I'm not sure if this is the first science fiction story to tell of a lone biologist creating a plague, but Frank Herbert's "The White Plague"[1] was written in 1982 and presages a time (in 1996 no less) that a single actor, motivated by personal tragedy, could create and release such a thing.
In a sense though, this notion that technology can give individuals unimaginable power has also been a theme with Robert Heinlein (I think), where he wrote about an easy-to-manufacture superweapon which basically gave anyone the ability to destroy the world. It was also a theme in Kurt Vonnegut's "Cat Cradle" although that's a little bit more of a stretch.
It's true that our destructive capability scales with the amount of energy that we can harness. And it's also true that biological threats are under-perceived. But it seems to be that biology is inherently messy to avoid being too susceptible to annhiliation. That is, yes, it may be possible to create a plague that wipes out 50% of humans - but in the scheme of things, that's not the end of the world. Certainly not the end of humans (not even close!). And it seems that the likelihood of creating such a pathogen is exceedingly small. Indeed, I'd estimate that you couldn't kill more than 10% of people with a single plague.
But since we're talking about catastrophe, it's interesting to wonder about whether a single human could end the world, and if so how. The most likely way (and rather dramatic way) would be to maneuver a large asteroid to impact the Earth. Energetically, it's entirely possible to do. As for nuclear war, I'm not entirely convinced that would really be the end for humans - although it's certainly possible. Another way to end the world might be to release mega-tons of CFCs into the upper atmosphere, intentionally destroying the ozone layer. I can't think of any other scenarios!
In a sense though, this notion that technology can give individuals unimaginable power has also been a theme with Robert Heinlein (I think), where he wrote about an easy-to-manufacture superweapon which basically gave anyone the ability to destroy the world. It was also a theme in Kurt Vonnegut's "Cat Cradle" although that's a little bit more of a stretch.
It's true that our destructive capability scales with the amount of energy that we can harness. And it's also true that biological threats are under-perceived. But it seems to be that biology is inherently messy to avoid being too susceptible to annhiliation. That is, yes, it may be possible to create a plague that wipes out 50% of humans - but in the scheme of things, that's not the end of the world. Certainly not the end of humans (not even close!). And it seems that the likelihood of creating such a pathogen is exceedingly small. Indeed, I'd estimate that you couldn't kill more than 10% of people with a single plague.
But since we're talking about catastrophe, it's interesting to wonder about whether a single human could end the world, and if so how. The most likely way (and rather dramatic way) would be to maneuver a large asteroid to impact the Earth. Energetically, it's entirely possible to do. As for nuclear war, I'm not entirely convinced that would really be the end for humans - although it's certainly possible. Another way to end the world might be to release mega-tons of CFCs into the upper atmosphere, intentionally destroying the ozone layer. I can't think of any other scenarios!
[1] https://en.wikipedia.org/wiki/The_White_Plague