The 2008 Summer Olympic Games in Beijing, China, will be a display of athletic excellence and, for the first time on an international stage, technological advances in weather modification. The Chinese Meteorological Administration (CMA) plans to fire hundreds of rockets containing silver iodine and dry ice capsules into the upper atmosphere to bring rainfall prior to the opening ceremonies on August 8, 2008. [1] This is not a new practice in China, which invests more than $40 million in weather modification technology annually. [2] In the United States, however, controversy over the effectiveness and safety of weather modification has limited the use of this technology. While ten U.S. states currently have operational cloud seeding programs, there is no federal funding devoted to weather modification technology at this time. [3] Senate Bill 1807 and House Bill 3445, identical bills introduced July 17, 2007, propose to establish a Weather Mitigation Advisory and Research Board to federally fund weather modification research with $10 million per annum. [4] These bills are important because more research is needed to create federal laws and policies, thus enabling the United States to effectively implement useful weather modification technologies.
            This article will provide a brief background on weather modification technology and its legal history in the United States before turning to the legislation pending in Congress that may significantly alter the use of weather modification technology in the United States.

Weather Modification Technology in the United States
            The most common weather modification activity currently in use is cloud seeding. Cloud seeding programs can be targeted toward precipitation enhancement, fog dispersal, hail suppression, or severe weather modification of lightning, hurricanes, and tornadoes. In 1946, Vincent Schaefer led an experiment in which dry ice pellets were dropped out of an airplane at 14,000 feet into clouds above Schenectady, New York. [5] The result was induced snowfall and the birth of modern weather modification. In 2001 there were at least 66 cloud seeding programs designed for hail suppression and snow or rain enhancement in the United States. [6] These programs are located in western states and are supported by local or state governments. [7] These are the only weather modification programs currently being practiced in the United States, due to skepticism toward weather modification techniques and a lack of federal funding for research. [8] As a result, scientific knowledge of the positive and negative effects of weather modification is limited.
            Unknown variables make it difficult to assess the effectiveness of weather modification operations. There are several problems that create uncertainty among scientists. First, evaluating the effects of weather modification requires a comparison between the observed effects and what would have naturally occurred. [9] This is difficult given the inexact nature of weather prediction. [10] Second, scientists have limited knowledge regarding the chain of individual processes within clouds that cause precipitation, making it difficult to distinguish between naturally and artificially caused weather conditions. [11] Furthermore, due to the varying nature of weather patterns, long experimental periods are needed to obtain accurate data. [12] To date, very few experiments have spanned long enough time frames to account for the effects of variation in weather patterns. [13] Weather modification is also specific to the particular location in which it is performed. Positive results in one location and negative results in another are entirely possible, even under the same conditions. [14] Finally, mathematical models cannot accurately depict natural atmospheric conditions and therefore offer limited insight. These difficulties lead to debates among scientists regarding the effectiveness of weather modification, although it is generally accepted that cloud seeding can cause increased precipitation in specific circumstances. [15]
            The adverse effects of weather modification are just as difficult to measure as their positive counterparts. One negative effect that has been suggested is that cloud seeding can cause severe weather or drought in locations that are “downwind” from the target site. [16] In addition, the introduction of chemicals into rainwater also raises questions about dangerous toxicity levels in the soil and groundwater. [17]
            Although there has been significant progress in atmospheric physics and weather modification technologies, further research is needed to solve the still existing uncertainties. Efforts must first be directed toward understanding how the atmosphere behaves. [18] Only then can scientists evaluate the effectiveness of weather modification technologies.

Weather Modification Law in the United States
            Historically, liability for the potential adverse effects of weather modification has been dealt with through state negligence and trespass law. Potential victims have sought injunctions prohibiting future weather modification activities or sued for damages allegedly caused by weather modification. [19] While injunctions were sometimes successful, [20] there have been no cases in the U.S. where defendants have been found liable for damages due to weather modification activities. [21] The problem with these remedies is the causation requirement. Given that scientists have difficulty measuring the effects of weather modification, it is impossible for plaintiffs to establish that these activities caused the adverse weather conditions. Colorado and Wisconsin have attempted to address this problem with statutes that make the failure to follow state weather modification regulations negligence per se. [22]
            There are 32 states that currently have legislation relating to weather modification; [23] all statutes require that the individual carrying out the weather modification can prove his or her competence in that area. [24] A Bachelor’s degree in a related field is usually sufficient to satisfy this requirement. [25] Another common feature of the statutes requires companies to either post bond or obtain liability insurance, ensuring that the company has the financial resources to compensate anyone harmed by their activities. [26] Some states also requite a “Notice of Intention” to be published in the local newspaper. [27]
            While these state laws are a start, one major problem with state regulation of weather modification is that clouds are constantly in motion. [28] Cloud seeding in one state might later cause rain in another. Despite these interstate concerns, federal law only requires that anyone engaging in weather modification report their activities to the Secretary of Commerce. [29]
            Another major legal issue regarding cloud seeding can be framed as a property rights question: who owns the water in the clouds? Many believe that cloud seeding is unethical because it is in essence “robbing Peter to pay Paul.” [30] The theory is that inducing rainfall in one area deprives others of the rainfall that is rightfully theirs. However, other scientists have rebutted this argument, arguing instead that “cloud seeding does not divert rain from falling in one place in favor of another.” [31] Although clouds normally contain more than enough moisture to precipitate, “[c]louds just don’t always possess a natural precipitation initiation mechanism.” [32] The chemicals used in cloud seeding help create precipitation by providing this initiation mechanism.
            Although federal regulation is needed, effective laws and policies cannot be implemented until proper research and evaluation of weather modification is complete. “Only with clear scientific understand can the legislature meet the science to create sound policy…” on weather modification. [33] Once the scientific data is made available, federal legislation can help promote this potentially useful technology. New legislation is also needed to update the insufficient remedies that are currently provided under state law.

The Future of Weather Modification Technology in the United States
            Senate Bill 1807 and House Bill 3445 could lead to the revolution of weather modification research in the United States. These identical bills seek to establish a Weather Mitigation Advisory and Research Board which would “coordinate the national research and development program on weather mitigation….” [34] Specifically, the Board would coordinate research including:

1. “Research related to cloud and precipitation physics
2. Cloud dynamics and cloud modeling
3. Improving cloud seeding-related technologies
4. Severe weather and storm research
5. Research related to potential adverse affects of weather mitigation” [35]

and would be authorized to appropriate $10 million per year until 2017 for research. [36]
            A Weather Mitigation Advisory and Research Board would be able to objectively analyze the research and developments in the field and determine the positive and negative effects of weather modification. With a better understanding of the atmosphere and the weather technology available, the Board could advise legislators on a weather modification policy that would protect citizens while utilizing the newest technology in a safe and efficient manner.
            There is no indication of whether these current bills will make any noise in Congress. A similar bill, Senate Bill 517, was introduced March 3, 2005 but was never passed. [37] Senate Bill 517 sought to establish a Weather Modification Operations and Research Board and also purported to allocate $10 million per year to weather modification research. [38]

Conclusion
The near future of weather modification technology in the United States will likely depend on the outcome of Senate Bill 1807 and House Bill 3445 because of the need for further research and subsequent funding in the field. Until scientists conduct this research and learn more about the atmosphere and weather modification, “[t]he reality remains that desperate times call for desperate measures and when states face difficult and costly droughts they will continue to fall back on the potential and unproven benefits of cloud seeding….” [39]