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Workshop on "Global Scale Diasters" Explores Human Consequences of Asteroid and Comet Threat

Press Release From: University of California-Davis
Posted: Thursday, May 16, 2002

Social scientists convened in Irvine California on Friday, April 11, 2002 to discuss human reaction to the possibility that a large asteroid or comet will collide with Earth, perhaps causing global devastation. The purpose of this workshop was to consider managing disasters that are far beyond the scope of local, regional, and national authorities. Although the papers focused explicitly on the threats to Earth posed by asteroids and comets, much of the material was applicable to other low-probability high-consequence events. The session was a sequel to a technically oriented workshop sponsored by the American Institute of Aeronautics and Astronautics and held in Spain in 2001. This earlier conference focused on finding and intercepting dangerous near earth objects. Participants there realized that purely technical solutions were not enough, and urged a follow-up workshop to explore the socio-cultural and psychological aspects of the threat.

Although we can see the record of impacts on the surface of the Moon the threat to Earth was not widely appreciated until the latter part of the 20th century when scientists discovered that asteroid impacts were the most likely cause of past massive extinctions on Earth including the extinction of dinosaurs 65 million years ago. We know that objects hit Earth's atmosphere all the time; most burn up, but some make it through to the Earth's surface. Small objects are common but do little damage (one literally smashed the trunk of a car). Large objects are rare, but can do immense damage and very large objects have the potential of destroying all human life. We can expect a major local disaster about once every thousand years, a global disaster about once every million years, and an extinction-level event about once every hundred million years.

Astronomers have made tremendous progress finding and tracking potential interlopers in our solar system, and it may be possible to predict an impact decades or even centuries in advance. We can develop the technology to destroy or deflect some approaching objects, but not all threatening objects have been found and there is a 40 percent chance that a major comet or asteroid would arrive with very little advance warning. It could be a matter of days before we realize with any degree of certainty when and where an object will hit Earth.

Issuing a warning can itself have a profound effect, even if the prediction turns out not to be true. Who issues the alert, and at what level of probability that the object will hit Earth? At present, no governing or advisory body is in a position to oversee alerts.

Advance warning would allow time for planners to generate alternatives, consult, carefully weigh and evaluate new information, reach decisions, build consensus, and make careful plans for implementation. On the other hand, substantial warning may place the event beyond the institution's planning horizon, and discourage people from attending to the threat. Ample warning increases the opportunity for special interest groups to form, generate dissent, and initiate political action. Advance warning is likely to incur certain costs such as an economic slowdown, and a lowered quality of life. Warnings could be counterproductive if they routinely prove to be false alarms, or if the public does not believe that there are ways to mitigate the threat. Governments may consider it to their benefit to create a "spin" that decreases warning costs. Little or no warning raises prospects of horrendous casualties and the catastrophic failure of rescue and recovery operations.

Authorities at many different levels including top policy makers, enforcement agencies such as the military and police, disaster and relief workers, and residents of affected or at-risk areas will make decisions with life-death outcomes. Such decision-making could be viewed as an interactive process that empowers people to take self-protective steps. Offering the public objective information is only one small step. Widespread understanding is unlikely if the information is not geared to people with a sixth grade education. Cultural and psychological factors will influence how the public processes the warning and whether or not they then take sensible action. People understand that there are "official" and "unofficial" parts of a government announcement, and they will not always listen to scientists. People who call astronomers for reassurance do not always accept that reassurance at face value. Furthermore, many people adhere to religions that predict that the end of the world will come about as the result of an asteroid strike.

It will be difficult to avoid falling prey to wishful thinking (including denial, rationalization, and buck-passing) and to panicky, ineffective decision-making brought about by extreme stress. Other threats to planning and survival include the "giggle factor" (that is, ridicule on the part of people who lack foresight and are so absorbed by the immediate here and now that they are completely insensitive to unlikely events); sensationalized and rapidly abandoned dire predictions; supernatural interpretations that direct attention away from rational searches for survival strategies; disaster myths; a widespread and growing lack of trust in the US government; and the misinterpretation of an asteroid impact as an act of war. Because we have little or no experiential base for planning for very rare occurrences, planning efforts may lead to "fantasy documents" that bear little or no correspondence to the actual unfolding of events.

Casualties will result from the primary effects of the impact and from "secondary effects" associated with the breakdown of the infrastructure including transportation and communication systems, the loss of water and food supplies, and the loss of home and livelihood. Disasters have ripple effects, spreading out from the epicenter and affecting ever-larger numbers of people. In essence there are "circles of victims" beginning with the dead and injured and expanding to include the bereaved, the disaster workers, and (through the media) society at large. People who are physically unscathed may bear profound psychological scars, including post-traumatic stress disorders. Psychological problems may appear long after the fact. Overall, minimizing and managing casualties could be an overwhelming task. Our society may not be able to maintain the luxury of poring through the rubble, looking for survivors when there is only the slimmest chance that anyone could remain alive, and we may have to come up with tough new standards for managing triage.

Extinction is generally a two-step process, beginning with a calamitous event that kills the preponderance of members of a species followed by a series of "local disasters" that "mop up" the survivors. One way for Homo sapiens to minimize the risk of extinction is to become a two-planet species. Another possibility is to create "survival communities" in the form of stout underground shelters that are able to withstand a large impact and the functional equivalent of a nuclear winter. Risk is reduced if survival communities are widely dispersed (so that people who survive the initial impact will not all succumb to the same localized secondary catastrophe) and if each community is relatively large (over 500 people each). Establishing underground or orbiting shelters for some but not all people raises issues of authority, selection criteria, enforcement procedures, and public acceptance and buy-in.

To some extent plans for establishing permanent communities on the moon or on Mars can inform our plans for re-establishing ourselves on Earth following a near extinction-level event. Post-impact recovery will depend on such factors as population size and growth, rate of depletion of stored supplies, and the restoration of means of production. Psychological problems and social conflicts that are kept under control during the period of "button up" may break loose during the re-emergence stage. Since they will function in isolation from one another during the period of isolation and confinement, there may be some tendency for different communities to become separatist by the time that they emerge from their shelters. To reduce the risk of hostility, aggression, and destructive competition among surviving groups, we might try to imbue a strong overall culture and make sure that these separated communities remained in constant communication during the "button up" period.

The workshop concluded with an appeal for additional research. It is not entirely clear how to plan for unprecedented events. How can we encourage study and preparation without raising fear? To what extent can we draw on past experience as we think about the unthinkable? Are atomic blasts, volcano eruptions, major earthquakes and tsunami useful analogues? How can we develop warning systems that do more good than harm? Certainly we cannot devote a substantial portion of the GNP to protecting ourselves from remote events, so how can we ensure that the relevant scientific, industrial, medical and humanitarian organizations can grow quickly at the "moment of truth?"

An Australian astronomer, Ray Norris, notes that a supernova would be likely to depopulate all planets within 50 light years. A Gamma Ray Burster is even more formidable, releasing energy on the order of five magnitudes the order of energy released by a supernova. It can exterminate life over many thousands of light years. Norris calculates that supernovas and GRBs should activate Earth's "reset" button every 200 million years but as far as Norris can tell this has not happened for about twenty times that period. Perhaps our luck will continue to hold, perhaps not.

Harvey Wichman, Director of the Aerospace Psychology Laboratory at Claremont-McKenna College, and Ivan Bekey, an engineer with the International Academy of Astronautics and organizer of the technical workshop held in Spain organized the Irvine Conference. The Conference was sponsored by the Kravis Leadership Institute, Ron Reggio Director, and had strong support from the Western Psychological Association. Speakers included Clark Chapman, Office of Space Studies, the Southwest Research Institute; Benny Peiser, Department of Social Anthropology, Liverpool John Moores University UK; Albert A. Harrison, Department of Psychology, University of California, Davis; Geoffrey Sommer, Policy studies, RAND Corporation; Lee Clarke, Department of Sociology, Rutgers University; Douglas Vakoch, Psychologist, The SETI Institute and Tammy Calvano, now of New Mexico State.

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