Global climate change, deforestation, heavily industrialized agriculture, and wildlife decimation have contributed to the emergence and spread of modern plagues, argued Mark Jerome Walters in a October 17th Wilson Center meeting. His comments expanded on his recently released book Six Modern Plagues, which explicitly connects six epidemics – West Nile Virus, mad cow disease, HIV/AIDS, hantavirus, Lyme disease, and a new strain of salmonella – to human-induced environmental change. In fact, Walters believes that humans "are bringing these epidemics on ourselves through radical changes in the environment."

Walters communicated this message through the use of stories about two Americans, whose experiences with epidemics "teach us that our health and well-being are dependent on and interconnected with fellow humans, natural systems, and other species." He told the story of Enrico Gabrielli, who contracted West Nile Virus in New York City in the summer of 1999. According to the National Climatic Data Center, New York City was experiencing the hottest July ever recorded in the city due to global warming. Enrico's home lacked air-conditioning, persuading him to spend his nights outside where he was bitten by the disease-carrying mosquito. Walters explained that the path taken by this mosquito was long and complex. West Nile Virus's journey to the U.S. began when migrating storks were forced to land in Israel to rest because of abnormally hot weather and high winds. Testing done by the Israeli government concluded that these birds were carrying West Nile Virus and passed it to other birds and mosquitoes in the area. Soon thereafter, humans in the region began dying. It is not clear how the virus got from the Middle East to New York City. What is clear is that the migration pattern of birds and climate change interacted and led to Enrico's illness.

Similarly, Walters told the story of Jeff Dunbar, who fell ill with Lyme disease due to radical ecological change in Michigan. Based on his conversation with a Rutgers ecology professor, Walters found that deforestation often leads to the decimation of animals, often predators that cannot quickly adapt to new habitats or sources of food. As these species leave the forest, resourceful animals such as deer and mice proliferate. This is precisely what happened in the woods near Jeff's campus. Rapid deforestation in the area led to an abundance of deer and mice that ventured out of the woods onto Jeff's campus in search of food. Ticks left on campus by the deer thrived on the increased population of mice, from which they contracted Lyme disease. Walters stated that if there had been more predators in the forest, there would have been a greater variety of animals from which ticks could have chosen, making it less likely that ticks would have chosen mice and contracted the disease. Thus, human destruction of the forest ultimately increased Jeff's chances of getting Lyme disease.

Both of these examples point to the fundamental role humans play in spawning these epidemics. Walters remarked that this is good news since humans are part of the problem, they can be part of the solution. He said that with this heightened sense of humans' place in the world we understand "we are not so much victims of nature but of our actions, and we have the power to change them." Audience discussion centered on how to get the media involved in an education campaign that would connect Americans' health concerns with environmental activism.