Weather Modification Law
in the USA
Copyright 2002 by Ronald B. Standler
Table of ContentsIntroduction
2. Government Licensing and
General Principles of Tort Liability
alternative to tort litigation
6. Support of Basic
7. Property Rights in Water
from Cloud Seeding
IntroductionWeather modification is the effort of man to
change naturally occurring weather, for the benefit of someone. The best-known
kind of weather modification is cloud seeding, with the goal of producing
rain or snow, suppressing hail (which can ruin crops), or weakening hurricanes.
People who live in the city do not give any thought to water: they turn
on the faucet and water appears. But water is a constant concern for farmers and
ranchers: drought can bankrupt a farmer and force a rancher to sell his/her
cattle at an undesirable price. The legal right to access water is an important
part of property law. There are many legal disputes about one person or
one state extracting "too much" water from a river and thereby
depriving everyone downstream. Because water is absolutely essential to the
financial survival of farmers and ranchers, public hearings about allocations of
water (including proposed cloud seeding) are often highly emotional events.
This essay briefly reviews governmental regulation of weather
modification, then concentrates on judicial opinions regarding
modified weather or cloud seeding and suggests how future weather
modification torts might be argued. The scope of this essay does not
cover liability for inadvertent weather modification, such as:
This essay also does not consider purely local
weather modification, such as dissipating fog in supercooled clouds at an
- release of heat or smoke from industrial smokestacks;
- injection of water vapor and particulates from jet airplane engines into
the dry stratosphere;
- release of heat and airborne particulates from cities;
- pollution from automobiles;
- global warming from release of CO2 by burning wood, coal, oil,
or natural gas; or
- removal of ozone by release of fluorocarbons into the
This essay was initially written to inform:
about the nationwide law in the USA that affects tort
liability for cloud seeding. (I am not opposed to cloud seeding, but
experienced cloud seeders and their attorneys already know, or should know, the
basic information in this essay.) This essay is intended only to present general
information about an interesting topic in law and is not legal advice for
your specific problem. See my disclaimer.
- potential plaintiffs (e.g., farmers, ranchers, and people who might be
victims of a flood),
- meteorology students, and
- attorneys and law students working in either environmental law or
of cloud seeding also makes an interesting case study in the interaction between
scientists and society: not only about the obligations and ethics of scientists,
but also about how courts have avoided deciding cases involving technical issues
about weather modification.
1. TechnologyRelease of silver iodide (AgI) into an
existing supercooled cloud (i.e., air temperature between -39 and
-5 celsius) can convert water vapor to ice crystals, which is called
sublimation. The ice crystals nucleated by the AgI will grow and local water
droplets will shrink. The latent heat released by converting water vapor (or
liquid water) to ice will increase vertical air motion inside the cloud and aid
the convective growth of the cloud. Raindrops or snowflakes will grow larger by
falling through a taller cloud. Also, moist air from evaporated moisture in the
soil will be sucked into the base of the cloud by convection (i.e., updraft),
thus increasing the total amount of water in the cloud. Perhaps 30 minutes
after the AgI release, snow may fall below the cloud. Depending on the
temperature and humidity below the cloud, the snow may change to rain, or even
evaporate, before reaching the ground.
To sharpen the focus of this
essay on the law of cloud seeding, I have moved my discussion of cloud seeding
technology to a separate document. That
document contains a discussion of:
- history of early (e.g., 1946-51) cloud seeding experiments, with emphasis
on legal issues;
- some technical problems with cloud seeding experiments;
- a few excerpts from the official policy of the American Meteorological
Society on cloud seeding technologies;
- environmental concerns and terse comments on the ethics of scientific
- the need for more basic scientific research.
2. Governmental Licensing and RegulationsVarious state
governments license and regulate commercial weather modification. These
regulations are desirable because:
- weather is part of the natural environment that belongs to everyone.
- governments regulate the allocation of water from rivers to landowners, so
it was natural for governments to also regulate attempts to enhance rainfall.
- some cloud seeders in the 1950s and 1960s were charlatans who exploited
desperate farmers in a drought, which led to government programs to license
cloud seeders, in order to protect the public.
There are two
common features of state regulations:
- ensure that commercial weather modification companies are competent (e.g.,
states often require cloud seeders to have earned at least a bachelor's degree
in meteorology or a related field, plus have experience in weather
- require companies have the resources to compensate those harmed by their
weather modification (so-called "proof of financial responsibility"). In
practice, such proof requires cloud seeders either to purchase liability
insurance or to post a bond. Minimum amounts of insurance specified in old
statutes are now woefully inadequate, because of inflation since the statute
The governmental regulation of cloud seeders is
generally a two-step process. First, the government licenses individual
cloud seeders. Second, the government grants a permit to a licensed
cloud seeder to conduct operations at a specific place and range of times.
Some states require public hearings before a cloud seeder is granted a
One of the biggest problems with state regulation of weather
modification is that the effects of weather modification commonly involve more
than one state. For example, cloud seeding in the sky above Montana might
later cause rain in North Dakota.
The following state governments,
in alphabetical order, have significant websites about weather modification
licensing and regulation:
states in the USA have statutes about weather modification. Because there are so
many statutes and because they change with time, I have chosen not to summarize
state statutes in this essay. Most states have posted their current statutes on
the Internet, so they are easily available. Readers of statutes should contact
an attorney who is licensed to practice in their state for an interpretation of
technical legal terms in the statutes.
The Federal statute
15 USC § 330 (1971) requires reporting of weather modification to
the Secretary of Commerce. Federal Regulations that implement
this statute are found at 15 CFR § 908.
3. Court CasesIt is important to know that decisions of
trial courts in the USA are not published (with the exception of some
federal cases and a very few cases in some state courts), so it is difficult to
find opinions of trial courts. Even if they were published, an opinion of a
trial court is not precedent that is binding on future trials.
Additionally, many appellate court cases in the USA are also
unpublished and also can not be found conveniently.
there is no convenient way to find all of the cases in the USA involving
a specific topic or legal issue. However, the following list is what I found in
May 1997 and September 2002 with a search of the comprehensive Westlaw
ALLCASES database, plus what I found by following footnotes in law review
I list the cases in chronological order in this essay, so the
reader can easily follow the historical development of a national phenomenon.
If I were writing a legal brief, I would use the conventional citation
order given in the Bluebook. I cite articles and books in the
(Author, year, page) format; complete bibliographic data is given below.
two basic ways that people in the USA can file litigation in court regarding
- Before the cloud seeding occurs, potential victims may apply to a court
for an injunction prohibiting any future attempt at weather modification.
Before an injunction can be issued, the plaintiff must be able to show an
"irreparable harm" (i.e., destruction of something unique that can not be
replaced) or "no adequate remedy at law" (i.e., money damages in either
contract or tort litigation would not adequately compensate plaintiff).
- After the allegedly modified weather causes damage to crops or buildings,
the victims can sue the people who allegedly caused the modification in
New York 1950Slutsky v. City of New York, 97
N.Y.S.2d 238 (Sup.Ct. 1950).
New York City was conducting
"experiments to induce rain artificially", in order to alleviate the "severe
drought" that had diminished the City's water supply. The Plaintiff,
Slutsky, sought an injunction to prohibit these experiments, because he feared
the rain would interfere with his business, which was a country club and resort
in Ulster County, north of New York City.
court, in a terse opinion, denied the injunction and said:
- Apart from the legal defects in plaintiffs' suit (since they clearly have
no vested property rights in the clouds or moisture therein), the factual
situation fails to demonstrate any possible irreparable injury to plaintiffs.
- 97 N.Y.S.2d at 239.
- The final paragraph of the opinion says:
- Contrasted with plaintiff's unfounded speculations as to possible damage,
the affidavits of the experts for the City show that the experiments have
reached a stage where it might reasonably be expected that rainfall may be
both induced and controlled. This court must balance the conflicting interests
between a remote possibility of inconvenience to plaintiffs' resort and its
guests with the problem of maintaining and supplying the inhabitants of the
City of New York and surrounding areas, with a population of about
10 million inhabitants, with an adequate supply of pure and wholesome
water. The relief which plaintiffs ask is opposed to the general welfare and
public good; and the dangers which plaintiffs apprehend are purely
speculative. This court will not protect a possible private injury at the
expense of a positive public advantage. Since plaintiffs have shown neither a
factual nor legal basis for the drastic relief that they seek, the motion for
a temporary injunction is denied.
- 97 N.Y.S.2d at 240.
The parenthetical remark about "no vested
property rights" is a totally unsupported conclusion. Nowhere in this terse
opinion is any discussion of property rights, vested or otherwise. This
terse opinion cites no cases, no statutes, no books, and
no scholarly articles in legal journals. Furthermore, the promise
of experiments to increase rainfall, which the court accepts as reality, was,
in fact, highly speculative in 1950. Indeed, the judge properly referred to
the attempts at rainfall enhancement as an "experiment" five times in
one page. Despite what the judge said, there was a possibility that the
plaintiffs' business might suffer from heavy rainfall, and there is also a
possibility that the experiments would be ineffective in enhancing
rainfall. Nonetheless, it was appropriate to balance the harms that might be
suffered by one resort owner vs. ten million thirsty people in the City,
and then rule in favor of the City. In my opinion, this judge reached the
correct result, after mentioning the wrong reason (i.e., "no vested property
rights"), no reasons (i.e., failing to cite any authority), and the
right reason (i.e., the balancing of equities).
The opinion in this
case was subsequently criticized by Judge MacPhail in Pennsylvania:
following the citation to the Marquette Law Review, one finds that
Comment (which was written by three students while in law school) says only the
following about the Slutsky case:
- The court's language concerning vested property rights in clouds and
moisture was dicta, unsupported by legal authority or reason and was
not favorably received. See 34 Marquette Law Review 262.
- Pennsylvania Natural Weather Assn. v. Blue Ridge Weather Modification
Assn., 44 Pa. D. & C. at 757,
1968 WL 6708 at *6 (Pa.Com.Pl. 1968).
- ... the court offers no substantial reason for its parenthetical statement
that a property owner has "no vested property rights in the clouds or the
moisture therein." Indeed it is not at all clear just what the court means by
its statement, for while it is true that a landowner has no vested property
right in the moisture or clouds while over another man's land, it does not
necessarily follow that he has no rights whatsoever to the natural benefits
which will accrue to him from the normal rainfall. .... Thus the
Slutsky case, while making a rather categorical statement regarding the
rights of property owners in the clouds overhead, actually throws little light
upon the problem involved.
- Paul Binzak, Richard P. Buellesbach, Irving Zirbel, Comment: "Rights of
Private Land Owners as Against Artificial Rain Makers," 34 Marquette Law
Review 262, 264-65, Spring 1951.
Oklahoma 1954Samples v. Irving P. Krick, Inc.,
Civil Nrs. 6212, 6223, 6224 (W.D.Okla. 22 Dec 1954).
is an unreported case that has been mentioned briefly in several law
review articles. See, e.g., Grauer & Erickson (1956, p. 109),
Oppenheimer (1958, p. 319), and Davis (1974, p. 413). This
was apparently the first weather modification case in the USA to be presented to
Plaintiff alleged that cloud seeding by Krick caused a flood on
18-19 November 1953 in Oklahoma City. The jury returned a verdict
for the defendant. Despite the immense importance of this case both to the
meteorology community and to the developing area of weather modification law,
the federal judge did not prepare a written opinion for this case.
Incidentally, Krick was the chairman of the meteorology department at
California Institute of Technology from 1933 to 1948. That university abolished
the entire meteorology department and fired Krick in 1948, apparently because
Krick was spending too much time on his private consulting business that
forecasted the weather for paying clients, and not enough time on scholarly
research in atmospheric physics. (See the essay
by Judith Goodstein, a historian of science at California Institute of
Technology.) Krick was one of the most famous commercial cloud seeders in the
USA during the 1950s and 1960s. Among other flamboyant statements, Krick claimed
he could predict weather more than one year in advance, with approximately
80% accuracy, using proprietary technology that he had developed.
I have the impression that most meteorologists who were familiar
with Krick's work believed that he was unprofessional and a fraud.
Washington state 1956Auvil Orchard Company, Inc. v.
Weather Modification, Inc., Nr. 19268 (Superior Court, Chelan County,
This is an unreported case that has been mentioned
briefly in several law review articles. See, e.g., Oppenheimer
(1958, p. 319) and Davis (1974, p. 413).
able to get a temporary injunction prohibiting cloud seeding for hail
suppression. However, Auvil was unable to obtain a permanent injunction, because
he was unable to prove that the cloud seeding had caused a flood.
Texas 1958-59Southwest Weather Research, Inc. v.
Duncan, 319 S.W.2d 940 (Tex.App. 1958), aff'd sub nom. Southwest Weather
Research v. Jones, 327 S.W.2d 417 (Tex. 1959).
Research was a commercial cloud seeding company that was attempting to suppress
hail for the benefit of farmers in counties east of Jeff Davis County.
A group of ranchers in Jeff Davis County noticed that the cloud
seeding airplanes that were dispensing AgI above their land were causing local
clouds to dissipate, thus allegedly decreasing rainfall on the ranchers land.
The ranchers applied for a permanent injunction against the cloud seeders.
Before a hearing could be held on the permanent injunction, the judge granted a
temporary injunction, in order to preserve the status quo ante. The
issuance of this temporary injunction caused the reported appeal to the Texas
Court of Civil Appeals and then to the Texas Supreme Court, both of which
affirmed the issuance of the temporary injunction.
The opinions note
that the experts for the plaintiffs and defendant disagreed about whether cloud
seeding could cause a decrease in rainfall, although there was agreement that
"unimportant clouds with no rain potential could be dissipated."
319 S.W.2d at 942.
The Texas Court of Civil Appeals held:
- ... the landowner is entitled to such precipitation as Nature deigns to
bestow. We believe that the landowner is entitled, therefore and thereby, to
such rainfall as may come from clouds over his own property that Nature, in
her caprice, may provide. It follows, therefore, that this enjoyment of[,] or
entitlement to[,] the benefits of Nature should be protected by the courts if
interfered with improperly and unlawfully. .... We do not mean to say or imply
at this time[,] or under conditions present in this particular case[,] that
the landowner has a right to prevent or control weather modification over land
not his own. We do not pass upon that point here, and we do not intend any
implication to that effect.
- 319 S.W.2d at 945. Duplicated in a companion case, Southwest Weather
Research v. Rounsaville, 320 S.W.2d 211, 216 (Tex.App. 1958),
aff'd, 327 S.W.2d 417 (Tex. 1959).
This case appears to
be the only cloud seeding case in the USA in which the plaintiffs won. The later
hearing is unreported, so it is not known whether the permanent
injunction was granted. At the time of this case, there were neither state nor
federal statutes or regulations on cloud seeding.
I note that several
authors of law review articles appear to have missed the fact that Southwest
Weather Research is a request for an injunction to prohibit future harm,
not a tort case involving liability for past harm. Thus, Southwest
Weather Research teaches us nothing about negligence and little about
Nebraska 1960Summerville v. North Platte Valley Weather
Control District, 101 N.W.2d 748 (Neb. 1960).
A Nebraska state
statute, enacted in 1957, allowed landowners to create a weather control
district (which was a private corporation), and then vote on weather
modification projects. Summerville, the plaintiff, lived outside of the
district, but he owned property within the district. Summerville filed
litigation challenging the constitutionality of the state statute, because he
was affected by the decisions of the weather control district, but he had no
opportunity to be heard. Both the trial court and the Nebraska Supreme Court
found that the state statute was unconstitutional.
The opinion of the
Nebraska Supreme Court is remarkable in that it says absolutely nothing about
either weather modification or a landowner's rights to water from clouds. The
Court decided the statute was unconstitutional because the statute had the same
defects as an earlier statute that had been declared unconstitutional in the
I am surprised that this case has apparently inspired no
comment in law reviews. Similar cases could be brought in federal court under
the Fifth Amendment to the U.S. Constitution by a resident of
state X, challenging weather control activities in state Y that
affects land in state X.
California 1964Adams v. California, Nr. 10112
(Superior Court, Sutter County, Calif. 6 April 1964).
an unreported case that has been mentioned briefly in several law review
articles. See, e.g., Davis (1974, p. 413). The case is discussed in
detail by Morris (1968) and Mann (1968).
There were a total of
170 plaintiffs who alleged that cloud seeding increased the flow of water
in a river that caused a levee to break at midnight on
23 December 1955, which flooded their property.
(Morris, 1968, pp. 165-167) In this flood in Yuba City,
37 people died and "467 homes were totally destroyed and 5745 homes
damaged." (Mann, 1968, p. 691) These plaintiffs initially sued:
- the cloud seeder, North American Weather Consultants;
- the company that hired the cloud seeder, Pacific Gas and Electric Company
- the state of California, who operated the levee that broke; and
- fifty unknown defendants, who would be identified
Plaintiffs asserted two causes of action against the cloud
seeder: (1) "negligent maintenance and operation" of the AgI generators and (2)
cloud seeding was an ultrahazardous activity, which justified imposition of
liability without needing to prove negligence.
(Mann, 1968, p. 695)
Mann (1968, p. 692) notes in passing
that, despite a statutory requirement for public notice of all cloud seeding,
none of the plaintiffs were aware of the cloud seeding operation. The
attorney for the plaintiffs "almost inadvertently learned of the cloud seeding"
at a lunch conversation, about one year after the flood.
(Mann, 1968, p. 694)
Plaintiffs originally sued in a
California state court, the California attorney general removed the case to
federal court, and the judge in the federal court remanded the case to state
court. Adams v. California, 176 F.Supp. 456
There are two reasons why this trial did not
resolve whether or not the cloud seeding had contributed to the flood:
- Plaintiffs' attorney hired a meteorologist as an expert witness just a few
months before the trial began (despite approximately five years of preparation
by the attorney) and that expert wished to present a theory that had been
mentioned in neither the pleadings nor discovery.
(Mann, 1968, pp. 696, 701-02) Such late changes in the
theory of the case is basically trial by ambush and the judge properly granted
the defense motion to prevent such testimony. Because of poor preparation by
the plaintiff's attorney, not all of the relevant facts and opinions were
presented at trial.
- During the trial, PG&E paid plaintiffs' attorney in return for his
agreement not to appeal a possible verdict favoring either PG&E or the
cloud seeder. After this agreement, plaintiffs' attorney concentrated on suing
the state of California and apparently avoided cross-examination of witnesses
presented by the defendants on cloud seeding issues.
(Mann, 1968, p. 708)
The best reason why the cloud
seeding did not contribute to the flood was that PG&E halted the AgI release
three or four days before the levees broke.
(Mann, 1968, pp. 690, 694) PG&E's attorney argued that
any extra water from this cloud seeding passed by Yuba City one day before
the levees broke. (Mann, 1968, p. 705) However, these reasons are
not entirely convincing to me. We do not know if cloud seeding contributed to
this flood, for the two reasons in the indented list in the previous paragraph.
After 26 days of hearings on pretrial motions and then an almost
five-month trial, the court held:
- Plaintiffs may not recover against the PG&E or North American Weather
Consultants as they have failed in their burden of proof. The court finds that
neither the PG&E nor North American Weather Consultants produced any
significant increase in rainfall or snowfall outside of the Lake Almanor water
shed. The effects of cloud seeding were limited to the pre-determined target
area which drains only into Lake Almanor. Lake Almanor never spilled at any
time before or during the flood; and accordingly, any increase produced by
cloud seeding was successfully impounded by that PG&E lake.
breaking of the levees was neither proximately caused nor contributed to
either by the maintenance or by the operation of the artificial rain making
equipment of any defendant in this lawsuit.
- Judge John P. MacMurray, Adams v. California, Nr. 10112
(Superior Court, Sutter County, Calif. 6 April 1964), quoted in both
(Morris, 1968, pp. 182-83) and (Mann, 1968, p. 708).
losing against both PG&E and the cloud seeder, plaintiffs won against the
state of California, because of negligent design, construction, or maintenance
of the levees. (Mann, 1968, p. 709) Rather than have a trial on
damages, the State of California agreed to pay plaintiffs a total of
US$ 6,300,000, which was less than half of what plaintiffs had initially
requested. (Mann, 1968, p. 709) Incidentally, the California
Supreme Court has ended sovereign immunity in California a few years before the
Adams trial began. If sovereign immunity had existed, then plaintiffs
could not have won against California.
The attorney for PG&E
estimated that if cloud seeding had increased the rainfall by 15%, then
the cloud seeding contributed an extra "572 acre feet" (i.e.,
7 × 105 m3) of water upstream from the
levee, which the attorney argued was a "minuscule amount" and "could not have
contributed in any significant degree to the breaking of the levees."
(Morris, 1968, pp. 180-81;
Mann, 1968 p. 705).
no jury in this caseAttorneys involved in the case
initially estimated that trial of this case would require between 12 and
18 months of court time, mostly because of the evidence of damage by
170 plaintiffs. (Morris, 1968, p. 170-71) Because of the
anticipated extraordinary length of this trial, it was difficult to find a judge
who would hear this case. The case was tried in Sutter County, which had
only 12,000 registered voters who could be asked to serve on a jury. After
inquiries about possible bias and availability for a year-long trial, the jury
pool was reduced to 120 people. (Morris, 1968, pp. 172-73;
Mann, 1968, p. 699) The attorney for PG&E candidly
- Of the 400 potential jurors, only 120 agreed that they would serve for one
year. All but 10 of them were women, and those 110 women had generally a
background as a grocery store clerk, or a packinghouse worker. Both sides,
after spending literally years in preparing technical testimony, were somewhat
discouraged with the idea of having to present this information to a level of
women in their 60s who had an inadequate scientific knowledge to properly
follow the testimony.
- Morris, 1968, p. 173.
- As an aside, I note that most litigators in the USA express their
belief in the wisdom of juries, without any evidence to support that
belief, and in the face of the obvious inability of jurors who have no
education in science and mathematics to understand scientific evidence. Even
worse, jurors are called upon to evaluate conflicting expert opinions, which
is much more difficult than understanding the basis for each opinion. If
doctoral-level scientists can not agree on conclusions, what hope is there for
people on the jury (some of whom are probably high-school dropouts and none of
whom have taken even introductory classes in calculus and physics) to analyze
and evaluate such expert testimony? While I understand and agree with the
above-quoted statement of Attorney Morris, I also wish to reject his dim
opinion of stupid old women. The men in Sutter County,
California would be equally unable to understand and to evaluate scientific
evidence. The problem is that most jurors are ignorant of science and
mathematics, not that jurors are women.
the plaintiffs were reluctant to pay approximately US$ 36,000 in jurors'
fees (i.e., a modest US$ 10/day, for a ten-month trial of
20 days/month, for a total of 18 jurors [12 jurors and
6 alternate jurors]).
For these reasons, attorneys for both
plaintiff and defendant agreed to try the case without a jury.
(Morris, 1968, p. 173)
Pennsylvania 1968Pennsylvania Natural Weather
Association v. Blue Ridge Weather Modification Association,
44 Pa. D. & C.2d 749, 1968 WL 6708
The plaintiff, Pennsylvania Natural Weather
Association, was a group of property owners in Fulton County, Pennsylvania.
The defendant, Blue Ridge Weather Modification Association, was a commercial
cloud seeding company that had attempted in 1963 and 1964 to suppress hail in
the states of Maryland, West Virginia, and Virginia, in addition to
Franklin County, Pennsylvania. Franklin County is adjacent to
Fulton County, where the plaintiffs lived.
There had been a "severe
drought" in 1963, 1964, and 1965 in the northeastern USA, including
Fulton County. Plaintiffs sought an injunction preventing defendants from
seeding clouds. The legal issue before the court was
- ... the question of whether or not a landowner outside of the "target
area" is entitled to weather in its natural form, even though defendants'
activities were not intended to, and perhaps did not, in fact, affect the
amount of rainfall Fulton County received or did not receive. To state it
another way, does a landowner have a right to weather unmodified anywhere?
- 44 Pa. D. & C. at 752, 1968 WL 6708 at *2.
The court denied
plaintiff's request for an injunction, because of two reasons:
- Plaintiffs had not proven that they were harmed by the cloud seeding. For
example, there was a drought in 1965, but defendant could not possibly
have caused the drought in 1965, because defendant did no cloud seeding in
that year. The drought in 1963 began before the defendants began their cloud
seeding program. Plaintiffs had not proven that there was a "threat of
immediate and irreparable harm", which is one of the conditions for granting
an injunction. 44 Pa. D. & C. at 763-64,
1968 WL 6708 at *9.
- There was an adequate remedy at law, which barred the court from granting
the equitable remedy of an injunction. After the plaintiff filed this
litigation, the Pennsylvania legislature in 1965 enacted a statute regulating
cloud seeding. That statute specifically forbade weather modification
activities in any county "where the county commissioners enact a resolution
stating that such actions are detrimental to the welfare of the country." In
1967, the Pennsylvania legislature repealed that statute and enacted a new
statute that "specifically provides for damage compensation to property
owners" who are harmed by weather modification activities in Pennsylvania.
These statutes made the case moot.
44 Pa. D. & C. at 762-64,
1968 WL 6708 at *9-*10.
Because this case was
decided on grounds of "no irreparable harm" and "adequate remedy at law", the
court's opinions about the law of cloud seeding should be regarded as
obiter dicta. Moreover, this opinion was issued by a trial court,
which has no precedential value, not even in Pennsylvania. Nonetheless, the
court's opinions are quoted here, because such opinions are sparse, so any
judicial opinion (even an incidental remark) is significant:
- It seems to us that one of the elements of land in its "natural condition"
must be weather in its natural form, including all forms of natural
precipitation. .... [A landowner] does not assume the risk of weather
modification activities by neighbors.
- 44 Pa. D. & C. at 756, 1968 WL 6708 at *5.
- We hold specifically that every landowner has a property right in the
clouds and the water in them. No individual has the right to determine for
himself what his needs are and produce those needs by artifical means to the
prejudice and detriment of his neighbors. However, we feel that this cannot be
an unqualified right. .... ... cloud seeding has been used[,] and will
continue to be used[,] to produce rain to relieve the water shortage in our
urban areas. We feel then that weather modification activities undertaken in
the public interest, as opposed to private interests, and under the direction
and control of governmental authority should and must be permitted.
- 44 Pa. D. & C. at 759-60, 1968 WL 6708 at *7.
- Moisture in the clouds is common property belonging to everyone who will
benefit from what occurs naturally in the clouds. Every owner of land has a
property right in the moisture in the clouds and the right to receive that
moisture in its natural form subject to such weather modification activities
as shall be carried out by governmental authorities in the public, as opposed
to private, interest.
- 44 Pa. D. & C. at 763, 1968 WL 6708 at *9 (Conclusions of Law Nrs. 1
There is no further opinion in the Westlaw database for
Montana 1974Montana Wilderness Association v.
Hodel, 380 F.Supp. 879 (D.Mont. 1974).
Administration (BPA), an agency of the federal government, proposed to do cloud
seeding in a wilderness area, to increase the volume of water in a river
that was used for hydroelectric power. There is a federal statute that protects
the "natural condition" of wilderness areas from interference by man.
Plaintiffs were concerned that the proposed cloud seeding would harm or alter
the wilderness area. Plaintiffs filed litigation in federal court, asking the
court for declaratory judgment and an injunction prohibiting planned cloud
seeding. However, five days after plaintiffs filed this lawsuit, the BPA
"cancelled a contract which had been granted to North American Weather
Consultants" for cloud seeding. 380 F.Supp. at 880. In a
terse opinion, the judge refused to hear the case, because the case was moot:
the BPA had already decided not to seed clouds. Because there were no further
cloud seeding proposals in the next several years, Davis
(1977, p. 48, n. 142) commented: "It would appear that the
plaintiffs won their point without the need to go to trial."
South Dakota 1977Lunsford v. U.S., 418 F.Supp. 1045
(D.S.Dak. 1976), aff'd, 570 F.2d 221 (8thCir. 1977).
was a flood in Rapid City, South Dakota on 9 June 1972 that killed
283 people and caused extensive property damage. Plaintiffs alleged that
the flood was caused by an experimental cloud seeding program operated by the
South Dakota School of Mines and Technology, under contract to the
The court opinion considers only some preliminary,
technical issues in law that do not involve the merits of this case:
The trial court's opinion, which was reported at
418 F.Supp. 1045, mentions neither "cloud seeding" nor "weather
modification", but there is a terse mention in the appellate court's recitation
of the facts of the case.
- Whether the plaintiffs can maintain a class action, on behalf of all of
the victims of this flood.
- Whether the plaintiffs need to exhaust their administrative claims before
- Whether the U.S. Government was immune under 33 U.S.C. § 702c, which
provides for immunity for floods. That statute was enacted in the context of
flood control (e.g., dams, dikes, and levees) legislation in the year 1928 and
it is not clear if the statute also applied to floods caused by cloud
There is no further opinion in the Westlaw
database for this case.
North Dakota 1981Saba v. Counties of Barnes ...,
307 N.W.2d 590 (N.D. 1981).
Plaintiffs alleged that negligent cloud
seeding by a private company, Weather Modification, Inc., caused heavy rain in
Bismark, North Dakota on 31 July 1975 that damaged plaintiffs'
Plaintiffs originally sued the city of Bismark, alleging
"failure to properly maintain its sewer system." The city answered the original
complaint by asserting that "the torrential rain was an act of God." Plaintiffs
then amended their Complaint to delete the defendant city of Bismark, to add as
new defendants the cloud seeding company and nine counties that had hired the
cloud-seeding company, and to proceed on a new theory of negligent cloud
seeding. Although there were only two plaintiffs with known claims for damages,
plaintiffs' amended Complaint attempted to proceed as a class action, on behalf
of all potential plaintiffs. Id. at 596.
court refused to certify the class action and the South Dakota Supreme Court
affirmed. The opinion of the South Dakota Supreme Court is limited to the
possibility of a class action and does not reach the merits of the negligent
cloud seeding claim, which had not yet been heard by the trial court.
The Supreme Court of North Dakota coldly rejected plaintiffs' attorney
request for certification of the class action:
- We agree with the plaintiffs that one of the reasons for class-action
status is to permit a sharing of the expenses of litigation.
[citation omitted] However, we cannot determine that the class-action
rule was intended to permit the plaintiffs to obtain class-action status in
order to permit them to solicit additional plaintiffs who might be willing to
share the costs of exploring a novel theory of
Plaintiffs argue that they do not have the
financial resources to sustain such a suit in their individual capacities, and
that may well be the situation. However, we do not believe the class-action
rule was intended primarily as a vehicle by which parties whose alleged damage
exceeds the estimated costs of litigation but who do not have the financial
resources to sustain the costs of litigation are enabled to finance their
claims, although one of the benefits to parties of class-action status is a
sharing of the litigation expenses.
- Saba, at 596.
There is no further opinion in the Westlaw
database for this case.
California 1987-1990First English Evangelical Lutheran
Church of Glendale v. County of Los Angeles, 482 U.S. 304 (1987),
on remand, 258 Cal.Rptr. 893 (Calif.App. 1989),
cert. denied, 493 U.S. 1056 (1990).
Church owned five buildings situated on 21 acres of land in a canyon in
Palmdale, California. On 9-10 February 1978, there was a total of
28 cm of rain, and the ensuing flood in the canyon destroyed the buildings.
Following that flood, the County of Los Angeles enacted a temporary ordinance
that prohibited construction of any buildings in the canyon. Because the Church
could not rebuild in the canyon for 2½ years, that ordinance effectively
diminished the value of the Church's land.
The Church then sued the
County, alleging two causes of action:
- an inverse condemnation action, seeking compensation for the County's
taking of the land, contrary to article I, § 9 of the California
Constitution. (Similar rights are contained in the Fifth Amendment to the
- tort liability for cloud seeding conducted by the County's Flood Control
The trial court granted the County's motion "for
judgment on the pleadings on the second cause of action in tort and inverse
condemnation based on cloud seeding". 258 Cal.Rptr. at 895. That
terse remark is the only information in the published opinions of the California
courts on this important matter!
A trial was held on damages for the
County's alleged taking of the land, and "at the close of plaintiff's evidence
on liability, the court granted defendants' motion for nonsuit."
Id. at 896.
The California Court of Appeal affirmed in
an unpublished opinion, and the California Supreme Court refused to review the
case. The Church then appealed to the U.S. Supreme Court, which
rendered an opinion. The case then returned to the California Court of Appeal,
which held that the County's temporary ordinance "substantially advances the
highest possible public interest – the prevention of death and injury", so the
Church's "complaint does not state a valid claim for a compensable taking."
Id. at 905. The case was then remanded to the trial court for
"further proceedings ... as to the cause of action for inverse condemnation
based on cloud seeding." Id. at 907. There is no further
opinion in the Westlaw database for this case.
Incidentally, there has
been a suggestion that the California Court of Appeals,
258 Cal.Rptr. 893, misunderstood the U.S. Supreme Court's opinion
in the same case. McDougal v. County of Imperial, 942 F.2d 668,
676 (9thCir. 1991).
conclusions about case law in the USADespite the potential
immense economic importance of cloud seeding, and the important legal issues
about who has property rights in clouds that might provide rain:
During the past fifty
years, the courts in the USA have not resolved any of these important issues. A
law professor said that the above cases are "sparse and contradictory".
Davis (1974 , p. 433) Slutsky in New York
absolutely rejected a landowner's rights in water from clouds; Southwest
Weather Research in Texas accepted a landowner's rights in water from clouds
and found that the landowner might be harmed by future cloud seeding; while
Pennsylvania Natural Weather Assoc. accepted a landowner's rights in
water from the cloud with some conditions, but found that the plaintiffs had not
proved they would be harmed by future cloud seeding.
- None of these reported judicial opinions discuss negligent cloud
- Few of these reported opinions discuss property rights of
landowners to rain from the clouds that are either above their land or upwind
from their land.
- Since 1980, there have been only two reported cases on the topic of
either: (a) injunctions prohibiting cloud seeding or (b) liability for alleged
negligent cloud seeding. Neither of those two cases discussed the merits
of the cloud seeding issue.
- Apparently no plaintiff has alleged a deprivation of precipitation in a
tort case involving cloud seeding in the USA.
There are a number
of reasons why judges have neither decided nor explained the law in this new
- Litigation is expensive and slow. Plaintiffs often exhaust their financial
resources before all of the possible appeals can be heard, which forces a
premature end to an interesting case.
- In other cases, subsequent events (e.g., end of a drought) may make it
unimportant to plaintiffs to resolve all of the issues in their original
- Sometimes defendants offer a substantial financial settlement to
plaintiffs, in order to avoid the possibility of a reported judicial opinion
that could serve as unfavorable precedent for the defendants in future cases.
Plaintiffs accept the offer and the case ends, without any judicial opinion on
the merits. (I do not know that this has happened in any weather modification
case, but it is common in some other areas of law.)
- The job of judges is only to decide the facts or law necessary to
dispose of the particular case before them, not to write an essay about
novel legal issues that are unnecessary to the disposition of the
current case. When a judge does write about unnecessary issues, the judge's
comments are obiter dicta, which are not precedent for
In particular, it is rare for a judge in an appellate
court to give guidance to the judge in the trial court on matters
not specifically mentioned in the appeal. For example, as
mentioned in several cases above, an interlocutory appeal on certifying a
class action only decided the desirability of the class action, without
any discussion of the merits of the case, even if the appellate judge should
know that the trial judge will need guidance in dealing with novel,
unprecedented legal issues in a future trial on the merits. In other
words, appellate judges exist to correct mistakes already made by lower court,
not to help avoid mistakes that might be made by the lower court in a
future trial in the case.
This limited role of judges is contrasted
with the job of the scientist who writes a paper or book for publication (or
with a law professor who writes an article in a law review), where the author
discusses a subject thoroughly.
- Most judges are burdened by a very large number of cases, so they do not
have adequate time to write a careful, scholarly discussion of novel issues
that would be worthy of publication.
- When a judge makes a decision on any important new topic, it is almost
certain that a substantial number of people (including the losing party in
litigation and his/her supporters) will react with anger and scorn, simply
because they disagree with the judge's decision. The angry public reaction
discourages judges from saying more than the minimum amount necessary to
dispose of a case.
- And, finally, because most attorneys and judges went through high school
and college taking the minimum number of classes (and the easiest classes) in
science and mathematics, they are now poorly prepared to handle cases
involving scientific evidence (e.g., about cloud seeding). There is a
natural tendency for judges, like everyone else, to avoid what they do not
In one of the earliest reported cases involving cloud
seeding, the Texas Supreme Court twice mentioned "complicated scientific
problems". 327 S.W.2d at 421. To me, as a scientist, such
problems are no more complicated than in many other areas of scientific or
I remarked above on the angry public reaction
to a judge's decision. Let me compare and contrast the situation in science to
that in law. Research scientists become famous for writing landmark papers in
scholarly journals, and many scientists would eagerly seize the opportunity to
write a publication on an important new topic. It is rare for a scientific
publication to cause an angry reaction among many readers. Indeed, most
scientific accomplishments are ignored by journalists, politicians, and the
public. In contrast, meteorologists who are involved in public hearings on
cloud seedings are often exposed to an angry, political situation that is unlike
anything in conventional scientific research. And, unlike the situation
in science, opinions expressed at hearings on cloud seeding may be based on
superstition, emotions (e.g., fear or anger), politics (e.g., having their
personal concerns ignored or rejected by a bureaucrat whom they neither trust
nor respect), religion (e.g., it is immoral to modify God's weather), ....
Farmers and ranchers opposed to cloud seeding have used violence and
sabotage against both cloud seeders and those sponsoring cloud seeders
(Howell, 1965, p. 329; Carter, 1973, p. 1349).
4. General PrinciplesAs discussed
above, judges have neither decided nor explained tort liability for negligent or
wrongful cloud seeding. However, the general principles of tort liability are
well established in many other areas (e.g., negligence, medical malpractice,
etc.) and these general principles would probably be used by judges to decide
cases involving negligent or wrongful weather modification.
of Tort Liability
several broad kinds of torts:
- strict-liability torts Plaintiff only needs to prove that
defendant caused plaintiff's injury, without also needing to prove wrongful or
negligent conduct by plaintiff. When plaintiff wins a strict-liability tort
case, the court orders defendant to compensate plaintiff, as a way of
redistributing wealth (i.e., a large corporation or insurance company pays an
injured individual, as part of the cost of doing business), not as
compensation for a wrong. There are only a few kinds of strict-liability
torts, of which "abnormally dangerous activities" might be relevant to
- fault-based torts in which the injury to plaintiff was produced as
a result of some kind of negligent or wrongful act by the defendant. Essential
elements in proving these torts is showing that defendant owed a specific duty
of care to the plaintiff and that defendant breached his/her duty.
- trespass or nuisance, which require either intent, negligence, or
abnormally dangerous activity.
The plaintiff in a fault-based tort
case needs to prove each of the following four elements of a tort:
- duty, a standard of conduct, e.g., specify the appropriate care
that defendant should have used.
- breach of that duty, e.g., the defendant's conduct was
- injury, proof of the harm that the plaintiff suffered as a result
of defendant's act(s), or defendant's failure to act. If weather
modification causes an amount of rain that is only slightly different from the
average rainfall, I suggest below that there is
no injury to plaintiff.
- causation, proof that defendant caused the injury. It is
important to understand that, even if a cloud seeder was negligent, there is
no tort liability unless the cloud seeder can be proved to
have caused the harm to a plaintiff. In the context of weather modification
torts, the proof of causation has been so difficult that I discuss this topic
in a separate section below.
more general information on torts, see my general essay on that topic.
court accepts a strict-liability tort, the plaintiff can skip the proof of the
first two elements above: duty and breach of that duty. Superficially,
strict-liability torts appear to be easier to argue than fault-based torts.
However, unless strict-liability for weather modification is established in a
statute, the plaintiff will need to convince the judge that strict liability
applies, which may be more difficult than proving negligence or nuisance in a
possible strict-liability tort"Abnormally dangerous
activities" are defined in Restatement Second of Torts, § 520 (1977).
Legislatures in three states have enacted statutes that specify cloud
seeding is not an abnormally dangerous activity, thus strict liability
can not apply to cloud seeders in those states:
On the other hand, a
Pennsylvania statute appears to establish strict liability for any drought or
"heavy downpours" that the state weather modification board finds to have been
caused by weather modification.
16 Pennsylvania Statutes § 1114 (1968).
- North Dakota § 61-04.1-37(1) (1981);
- Texas Art. 165c, § 1.72(a) (2001) This Texas statute
was first enacted in 1966. (Davis, 1974, p. 430);
- Wisconsin § 93.35(14)(a) (1981).
In other states, it is an unresolved question whether
judges will accept strict-liability torts against cloud seeders.
possible fault-based tortsPlaintiffs have several possible
fault-based tort actions against cloud seeders:
- negligence per se Two state statutes proclaim that failure
of a cloud seeder to follow the licensing requirements or state regulations is
negligence per se:
In these states, if the
plaintiff can prove that the cloud seeder violated state law or regulations,
then, as a matter of law, negligence is automatically proved.
- Colorado § 36-20-123(2)(a) (1972);
- Wisconsin § 93.35(14)(d) (1981).
absence of such a statute, there is a common law duty to obey statutes and
regulations that are designed to prevent harm. Restatement (Second) of Torts,
§§ 285(a), 286, 288B(1) (1965).
- negligence The cloud seeder is held to a standard of care of
a competent, professional meteorologist who was engaging in cloud seeding, who
takes reasonable care to avoid foreseeable and unreasonable risks.
(Note that the standard is not an average meteorologist, because
that would make half of the cloud seeders negligent!) The standard of
care can be established in several ways:
However, conduct that conforms with all relevant
statutes, regulations, standards, and customs in the trade might still be
negligent, if the conduct presents an unreasonable risk of harm.
- a statute or government regulation that is intended to protect the
public safety. Restatement Second of Torts § 286 (1965).
- a standard or code of conduct adopted by a professional society.
- testimony of another meteorologist who has experience in weather
commercial cloud seeder who advertises his/her services as unusually competent
(e.g., having tens of years of experience, employing scientists who have
earned a Ph.D. in meteorology, etc.) can properly be held to a higher standard
than a typical cloud seeder. Restatement (Second) of Torts § 289(b) and
§ 299A (1965). This is an area familiar to attorneys who concentrate in
tort litigation: advertising can come back to haunt a defendant.
example of how a negligence claim might arise, Jones (1991, p. 1177)
gave an example of a cloud seeder who decides to seed on a day for which heavy
rains are forecast, therefore enhancing heavy rain to a catastrophic
condition. I agree that it is a good example of negligence, but the
example contains two hidden assumptions: (1) that forecasts of the amount of
rain are usually accurate, and (2) that cloud seeding usually enhances
(not decreases) the amount of rain. In an actual case,
plaintiffs would need to prove those assumptions were true, which could be a
trespass or nuisance
- trespass is the invasion of either a person or a thing upon the
land owned by another person. Restatement Second Torts
§§ 158, 165 (1965).
Typical cloud seeding releases tens
or hundreds of grams of nontoxic AgI into a cloud or the air. Some legal
commentators (e.g., Davis, 1974, p. 430; Ferdon, 1984,
pp. 688-89; Jones, 1991, pp. 1174-75) have suggested that
this release of AgI might be considered a trespass on the plaintiff's
Several state statutes declare that weather modification is
not a trespass:
- Colorado § 36-20-123(1) (1972);
- North Dakota § 61-04.1-37(2) (1981);
- Utah § 73-15-7 (1973) (no presumption of trespass);
- Wisconsin § 93.35(14)(b) (1981).
I believe that a
trespass claim for the AgI itself is a bit specious:
- the quantity of AgI is trivial.
- the AgI occurs as microscopic crystals, which are real, but not
perceptible to the human senses.
- the AgI itself is essentially harmless (Standler and Vonnegut, 1972),
unlike a noxious pollutant.
- most of the AgI is contained in either the air, cloud, or rainwater,
none of which may touch the land of a plaintiff who alleges that cloud
seeding deprived him/her of rain.
Instead of focusing on the AgI
itself, I suggest focusing on the effect of the AgI in either: (a)
diminishing rainfall that would have otherwise occurred or (b) causing
excessive rainfall (e.g., a flood). In fact, the first law review article
written on the subject of weather modification said:
- If the cloud seeder intentionally causes rain to fall on the plaintiff's
land, a trespass is committed as clearly as if he had turned a stream of
water from a hose on plaintiff's house. Where the defendant does not intend
to cause rainfall on the plaintiff's land, the plaintiff would be required
to show that the defendant was either negligent or engaged in an
- anonymous, 1949, p. 532.
- "Ultrahazardous activity" was the nomenclature in the First Restatement
of Torts for what the Second Restatement in 1977 called an "abnormally
It is well-established law that surface
water entering plaintiff's land can be a trespass. For example, consider
the following cases:
- Red Lake Hunting & Fishing Club v. Burleson, 219 S.W.2d 115
- Levene v. City of Salem, 229 P.2d 255 (Or. 1951);
- Yenchko v. Grontkowski, 122 A.2d 705 (Penn. 1956);
- Corrington v. Kalicak, 319 S.W.2d 888 (Mo.Ct.App. 1959);
- Herro v. Board of County Road Commissioners, 118 N.W.2d 271
- Bell v. Union Electric Co., 367 S.W.2d 812 (Mo.Ct.App. 1963);
- Union Pacific Railroad v. Vale, Oregon Irrigation Dist., 253
F.Supp. 251 (D.Or. 1966);
- First Kingston Corp. v. Thompson, 152 S.E.2d 837 (Ga. 1967);
- Senn v. Bunick, 594 P.2d 837 (Or.App. 1979);
- Ratliff Co. v Henley, 405 So.2d 141 (Ala. 1981);
- Mack v. Edens, 412 S.E.2d 431 (S.Car.App. 1991);
- U.S. v. Imperial Irrigation Dist., 799 F.Supp. 1052 (S.D.Calif.
- Easterling v. Awtrey Building Corp., 770 So.2d 606 (Ala. 1999);
- Canton v. Graniteville Fire Dist. Nr. 4, 762 A.2d 808 (Vt. 2000);
- Dougan v. Rossville Drainage Dist., 15 P.3d 338 (Kan. 2000);
- Sumitomo Corp. v. Deal, 569 S.E.2d 608 (Ga.App. 2002).
Liability for trespass requires plaintiff to prove either:
intent, negligence, or "abnormally dangerous activity" by the defendant.
Restatement Second of Torts, § 166 (1965). It is an unanswered
question whether a cloud seeder's intent to cause rain would justify trespass
liability for a consequential flood.
- private nuisance "A private nuisance is a nontrespassory
invasion of another's interest in the private use and enjoyment of land."
Restatement Second of Torts, § 821D (1979). A private nuisance requires
an invasion that is either:
Id. § 822. Several law review
notes (anonymous, 1960, pp.308-09; Ferdon, 1984, p. 690-91;
Jones, 1991, p. 1175-77) have discussed how nuisance might be applied to
- "intentional and unreasonable" or
- unintentional and either:
- negligent conduct,
- reckless conduct, or
- abnormally dangerous
Two state statutes declare that weather modification is
neither a public nor a private nuisance:
- Colorado § 36-20-123(1) (1972);
- Utah § 73-15-7 (1973)
(no presumption of nuisance).
The famous torts
textbook by Prosser and Keeton gives three possibilities for enjoining
- (1) if defendant's activity is "reasonable" and if that activity
causes an "insubstantial" inference with the use of plaintiff's land, then
neither an injunctive nor a tort remedy is available.
- (2) if "defendant's activity is socially desirable" and "reasonable",
then the injunction is not granted, but plaintiff can sue in tort for damage
that plaintiff suffers if the effect of the defendant's acts is "substantial
... such as would be offensive or inconvenient to the normal person".
- (3) if defendant's "conduct at the time and place is unreasonable"
and if "the gravity of the harm outweighs the utility of the
[defendant's] conduct", then the injunction is granted.
- William L. Prosser, W. Page Keeton, et al., Prosser and Keeton on the
Law of Torts, 5th ed., West Publishing, 1984,
at §§ 87, 88A, at pages 620, 631 of the
summary of tortsThe reader is cautioned that the above
possible torts are all hypothetical in the context of weather modification:
there has apparently been no actual case, anywhere in the USA, in which
plaintiffs in a weather modification case have won by using such a tort theory.
Of the above torts, I suggest that plaintiff's attorneys consider
trespass and nuisance in the context of weather modification.
proof of causationRegardless of whether plaintiff proceeds
on a fault-based tort, or on a strict-liability tort, plaintiff must prove in
court that defendant's acts caused the harm to plaintiff. Articles in law
reviews and symposia agree that proof of causation is the most difficult
obstacle facing plaintiffs in weather modification cases:
- "a staggering burden". (Stark, 1957, p. 706)
- "Before the courts will award damages ... in weather modification cases,
they must be convinced ... that (1) the modification attempt did, in fact,
alter the weather and (2) the modification of the weather was, in fact, the
cause of the plaintiff's damage and that this damage would not have occurred
otherwise. Because of the nature of the weather modification problem, these
factors will be exceedingly difficult, if not impossible, to prove."
(Johnson, 1968, p. 85)
- "Failure to prove that the defendants' actions were the legal cause of
harm suffered by the plaintiffs has been the downfall of most persons seeking
judicial relief against weather modifiers."
(Davis, 1974, pp. 412-413)
- "Failure to demonstrate the linkage between conduct of the defendant and
harm to the plaintiff's property remains the major impediment in litigation
involving hail suppression and other types of cloud seeding."
(Davis, 1977, p. 40)
- "probably be a futile effort with his insurmountable proof problems."
(Kirby, 1978, p. 60).
- "With only one exception [i.e., Southwest Weather Research, which
was a request for an injunction, not a tort case], plaintiffs to date
have been unsuccessful in bearing that burden" of proving causation.
(Ferdon, 1984, p. 686) "... plaintiff's seemingly impossible
burden of proving causation ...." Id. at 698.
- "The primary reason plaintiffs have failed in court is that it is
difficult, if not impossible, to prove causation."
(Jones, 1991, p. 1169)
- An attorney wrote in 1978:
- Each storm system is individual, and it is impossible to ascertain the
effect of any modification effort for the very simple reason that a cloud
cannot be unmodified and modified at the same time.
- William A. Thomas (1978, p. 119).
- A law student, writing in 1984, commented that:
- Despite satellites, computers, and technical wizardry, it is impossible to
predict exactly how much rain will fall in a given area at a given time, even
under normal, unmodified conditions. .... Because it is
impossible to predict exactly how much precipitation a given cloud would
produce in the absence of seeding, it is equally impossible to measure the
effect of seeding.
- Ferdon (1984, p. 683-84).
In my opinion, both of these two
authors were wrong to declare the "impossibility" of such proof. Proof in tort
litigation does not need to be absolute, but only to convince the jurors that
the defendant caused the harm is more likely (i.e., probability greater than
50%) than the defendant did not cause the harm. Such a proof should be
technically possible. Nonetheless, past cases in the USA show that plaintiffs
have not been able to prove that cloud seeding caused his/her harm. There are
several reasons for this apparently insurmountable problem of proving causation:
- In cases during the 1950s and 1960s, scientific research had not yet
progressed to the point of being able to prove causation. Problems proving
causation in old cases does not necessarily imply that current cases will also
- Evidence that proves causation will involve atmospheric physics (e.g.,
thermodynamics of water vapor, liquid water, and ice) and statistical analyses
of cloud seeding experiments. Such evidence will be incomprehensible to jurors
and judges, because they are ignorant of both physics and statistics.
(Incidentally, this is a common problem in tort cases involving
science, technology, or medicine. In my opinion, courts in the USA have not
yet found a satisfactory way of handling scientific evidence. Indeed, courts
in the USA avoided evaluating scientific evidence until the landmark
June 1993 U.S. Supreme Court decision in Daubert.)
- Scientists who are experts in weather modification may be more sympathetic
to the defendant cloud seeder than to injured plaintiffs, so it may be
difficult for plaintiffs to find credible expert witnesses to testify on their
- Cloud seeding produces a small perturbation (e.g., perhaps 10% extra
rainfall as the result of cloud seeding) of a phenomena that has much larger
natural fluctuations. Without a complete understanding of the physical
processes in the cloud and measurement of all relevant parameters, one can not
accurately predict the effect of cloud seeding on a single cloud. Because we
lack this complete understanding and because we lack adequate data, we can
currently only know the effect of cloud seeding by statistical comparison of
large numbers of seeded and unseeded clouds. However, attorneys for the
defendant cloud seeder will likely object to statistical evidence and demand
only evidence that is restricted to the actual cloud(s) involved in the
In cases where plaintiff alleges that cloud seeding caused a
flood from one particular cloud, problems with proving causation prevent
plaintiff from succeeding in tort. The only way that I see for plaintiffs to
make such a proof is, at the time of the rain that causes the flooding, to
collect rainwater in special bottles that are free of metallic impurities, then
later (i.e., after a damage claim) have that rainwater analyzed in a chemical
laboratory that can detect concentrations of silver in rainwater as small as
0.01 nanograms/cm3. Collection of such evidence by flood victims
is impractical. However, it would be practical for technicians at a
government agency to collect such rain samples routinely during cloud seeding
programs. A government regulation or statute might specify the collection of
such samples, and the retention of the samples for, e.g., at least
two years after each rainfall.
In cases where plaintiff alleges
that cloud seeding caused a drought, there may be statistical evidence that may
be useful to plaintiff. Scientific research involving hundreds of clouds, half
of which were randomly chosen to be seeded, the other half of which remained in
a natural state, have provided statistical evidence of the effect of cloud
seeding. However, such evidence is very difficult to explain to juries,
attorneys, and judges, because of the sophisticated mathematics involved in the
inconsistent positionWilliam A. Thomas
(1978, p. 120) mentioned that commercial cloud seeders in the past
have been inconsistent in their statements. When advertising their services,
cloud seeders claim to be able to enhance rainfall. But when plaintiffs sue
them for causing excessive rainfall, the cloud seeder denies that the seeding
caused the excess rainfall. A similar observation was made by Stark (1957,
p. 707, n. 24).
of cloud seeders
The attorney defending a company that hired a
cloud seeder in Adams v. California was faced with the problem that his
client's own analysis showed that the cloud seeding caused a 20% increase
in rainfall. When plaintiffs who had been harmed by a flood allegedly caused by
the cloud seeding cited this 20% figure, defendant's attorney discredited
his own client's work by arguing that his client was ignorant of proper
(Morris, 1968, pp. 164, 176-77, 179;
Mann, 1968, pp. 705, 710)
- A science journalist noted:
- Weather modifiers are pleased to receive credit when the weather is
behaving as desired, but, should a destructive or unwanted storm bring a
lawsuit, they readily (and thus far successfully) take refuge in the absence
of scientific proof of causality.
- (Carter, 1973, p. 1348).
A skillful litigator for
plaintiffs, may be able to exploit this inconsistent position of cloud seeders,
to destroy the credibility of cloud seeders in a trial.
5. Need alternative to tort litigationFinally, I note that
the requirement to prove causation in tort litigation was (and may still be) an
insurmountable obstacle for plaintiffs. It is inequitable to modify
weather to benefit some people, but not compensate those who have been harmed by
the modified weather. If burdens of proof from traditional tort law (e.g., the
problem of proving causation) are insurmountable obstacles to such plaintiffs,
then legislatures (or judges) need to develop alternative ways of compensating
For example, the statutory law may evolve to specify
that only the state or federal governments could initiate weather
modification activities, although private cloud seeders might do the actual work
under contract to the government. Such an approach would recognize that weather
is part of the natural environment (also including land, water, and air) and any
attempt to modify the environment should be controlled or regulated by the
A governmental agency that contracted for the weather
modification could also compensate landowners who were harmed by the modified
weather. This agency could tax landowners who would benefit from increased
rainfall (e.g., a tax of a few cents/acre of land) and use that money
specifically to (a) pay for the weather modification and (b) compensate
landowners who were deprived of rainfall or who suffered a flood. Such an agency
could compensate injured landowners according to a formula in a regulation or
statute, without proving causation according to traditional tort law. This
agency would have many advantage over traditional tort law: reduced legal fees,
no delays in courts, and no requirements for proving causation that genuinely
injured plaintiffs can not meet.
In such an arrangement, the cloud
seeder would be an innocent agent of the landowners who received the enhanced
rainfall. Such a legal position would be analogous to
respondeat superior (i.e., ordering the employer, not the employee
personally, to compensate the victim for a harmful act within the scope of
employment). Unless the conduct of the cloud seeder was either negligent or
reckless, it seems inappropriate to me to hold the cloud seeder legally
responsible for modified weather that benefits some people and harms other
The amount of rainfall naturally
varies from year to year, so there is no injury to plaintiff if the actual
rainfall is slightly below the long-term average (i.e., the 50%tile)
amount. For that reason, perhaps the plaintiff in a drought case should be
compensated only for monetary loss resulting from the difference between the
25%tile rainfall (i.e., the amount that is exceeded in three out of four years
with unmodified weather) and the actual rainfall. This proposal helps prevent
the defendant from compensating plaintiff for effects of the variability of
naturally occurring weather, for which defendant is not responsible, and
for which plaintiff must assume the risk. My proposal for the 25%tile value as a
boundary was arbitrarily chosen, only for use as an example in this essay. The
boundary actually used should be determined by a legislative committee that
writes a statute that establishes the rules for compensating those who are
harmed by weather modification.
insuranceAlternatively, landowners could purchase
insurance against drought and floods. The insurance company would compensate
those harmed by either natural or modified weather, similar to no-fault
insurance for automobile accidents. In situations where the insurance company
had paid a large amount for claim(s) and the insurance company suspected
negligent or reckless conduct by cloud seeders, the insurance company could sue
the cloud seeders under the right of subrogation in the insurance contracts.
Such a use of insurance has several significant advantages for landowners over
- would also compensate landowners for harm from unusual
natural weather (a drought has the same effect on the landowner,
regardless of whether the drought is naturally occurring or the result of
- remove the need for landowners to prove that a cloud seeder caused the drought
- solve the problems associated with class action litigation by landowners
that was discussed above in the Lundsford and Saba cases.
- spread the costs of litigation over all who pay for insurance, instead of
concentrating the costs of litigation on plaintiff(s).
6. Support of Basic Scientific ResearchMany of the
problems with the law of weather modification are attributable to our lack of
basic scientific understanding of how clouds produce rain, and how cloud seeding
modifies processes in the cloud.
While the need for increased financial
support for basic scientific research is an important issue of public policy
that faces legislators, that issue is not, strictly speaking, part of the law of
cloud seeding. Therefore, I moved the discussion of financial support for
scientific research from an earlier version of this essay to a separate document, to shorten this
essay on the law of cloud seeding.
Only after the applicable
scientific principles are understood can we have a rational application of law
to weather modification, such as determining in tort litigation if a cloud
seeder caused a flood or drought, or determining if a cloud seeder was
negligent. Good laws and good regulations can not be based on possibilities and
conjectures. Scientific proof that a weather modification technique is both safe
and effective should occur before a government grants a permit for an
operational weather modification project that uses that technique.
7. Property Rights in WaterThis
essay has focused on injunctions prohibiting cloud seeding and tort liability
for cloud seeding (e.g., either causing a drought, causing a flood, or otherwise
interfering with the use of plaintiff's land) because those are the subject of
all of the past court cases in the USA on weather modification and
because I am interested in tort law and equitable remedies (e.g., injunctions).
from Cloud Seeding
However, there is another legal issue in weather modification that has
apparently been ignored by everyone, except one law professor,
Ray Jay Davis. This neglected legal issue is to answer the question of
who owns the right to use the extra water that is produced by cloud seeding.
In the western USA, there are attorneys who specialize in the complex
area of water rights, which is a subset of property law. Because I am not
personally knowledgeable about water rights law in the various states, I choose
to avoid summarizing those laws here.
When encountering new issues in
law, attorneys try to find an analogy to issues for which there is well settled
law. A law student suggested that clouds were analogous to wild ducks who flew
over the land. (Brooks, 1949, p. 119) A law professor later
suggested that clouds are "rivers flowing through our skies".
(Davis, 1968, p. 104)
unjust enrichment of nonpayers?One could envision this
issue arising in the context of a cloud seeder who is paid by farmer A to
increase the rainfall on A's land. Extra rain [also] falls on land owned by
farmer B; B's land is perhaps adjacent to A's land, or at least near A's land.
We recognize that B has received a benefit from the extra rainfall, for which B
paid nothing. From one point of view, B has been unjustly enriched. If a judge
accepts this unjust enrichment argument, who should B pay: the cloud seeder (who
caused the extra rain) or reimburse A for hiring the cloud seeder? The answer to
that question might depend on who owns the right to use the extra rainfall. In
defending himself, B might argue that he never requested the benefit: the extra
rain was an unsolicited gift to B. And B might also argue that any rain falling
on his land was his to use, an argument that is obviously correct prior to the
invention of cloud seeding technology, and might continue to be correct.
From the viewpoint of economics, B is a "free rider": B received a benefit
from which someone else paid the entire cost, including any potential liability
for negligence, etc. Without answering the interesting question about who owns
the right to use the extra water, the obvious solution to this kind of problem
(as well as many other potential problems) is to have the government regulate
all cloud seeding and to tax all landowners in the target area, so that
every potential beneficiary pays.
While experts on water rights law have
speculated about the legal rights of cloud seeders to use the extra water
that they produce (Davis, 1968, p. 112;
Beck, 2001, p. 3-22), it seems to me that there is a simpler
solution that requires no new law. After receiving a permit to modify
weather, the cloud seeder has a legal right to attempt to modify weather, but
the right to use any extra water belongs to the landowner on whose land the
extra precipitation falls. My proposal treats the cloud seeder by analogy to
many other professionals (e.g., investment advisers, surgeons, dentists,
engineers, etc.) who are paid for their services (i.e., making a "best effort"),
but any benefits and ordinary risks of those services belong to their
clients. However, the cloud seeder, like other professionals, remains
responsible for any negligence or recklessness in performing services.
deprivation downwindA more
complicated problem is that of the deprivation of rainfall downwind from where
cloud seeding has enhanced rainfall. The downwind atmosphere (clear air and
clouds together) obviously has less water content as a result of the greater
rainfall upwind, hours, or a day, earlier. If landowners have a
legal right to receive the naturally occurring rainfall, then downwind
landowners have been deprived of rainfall.
from cloud seeding?
From the viewpoint of
atmospheric physics, such concerns seem trivial. Clouds are not efficient at
producing rain or snow: most of the water (or ice) in a cloud does
not reach the ground during that one shower or snowstorm. Even after a
vigorous rain shower, thunderstorm, or blizzard, most of the original cloud
remains in the sky. A meteorologist explained for orographic clouds:
- In a typical precipitating cap cloud about 20 percent of the water vapor
in the upwind air mass (which we shall assume is cloud free) condenses. Of
this, about 20 percent falls out as precipitation. Therefore,
100 (0.20 × 0.20) = 4% of the water vapor is removed.
If cloud seeding increases the precipitation by 10 percent, then the
water vapor is depleted by an additional
100 (0.10 × 0.04) = 0.4%, a relatively small figure.
The argument is quite valid and has been used for many years to
explain that a rather trivial reduction in total water would occur in the area
downwind of a target area. ....
- Elliott, 1974, p. 61.
From this viewpoint, the
deprivation of rain suffered by downwind landowners is de minimis, a
harm that is too trifling to be compensated (i.e., De minimis non curat
lex.). Alternatively, the computation of the amount of damages will be
speculative, and thus too uncertain to permit a court to order compensation,
because the plaintiff is not likely to have data on the amount of water that was
wrongfully removed by cloud seeding that would have otherwise have fallen on
In a few days, some of the rainfall from previous
cloud seeding will have evaporated and contributed to a new cloud, thus renewing
the cycle of water in the atmosphere. The new cloud will be larger as a result
of the evaporation of the enhanced rainfall that was caused by previous cloud
seeding. I wonder if the legal concern about downwind deprivation of
rainfall would be better cast as a delay in downwind rain. If the delay
is only a few days, such harm would be de minimis.
(1968, p. 116) suggested that, to restore the deprivation, cloud seeders
also seed clouds downwind from the first target zone, but that remedy only
pushes an increased deprivation further downwind. Again, the obvious solution to
this kind of problem (as well as many other potential problems) is (1) to have
the government regulate all cloud seeding and (2) to have either a government
agency or private insurance compensate landowners for below average rainfall.
A leading treatise on water rights law in the USA says:
- Does intervention mean taking rain from someone else further down the
cloud drift? Scientists appear to say no, but lay persons do not believe
readily, and therefore the threat of litigation has to be considered.
- Beck, 2001, p. 3-12.
- This reaction by laymen is one of the most exasperating features of making
public policy about science or technology. Laymen will form a personal
opinion, even a strong belief, without any rational reasons to support their
opinion. On the other hand, scientists ideally form opinions after considering
all of the relevant facts and theories, including measurements and
8. ConclusionIt is clear that man already has the
technology to modify weather and that more effective technology can be designed.
However, we need scientific knowledge to understand how and when to use such
weather modification technology, so that intelligent choices can be made,
instead of guesswork. Civilization would immensely benefit if damage from
drought, floods, hurricanes, hail, tornadoes, etc. could be reduced. But before
we reap such practical benefits, we need much more basic scientific research.
Despite the potential immense economic importance of cloud seeding and
the existence of commercial cloud seeding technology since 1950, the courts in
the USA have not yet begun to resolve legal issues involving either
negligent cloud seeding or the rights of landowners to rain from the clouds that
are either above their land or upwind from their land.
After reading all
of the reported court cases in the USA on this topic, I conclude that states
need to create a government agency to compensate
people who have been harmed by weather modification, or, alternatively,
landowners need to purchase flood/drought insurance.
In my companion
essay, I conclude that the government should provide more long-term financial
support for basic scientific research.
9. BibliographyIn addition to the cases cited above, the following
articles in scientific or legal journals and books may be of interest. My
companion essay on the technology and history of cloud seeding contains
additional citations to
the scientific literature. Because this essay will be of interest mostly to
nonattorneys, I have used a standard academic citation format, instead of the
customary legal citation format.
anonymous, Note: "Who Owns the
Clouds?," Stanford Law Review, Vol. 1, pp. 43-63,
anonymous, Note: "Artificial Rainmaking,"
Stanford Law Review, Vol. 1, pp. 508-537, April 1949.
anonymous, Note: "Legal Remedies for 'Cloud-Seeding' Activities:
Nuisance or Trespass?," Duke Law Journal, Vol. 1960,
pp. 305-09, 1960.
Robert E. Beck, Waters and Water Rights,
Vol. 1, § 3.04, Lexis/Nexis, 2001.
Stanley Brooks, Comment:
"The Legal Aspects of Rainmaking," California Law Review, Vol. 37,
pp. 114-121, 1949.
Luther J. Carter, News Article, "Weather
Modification: Colorado Heeds Voters in Valley Dispute," Science,
Vol. 180, pp. 1347-1350, 29 June 1973.
Davis, "Special Problems of Liability and Water Resources Law," pp. 103-162, in
Howard J. Taubenfeld, editor, Weather Modification and The Law, Oceana
Ray Jay Davis, "State Regulation of Weather
Modification," Arizona Law Review, Vol. 12, pp. 35-69,
Ray Jay Davis, "Weather Modification Law
Developments," Oklahoma Law Review, Vol. 27, pp. 409-439,
Ray Jay Davis, "Legal Uncertainties of Weather
Modification," pp. 32-64, in William A. Thomas, editor, Legal and Scientific
Uncertainties of Weather Modification, Duke University Press, 1977.
Robert D. Elliott, "Experience of the Private Sector," pp. 45-89,
in W.N. Hess, editor, Weather and Climate Modification,
Julie Ferdon, "Federal Weather Modification
Projects: Compensating the Landowner," Arizona Law Review, Vol. 26,
pp. 681-698, Spring 1984.
Allan L. Grauer and Bob Erickson,
Comment: "The Weathermaker and the Law," South Dakota Law Review,
Vol. 1, pp. 105-120, Spring 1956.
Wallace E. Howell,
"Cloud Seeding and the Law in the Blue Ridge Area," Bulletin of the American
Meteorological Society, Vol. 46, pp. 328-332, June 1956.
Ralph W. Johnson, "Legal Implications of Weather Modification," pp.
76-102, in Howard J. Taubenfeld, editor, Weather Modification and The
Law, Oceana Publications, 1968.
Gregory N. Jones, Comment: "Weather
Modification: The Continuing Search for Rights and Liabilities," Brigham
Young Univ. Law Review, Vol. 1991, pp. 1163-1199, 1991.
Jerome W. Kirby, "Judicial Regulation of Weather Modification,"
pp. 55-61, in Ray Jay Davis and Lewis O. Grant, editors, Weather
Modification: Technology and Law, American Association for the Advancement
of Science, Symposium, 124 pp., 1978.
Dean E. Mann, "The Yuba City
Flood: A Case Study of Weather Modification Litigation," Bulletin of the
American Meteorological Society, Vol. 49, pp. 690-714,
Edward A. Morris, "Preparation and Trial of Weather
Modification Litigation," pp. 163-184, in Howard J. Taubenfeld, editor,
Weather Modification and The Law, Oceana Publications, 1968.
C. Oppenheimer, "The Legal Aspects of Weather Modification," The Insurance
Law Journal, Nr. 424, pp. 314-322, May 1958.
B. Standler and Bernard Vonnegut, "Estimated Possible Effects of AgI Cloud
Seeding on Human Health," J. Applied Meteorology, Vol. 11,
pp. 1388-91, December 1972.
Donald D. Stark, "Weather
Modification," California Law Review, Vol. 45, pp. 698-711,
William A. Thomas, "Observations on This Symposium,"
pp. 119-120, in Ray Jay Davis and Lewis O. Grant, editors, Weather
Modification: Technology and Law, American Association for the Advancement
of Science, Symposium, 124 pp., 1978.
About the authorI took several classes in atmospheric
physics during 1971-76, while I was in graduate school, although my emphasis was
in general physics. My first peer-reviewed scientific publication was a paper
that reviewed the published literature on the toxicity of silver iodide used in
cloud seeding. I did scientific research in atmospheric electricity and
lightning during 1971-79 and earned a Ph.D. in physics in 1977. The drastic
decrease in the U.S. Government's financial support for scientific research in
atmospheric electricity caused me to change fields in 1982 from basic scientific
research to practical engineering research on protection of electronic equipment
from transient overvoltages, such as caused by lightning. When financial support
for research in all of my areas of science and engineering was annihilated in
1990, I began to change careers to law. I am currently an attorney in
this document is at http://www.rbs2.com/weather.htm
most recent search for court cases on this topic was on
27 Sep 2002.
My most recent search for state statutes on this topic
was on 20 Oct 2002.
revised 23 Dec 2002
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