Themken: There are several bad things that has a likelihood of over 1% to happen within the next five years. A lot of them I cannot mention due to the forum rules but here is one allowed:
A big fat sun flare is overdue to come toast our electronics.
Even worse... I read a month ago or so in the news (Helsingin Sanomat) that the magnetic field of Earth has weakened by about 10% during the last two centuries or so. Maybe it is due to the magnetic poles preparing to change their places or something, but damn that does sound alarming by itself.
Why? Because the magnetic field is what is protecting our atmosphere from sun's radiation ripping it all away.
Look what happened to Mars. By all accounts, it used to have water/ice on the surface and some kind of atmosphere, but at some point it lost its protective magnetic field (due to Mars' core stopping the movements that produced the magnetic field), and over the time the sun ripped its atmosphere away, leaking it to the space. Apparently Mars still has a weak atmosphere, but it still keeps "leaking" to the space due to no protective magnetic field.
So who knows, maybe our atmosphere, seas etc. are slowly but surely already leaking to the space as well, we just don't notice it as it is happening relatively slowly (but increasingly so, unless the 10% decrease in the magnetic field strength is merely temporary). Maybe we could prolong that leaking process by burning more CO2 to the atmosphere, making it stronger.
So yeah, we can certainly come up with all kinds of threats that could cause all life going extinct on planet Earth. In a way it is kind of a miracle we are all still alive. Maybe we shouldn't be?