“Their true numbers, Nevins concluded, are "considerably higher than the UN agency estimates." Gerardo seemed to fit this category.

Another potential "black swan," to use the U.S. Department of Homeland Security's own term, is the impact of environmen tal breakdown in the world. The numbers put out by agencies and organizations regarding the future displacement of people caused by climate change are in live debate and range between 150 million and 1 billion by 2050. According to one report, these displacements will be "staggering," without an antecedent in human history. Already disasters are displacing "three to ten times more people than conflict and war worldwide, according to the Norwegian Refugee Council.”