Serious question: will Earth after a super volcano be less habitable than Mars?
I'm no expert but my instinct is a strong no. Earth will still be more habitable than Mars even if 95% of species die off, the planet cools 20 degrees, and the air turns half-toxic.
To me, if you are really concerned about human extinction, bunker tech seems like a better investment than space tech. This may not always be true - but at today's level of technology it seems true to me.
Long answer: The effect of volcanic eruptions on climate is somewhat overblown in popular culture. In recorded history, we only have a handful of VEI7 eruptions, and only one within the range of well-recorded history (that one being Tambora). Tambora is known to have been followed by a particularly severe summer, but it was also concurrent with climatic minimums due to the "Little Ice Age" and the solar cycle. Some other VEI7 eruptions are known, but it's highly speculative how severe any sort of climatic was response, both locally and globally.
A supervolcano would be a VEI8 eruption. There are two known VEI8 eruptions in the history of humanity, both well before recorded history. People have claimed that one of these, the Lake Toba eruption, is responsible for a severe bottleneck in human population, but work has shown that a) global ash distribution is identifiable, b) wildlife populations don't seem to have been too affected, and c) even relatively close populations don't seem to have collapsed.
In other words, the largest eruption in the climatic record was incapable of producing an extinction-level event. A Yellowstone caldera eruption wouldn't be all that much larger. For anyone in the ash cloud, it would be problematic for the short term, but that's a relatively short term issue (1-2 years). More serious would be the loss of productive farmland in the US for perhaps a decade or so, but that wouldn't be anywhere near extinction-level for humanity.
> More serious would be the loss of productive farmland in the US for perhaps a decade or so, but that wouldn't be anywhere near extinction-level for humanity.
I'm not sure about that. Maybe not on the surface, but I could easily see a 40% drop in U.S. agricultural output (number made up) causing massive global turmoil, even potentially leading up to a world war.
Our world is so interconnected that a strong enough shock in one area can arguably start a runaway positive-feedback loop of destruction.
If you were to say that Yellowstone erupting leads to World War III, well, I wouldn't argue that it's implausible. But, similarly, world wars are not extinction-level events. Nuclear weapons can't cause extinction: nuclear winter is basically volcanic winter with a much less effective stratospheric pump (a VEI6 eruption, such as Krakatoa, pushes at least 1km³ of rock into the air; a VEI8 eruption, like Yellowstone, is 100× that). There's a hard cap on the proportion of your population you can mobilize to front-line troops, and while it is possible for one side's losses to exceed this fraction, on a global scale, only 60% or so of the population can be killed in a war, a far cry from the 99.9999% you'd need to kill to effect extinction.
It's certainly possible for an astonishingly large proportion of the population to perish, but extinction requires extermination to be nearly complete.
I think your expectations are overly optimistic. Perhaps it wouldn't be 99.9999%, but in the event of global nuclear war, supply chains for virtually everything (including food) will come to a complete halt. People in cities will be utterly screwed when fuel and food run out.
People in farmland might not be that much better off. Masses of starving, potentially-armed people searching for food will not necessarily be the most respectful of people's property rights. We can expect animal wildlife populations to plummet as they're killed for food, and agricultural output to drop precipitously as supply chains for fuel, fertilizer, and non-terminator-gene seeds go to zero, not to mention as it becomes exceedingly difficult to protect large patches of farmland from raids.
We have exhausted enough of the easily-accessible resources close to the Earth's surface that all it takes is a sufficient dip in technology, and we enter a rut which we can never get back out of.
That's reasonable but even in a world war, you need only put people on nuclear submarines to protect humanity from extinction. Martian colonies are not necessary.
I think at the point where you're talking about saving fewer than hundreds of thousands of people out of billions (<= 0.01%), it's functionally an extinction-level event for humanity.
Only in the most pointlessly absolute of interpretations.
Ten might as well be zero. 50 people (25 pairs) is necessary with complete control of breeding in order to have sustainable genetic diversity. Without complete control, hundreds are necessary in any given pocket of civilization.
Even if there were tens of millions of humans remaining, there is virtually zero chance of meaningful recovery since all of the low-hanging fruit of industrial-age energy resources have been mined.
Depends on your horizon, but if you look at how fast humanity progressed in 2,000 or even 500 years, I think a recovery from a million+ people in a few thousand years is very realistic, especially if knowledge is adequately recovered through books.
Only up until the technical level of the industrial revolution. Getting past that would require easy access to an easy to use energy source, i.e. fossil fuels. None of which are left. Today we dig kilometers under the seabed to access energy. A society just entering the industrial revolution will have not the knowledge, tools, or materials to do that.
The Bible makes no mention of humans living on other planets. Mars is also named after a Greek god. It would be a good bet you'd be out of His jurisdiction.
>Serious question: will Earth after a super volcano be less habitable than Mars?
Depending on how far you were from the eruption you could die the first hour within several hundred miles. Outside of that radius you're going to be exposed to the ash/particulate which you DO NOT WANT TO BREATHE as it gets in your lungs and basically becomes a concrete-like sludge that will suffocate/drowned you from hours to days after you inhale enough and some of it will be so fine that even holding a wet towel to your face or using a common commercial respirator won't do a damn thing.
Within a month or two most plant life and animal life would be dead and markedly less sunlight would be reaching the surface of the Earth, the surface temperatures would quickly get below freezing as well.
At this point, while the pressure on the surface is survivable, it would be effectively as deadly as Mars. Some humans might survive on the surface of Earth the first year but conditions would be hellish and miserable, any chance of real survival would be individuals living in government bunkers around the world that have access to fresh water and food storage. If weather co-operated some of these people would survive until the ash had settled out of the atmosphere enough to allow plant life to begin to grow again and once it could it should start spreading relatively quickly as andisols are some of the most fertile soil on earth (andisols are formed from volcanic ash as it breaks down).
hours to days after you inhale enough on Earth vs. unconscious in seconds and dead in minutes on Mars. (Earth Wins!)
markedly less sunlight on Earth vs even less on Mars. (Earth Wins!)
most plant life and animal life would be dead on Earth vs. zero plant or animal life on Mars. (Earth Wins!)
In some areas surface temperatures would quickly get below freezing due to an average 3c drop vs. Much of mars could be warmed by 100c and still be below freezing. (Earth Wins!)
So really, even then the Earth with still be a paradise compared to Mars.
What supervolcano are you predicting? The last Yellowstone caldera distributed its tephra only within the range roughly of the Great Plains--people in Chicago wouldn't see ashfall. Sure, airline travel would be screwed.
The rest of your comment is... I mean, to seriously believe that, you'd have to believe that there's severe extinction level events every million years or so, and the frequency of those kinds of extinction-level events is closer to every 50 million years.
>What supervolcano are you predicting? The last Yellowstone caldera distributed its tephra only within the range roughly of the Great Plains--people in Chicago wouldn't see ashfall.
Mt St Helens dropped from trace amounts to 1/2 inch of ash as far south as most of Colorado and as far east as western Minnesota. Ritzville, more than 250 miles away, had 2-5 inches of ashfall. Mt St Helens was comparable in volume to Vesuvius and was less than 1 cubic kilometer of volume, Oruanui eruption which was a relatively small super volcano eruption was estimated around 1170 cubic kilometers and dumped 7 inches of ash 620 miles away on the Chatham Islands.
Toba released between 2000 and 3000 cubic kilometers of ejecta (800 cubic kilometers being ashfall), killed a significant portion of humans alive at the time, created a genetic bottleneck responsible for the current genetic makeup of billions of people, lowered the temperature as much as 27F in places (5.4-9F globally). They found ash deposit from it in the South China Sea 600-800 miles away. If that happened in the middle of America, keep in mind the U.S. exports an absurd amount of its crops, you're talking bye bye population in North America, considerable cooling for Europe which would likely mean no crops in northern Europe. Then you lose the oil, natural gas and coal exports from North America. Air travel would likely be grounded for months the world around, if we keep assuming it's yellowstone in this scenario then if it happens in the winter here southern hemisphere crops would likely have poor yields depending what part of summer it is, if it happened in the summer here then European and Asian crops would suffer. Massive food shortages, fuel shortages, abnormally cool weather which could further effect crop growth and could get some areas into freezing temperatures during winter consistently instead of extremely rarely. Mt St Helens triggered air quality detectors in the northeastern United States so you'd likely have a deterioration in air quality the world around as well. Of course as most of the population of North America is dying from the ash fall starting in as little as a day or two you now have fewer and fewer people to fight fires when they break out, at some point you likely have massive fires burning through entire cities adding more smoke and ash to the atmosphere, some of these will move into forests unchecked, ash will have toppled some to many trees allowing fires to spread easier in forests, even if someone was here to launch planes to try and extinguish the planes the ash won't have cleared enough from the air to allow flight. Etc etc, so on and so forth. What the other guy in this thread, and the people downvoting me forget, is that the last time one of these happened... we were living in very very primitive structures and our population was likely under 1 million (at 10,000 BC population estimates are between 1 and 15 million, the last supervolcano eruption happened around 24,000 BC, lake Toba around 74,000 BC).
Toba was 100x more powerful than Tambora that I think I saw mentioned elsewhere in this comment chain. tambora happened in 1815 and cooled global temperatures by 0.95F / 0.53C, per wiki
>The second-coldest year in the Northern Hemisphere since around 1400 was 1816, and the 1810s are the coldest decade on record. That was the consequence of Tambora's 1815 eruption and possibly another VEI-7 eruption in late 1808. The surface temperature anomalies during the summer of 1816, 1817, and 1818 were −0.51 °C (−0.92 °F), −0.44 °C (−0.79 °F), and −0.29 °C (−0.52 °F), respectively.[8] Parts of Europe also experienced a stormier winter.
> Toba released between 2000 and 3000 cubic kilometers of ejecta (800 cubic kilometers being ashfall), killed a significant portion of humans alive at the time, created a genetic bottleneck responsible for the current genetic makeup of billions of people, lowered the temperature as much as 27F in places (5.4-9F globally).
The Toba genetic bottleneck theory is generally considered discredited in modern scientific circles. There is evidence of an ash layer as far as Lake Malawi, but there is no evidence of any significant disruption to flora and fauna. It failed to even show a major cooling event in that region.
> at some point you likely have massive fires burning through entire cities adding more smoke and ash to the atmosphere, some of these will move into forests unchecked
At this point in your little rant, I broke down laughing. You're clearly someone who has bought into the nuclear winter theories, and the most outlandishly over-the-top ones at that. We've been able to observe out-of-control boreal forest fires in recent decades (such as the McMurray fire not two years ago), and the effects of such fires are extremely short-lived. Even setting an entire country's oil fields on fire failed to produce any significant regional effect, much to the chagrin of the nuclear winter fear-mongers.
> Toba was 100x more powerful than Tambora that I think I saw mentioned elsewhere in this comment chain. tambora happened in 1815 and cooled global temperatures by 0.95F / 0.53C, per wiki
Tambora is the strongest eruption in recorded history. It is also the strongest link we have to a volcanic winter, the effects of which were so devastating that you have to go read books on Tambora to discover that it happened. The only other eruption posited to have had enough of an impact to cause political repercussions is Huaynaputina in 1600, which may have caused the Russian famine during the Time of Troubles.
There is a significant gap between "measurable drop in global temperature" (which is well-attested) and "significant population drop due to crop failures" (which is not), and an even more significant gap to "extinction of several species as a result of major climactic changes."
To believe that a supervolcano is capable of making the human race extinct, you'd have to believe either that >99% of species are less susceptible to extinction than humans, or that extinction-level events happen every few million years, the latter of which is contradicted by fossil evidence.
I'm no expert but my instinct is a strong no. Earth will still be more habitable than Mars even if 95% of species die off, the planet cools 20 degrees, and the air turns half-toxic.
To me, if you are really concerned about human extinction, bunker tech seems like a better investment than space tech. This may not always be true - but at today's level of technology it seems true to me.