Thursday, August 12, 2010

The Worst Weather in History

We hear the reports every season. The worst flooding that has ever occurred in Iowa. The most intense heat wave ever to envelop Russia. The most long-lasting drought in the history of Texas. Of course, all of these statements reflect data from human records which, at most, document weather conditions over the past few hundred years, a mere instant in the course of Earth's natural history.

Throughout the evolution of our planet, spanning 4.6 billion years, its surface has been constantly changing, molded by the forces of continental drift, rising and falling sea levels, uplift, rifting and the erosive power of water, wind and ice. Many land areas have, during various periods, been covered by swamps, glaciers, deserts, shallow seas, plains and mountain ranges. Massive flooding, prolonged drought, glaciation, changing ocean currents, hurricanes, volcanic eruptions, earthquakes and asteroid impacts have all played a role, sculpting the land, altering the climate and directly impacting the evolution of life.

Unfortunately, we humans tend to rely on recorded history when we build our towns and cities in deserts, along rivers, on volcanic slopes, atop faults or on barrier islands. We rely on levees, canals, modern engineering, good luck and divine intervention to protect us from nature's fury. Alas, we learn that our records are incomplete, our technology is inadequate, our luck is fickle, our gods are impotent and our planet is still evolving.