msjh, I did a triple masters in public health, epidemiology and biostatistics. I have no illusion that a global pandemic is in our future, of a SARs (SARS-CoV), H5N1, Zika, Influenza, Ebola or similar form. The millions of years of development on the planet for organisms never provided the vectors that we have today, and the lack of concern on the issue itself, outside of CDC, ECDC and other institutions that are charged with responding to outbreaks. The history of our misuse of antibiotics is depressing; we have ensured that the exiting tools on hand to manage infections has been compromised, (but we got happier chickens to turn into nuggets), and established the next series of superbugs, with the latest revelation of a new MRSA yesterday.
Overcrowding, poor water supply, and lousy public hygiene guarantees that there is a bad day out there on the horizon. Pray that the geeks that took up science instead of twitter can act fast enough to isolate, identify, and develop attenuated samples to provide antibiotics and antivirals in a time that is meaningful to the outcome. We have been very lucky to date; the most serious diseases are to some extent constrained by their own lethality. It is a matter of statistical certainty that at some time, an aerosolised, lethal, slow onset vector will emerge, and at that time it will be a challenge to the capability of the planet to respond. History has shown that the delay in acknowledgement by the political masters alone will make it difficult to put the genie back in the bottle.
If you are wondering about the next apocalyptic event, historically, we get hit by asteroids of consequence rarely, and those that are extinction level in epochal timeframes, yet catastrophic disease outbreak that can take out a large percentage of the global population occurs quite frequently, every couple of hundred years, we get whacked hard, and sometimes, much more frequently, as in recent times, but we have successfully intervened in the major events in the last 40 years. That is by good management, and a huge dose of luck. Luck is not a plan.
The massive population explosion of the planet places us at risk from all stressors of the ecosystem we are a part of, going from 1B around 1800 to 7.6B today. It is quite conceivable to have an event in the next few decades that takes out 30% of the population, it has happened before, we are currently losing the race against the bugs.