alt Hacker NewsLife on Earth is going to be temporary - the Sun itself already guarantees that on a long timeframe. But on far more immediate time frames there have been countless mass extinction events and countless more will happen - in fact we're well over due for one. One could very well happen tomorrow - there won't necessarily be any warning.
For instance one hypothesis for one of the most devastating mass extinction events was mass volcanic eruptions. The volcanos don't kill you, usually, but they blot out the sky which not only sends temperatures plummeting but kills all plantlife, which then rapidly kills anything that depended on those plants and on up the food chain. Another hypothesis for another mass extinction event was an unfortunately directed gamma ray burst. It would end up killing life off through a similar ends, even if the means to get there is quite different.
It's likely that the only means to 'beat' these events in the longrun is technology and expanding into the cosmos - becoming a multi planetary species first and eventually a multi star system species. That we (and many other species species for that matter) seem to have this instinct to expand as far as we can is probably just one of the most primal survival instincts. Concentrated over-adaption to a localized region and circumstance is how you get the Dodo.
The effects of the largest volcanic events can be even more dire than that.
The Permian-Triassic boundary extinction, the "Great Dying", is though to be related to the massive Siberian Traps large igneous province. This eruption had the unfortunate luck to be through one of the largest and oldest sedimentary basins on the planet. So, magma was introduced into this massive basin, cooking sedimentary docks including coal, organic-rich shales, and evaporites (salts).
The result was truly massive gas emission, producing over time hundreds of pipes up to ~1 km in diameter that ejected a nasty mix of gases, mostly steam and CO2 (lots of CO2), but including chlorinated organic compounds from the high temperature reaction of the salts and fossil carbon. The halocarbons would have been enough to collapse the ozone layer.
Afterwards, CO2 levels and temperatures stayed elevated for five million years (equatorial ocean temperature may have been too high for vertebrate life to survive there). The ordinary process by which CO2 is drawn back down (by absorption into the oceans and deposition of carbonates via Ca/Mg eroded off continents) was interrupted for some reason, perhaps because silica-utilizing ocean microorganisms had been killed off, causing those cations to instead form clays in a process called "reverse weathering".