Professor of Anthropology, Brian Fagan, the author of such books as The Long Summer, discussed El Nino's and other factors involved in climate change. El Nino's, which are created when atmospheric pressure in the Pacific Ocean causes warm water to surge, are the "most powerful factor in climate after the seasons," he noted, adding that it has only been since modern instrumentation came into use that it was realized that they have a global effect.

He characterized the unpredictable El Nino cycles as having a rippling kind of effect that could cause either droughts or torrential rains depending on the location. Fagan said such El Nino-associated droughts may likely have been a contributing factor to the demise of the Mayan culture.

"We're very vulnerable to extreme climate events," he commented, citing the deaths of 20-30 million people who died as the result of famine that was related to El Nino's and monsoons that occurred in the 19th century. "And the potential for disaster is much higher now," because of increased populations and people living in coastal regions, Fagan stated. Even more devastating than El Nino's are category 5 hurricanes which can quickly wipe out entire areas, he pointed out.