MEGA-SCALE EVENTS: NATURAL DISASTERS AND HUMAN BEHAVIOR

A record of mega-scale geological events is preserved on the rocky planets and satellites. In the past, “catastrophic” events on Earth have caused only local collapses of social structure or civilizations. For example, compelling evidence indicates that earthquake storms caused the demise of the Bronze Age in the Aegean and eastern Mediterranean ~1225-1175 B.C. The manipulation of the Nile River by humans for ~7000 years has affected increasing areas of the Nile, and now, the Mediterranean Sea. In ~900 A.D., a shallow earthquake on the Seattle fault sent a tsunami throughout the sound, burying Native American fire pits beneath sand swept ashore by the wave. Now, human population has increased so much, and our civilization has become so globally connected, that relatively "small" mega-scale events can have much more severe geologic, ecologic, and social consequences than even a few hundred years ago. Today, over 3,000,000 people live and work in the Seattle area, and the same tsunami event could have a much larger effect locally, with economic repercussions from the devastation of this high-tech area spreading around the globe. We cannot tell which of, or when, the many possible geologic mega-scale events will occur, but we can easily diagnose that one mega-event is here: humans affecting the physical and biological state of planet on a massive, and dramatically rapid, scale. The global fragility of our species is dramatically illustrated by the potential of the SARS epidemic of 2003. Without rapid detection, acknowledgment of the problem, aggressive monitoring, and treatment by organizations like the Centers for Disease Control (CDC), a catastrophic SARS pandemic might have occurred (and still may?). By analogy, we have already detected and defined many aspects of human behavior that are jeopardizing the planet. Unfortunately, we are reluctant to acknowledge our abuse of our water and soils, the consequences of our unfettered energy and mineral consumption, and our contempt for the rest of the ecosystem. If the earth-science community could build a “CDC-for-planet Earth” to institute aggressive monitoring, identify and understand trends, predict their consequences, and suggest and evaluate alternative actions, we might yet be able to set the path to rescue ourselves and our ecosystem from that mega-scale terminal event called “extinction”.