Cloud-seeding theories are difficult to substantiate

ORIGINALLY WRITTEN BY KATHLEEN W. WARD ? KSU
In wide-open western Kansas, rain and hail are serious business with an impact on every wallet. But attempts to alter such weather are meeting increasing controversy.

Nay-sayers think past attempts to reduce hail damage have limited vital rainfall. Yea-sayers believe history has shown cloud seeding brings sizeable benefits.

Recent research at Kansas State University indicates, however, the facts aren?t clear-cut. So far, no one can truly measure what happens when humans try to interject a kick in weather?s get-along.

Since 1975, the Western Kansas Weather Modification Program (WKWMP) has been seeding clouds to suppress hail and promote rain in southwestern Kansas.

In 1997, the program expanded into northwest Kansas and became the largest aviation-based cloud-seeding program of its kind in the nation.

Roughly 55 percent of last year?s WKWMP funding came from individual counties and groundwater management districts in western Kansas. The balance came from the state.

By 1998, however, northwest Kansas had a new group?the Concerned Citizens for Natural Weather ?organized to formally oppose cloud seeding.

?Given what?s known now, neither side in the debate is right…or wrong…or likely to change its mind,? said K-State Research and Extension economist Terry Kastens. ?Opponents have some scientific backing for their anti-seeding stance, but an equal amount of research refutes their claims.?

The modern science of weather modification emerged shortly after World War II. It was an offshoot of General Electric?s attempts to prevent icing on aircraft wings.

?Science got promising results in the lab. Its results were more ambiguous when applying the technology to actual clouds,? said Brian Vulgamore, who conducted K-State?s study as part of his graduate program and now farms near Scott City.

?Unfortunately, science was unable to separate fact from fiction after that, due to lack of research funding in the 1980s and ?90s.?

That?s why his study bypassed the science of modifying the weather. Instead, Vulgamore tried to assess real-life impacts. He examined both rainfall and hail in western Kansas and worked to put their outcomes in dollar terms.

?The smallest drought causes economic harm in any semi-arid farming region,? Kastens pointed out. ?Up to a point, extra rainfall brings extra economic benefits.?

But equal precipitation losses and gains don?t bring equal results. Vulgamore?s analyses suggest that an added inch of growing-season rain in western Kansas translates into an economic gain of about $18 million. A one-inch loss in rainfall translates into economic losses exceeding $19 million.

Even so, this finding provided little insight, because the study also revealed:

n Since the cloud-seeding program began, all western Kansas rainfall has fit into ?normal,? time-established patterns.

n Over the course of the program through last year, rainfall in some WKWMP target counties both exceeded and fell short of the local, long-term average. Counties outside the seeding area also experienced random increases and decreases.

n Little evidence points to the idea that WKWMP?s efforts may have caused large effects in either target area or downwind rainfall.

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