Weather Mod Critical Issues Report

• Project Type: General OWC
• Project Name: Weather Modification
• Title: Critical Issues in Weather Modification Research
• Date: 1/1/2004
• Water Conservation - Doc Type: Final Report

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2. Introduction

The National Research Council (NRC) released a report on 13 October 2003,
titled "Critical Issues in Weather Modification Research" (NRC, 2003). The national
press highlighted one of the committee's conclusions that "there still is no convincing
scientific proof of the efficacy of intentional weather modification efforts, In some
instances there are strong indications of induced changes, but the evidence has not been
subjected to tests of significance and reproducibility". The NRC report makes a case for
the decline of coordinated, sustained funding of research in weather modification during
the last three decades. This decline in funding is cited as both an effect of and a cause of
a lack of scientific proof of the effectiveness of cloud seeding. The panel was careful to
say that, "this does not challenge the scientific basis of weather modification concepts.
Rather it is the absence of adequate understanding of critical atmospheric processes that,
in turn, lead to a failure in producing predictable, detectable and verifiable results".

The Weather Modification Association (WMA) is an association of scientists,
engineers, economists, water management professionals, government and private
business people, and others who have spent and continue to spend their careers working
in the field of weather modification. The WMA's executive committee believes that it is
the association's responsibility to review the NRC report and to offer scientific and
operational perspectives, supplemental information, rebuttal, and further
recommendations. Taking this action is consistent with the WMA's vision, mission, and
charter; see htto://www.weathermodification.org/organization.htm. The executive
committee charged the president, Richard Stone, to appoint a panel of WMA members to
provide an assessment and response to the NRC report, to update the members and
provide additional information to the public. A balanced panel was formed in early
November composed of six members with expertise in hail suppression, winter
orographic cloud seeding, precipitation enhancement, and numerical modeling.

The panel met in Fort Collins on December 5 and 6 to begin to prepare this report.
All members except George Bomar were able to attend the meeting. He participated via
e-mail and phone calls, In addition the members of the WMA were asked to provide
information and ideas to the panel and to review an early version of the draft response.
Many WMA members provided input. The panel takes full responsibility for the contents
of this response. The members of the WMA panel and their backgrounds are given in the
Appendix.

The statement in the NRC report of "no convincing scientific proof...." depends
on their definition of scientific proof that involves randomized experiments, strong
statistical support, extensive physical measurements and understanding, and replication.
This is a very high standard for a system as complex as the atmosphere. They conclude,
"There is ample evidence that inadvertent weather and global climate modification (e.g.,
Greenhouse gases affecting global temperatures and anthropogenic aerosols affecting
cloud properties) is a reality", They are thus clearly maintaining "higher bar" criteria for
acceptance for planned weather modification. In our opinion, all should be evaluated with
the same criteria. If inadvertent modification of weather and climate were held to the

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