or water resource management problems.
The internet links below provide a lot more information on this
subject. I hope my answer is useful.
Dauda Ladipo.
ENCYCLOPÆDIA BRITANNICA: weather modification
britannica.com
article
MATERIAL SAFETY DATA SHEETS for Silver Iodide:
ESPI-Metals.com
(pdf document)
ucsd.edu
Does Weather Modification Really Work? by Ric Jensen, Information
Specialist, Texas Water Resources Institute
twri.tamu.edu
Air Pollution Is Stifling Precipitation, Study Finds Weather:
Tiny particulates inhibit rain and snowfall, with major
implications for the Southland, experts say. By MARLA CONE, Times
Environmental Writer
latimes.com
Try the links in the MadSci Library for more information on Environment & Ecology.