I'm sure Dr. Eric Pianka's envisioning (to his class on population dynamics at University of Texas) of an ebola pandemic is only one of many possible tragic human decimation scenarios. While the actual mechanism of civilization's demise is difficult to predict, the probability that it will happen in a dramatic fashion seems rather high, getting higher. Combine all the favorable factors of ever increasing population densities with ever more rickety economic structures and ever more mobile populations and it's like you're preparing Petri dishes for an experiment in human disaster.
Perhaps it's only the months of endless rain in California getting me into a funk, but the prospect of climate change and our utter failure to respond in a meaningful way (whether we can actually do anything to mitigate our contributions is another matter) fills my head with all kinds of ugly disaster scenarios. Climate change could be what sets the stage for a Pianka-style pandemic, or it could go for the glory all by itself. The thing about Global Warming is that while we can observe its onset and some of its corollary effects, we have little knowledge of how it will affect us locally. One thing's for certain: climate change will make agriculture more difficult, which will be tough on many populations around the world, which will make people more vulnerable to agents like ebola or influenza.
So while it's hard to refute Dr. Pianka's vision of pandemic, ebola or otherwise, it is difficult to imagine what has got people in Texas so stirred up that they feel compelled to send death threats and hate mail to college science teachers for suggesting what seems eminently plausible, that civilization is vulnerable. Many of the aggrieved express revulsion at the idea of so much suffering and death.
I wonder if these people have spent any time contemplating the various Armageddon scenarios so popular among their peers in Texas and elsewhere. While it's hard to know whether dying of Ebola in a city littered with other dead and dying would be more unpleasant than the sublime slaughter elucidated in the Christianist "Left Behind" series or in the minds of faithful Armageddonists wherever they may be, there is one thing that separates the science-based vision from the religious one. Scientists are concerned about the fate of all people and are looking for ways to prevent a real-world Armageddon.