While humankind is obsessed with economic growth, terrorism, and unverified rumors of weapons of mass destruction, a much greater threat to both individual and societal security is developing with frightening rapidity the increasingly probable failure of the biospheric life support system to continue maintaining conditions that have been favorable to humans for 160,000 years.Worst yet, humankind s unsustainable practices are the primary cause of this threat. An uncharitable person might conclude that humankind is suicidal. After all, why cause global warming, acidification of the planet s oceans, and drive many of the life forms _sharing the planet into extinction if humankind does not have a death wish? However, reasons to hope exist. Major changes in human behavior could result in a shift from unsustainable to sustainable practices. To be effective, this shift must be based on an objective analysis of the risks to humankind s security based on information generated by the experimental sciences. This analysis would be a major, new undertaking for the experimental sciences, but it is necessary to a sustainable future for humankind.