Yes, I take those claims with a big dose of salt myself :). First if you are talking about natural events - the thing is - yes humans are under threat of extinction - a few hundred million years from now, probably half a billion years from now. But that is far enough into the future to evolve to humans a second time from the first ever multicellular lifeforms.
When you look at possibilities of extinction in the near future - well the only way it can happen is if we do it to ourselves. And if we do risk making ourselves extinct with technology, as some suggest - one way we could make ourselves extinct is by rushing into space colonization and then starting wars in space or using the powerful technology we develop in that way to harm ourselves. It's not at all clear it makes us safer.
There are near future perils - but nothing that would make us extinct, and they are also extremely low probability.
Chance of an asteroid impact about 0.00001% before 2100. And by 2020 we hope to have mapped 90% of all potential impactors of 140 meters and larger - and civilization threatening asteroids are well over 1 km in diameter.
We could survive even the firestorm / asteroid impact that made the dinosaurs extinct. They didn't have mines, or submarines or any ways of hiding from the danger.
Even without warning some humans would be in subs or underground and would survive, and many more would survive with just a bit of warning, and we'd be likely to have at least many months of warning, long enough to prepare shelters, oxygen supply to last out the firestorm etc.
And with enough warning we could look into ways to deflect it - or if worst comes to worst - evacuate the area of impact - and build shelters and get oxygen supplies for everyone to last out the impact. Some humans would surely survive, maybe a reasonable proportion.
Also - yes we may soon be able to move large masses to Mars, but - it is hardly a desirable place to live.
There is no conceivable disaster that could make Earth anything like as inhospitable as Mars. Even a gamma ray burst - we'd still have an oxygen rich atmosphere and could still breath. Even an all out nuclear war - well - the surface of Mars has no protection from cosmic radiation - easier to live on a radioactive Earth than Mars so long as you have a bit of filtration for the air.
And is hard to beat the convenience of a breathable atmosphere, plants already growing here, animals living here, seas and rivers and oceans, no need to wear spacesuits or construct buildings to hold in atmosphere against a vacuum - or need to make oxygen from ice or sand.
Nobody has suggested any credible disaster that would remove this advantage of Earth over Mars. So if humans were faced with extinction, the place to go to escape from it will always be Earth, not Mars. At least with present day technology and in the next few million years or so.
Still, as you say, this is often presented as the reason to leave Earth and to colonize Mars. But - I think they just haven't thought it through - at any rate not seen any explanation or discussion of it that explains how we could get from where we are now to an Earth that is more inhospitable than Mars.
Also - how could it possibly make sense to start up a civilization on a planet without any significant atmosphere when you already have a planet with an atmosphere?
Imagine if, whenever you need to build a new house, your builders all have to wear spacesuits? And you have to build your house like a tank to hold in the pressure of the atmosphere inside? And you have to make your oxygen from ice or sand to breath? And cover your house with a thick layer of regolith to protect from cosmic radiation?
Surely - even if you are enthusiastic enough to do that yourself, and to pay about 10 or 100 times as much to build your house, or perhaps 1000 times as much or more in the early stages- your children will look at Earth with its breathable atmosphere, rivers, and seas, and want to migrate back there, where everything is so much easier?
Unless we have truly game changing technology like 3D printers and von Neumann machines. That would change everything. But here also on Earth, also for making space colonies, not just on Mars.
We may well build settlements in space - and I think more likely in orbit around Mars than on the surface to preserve science interest of a Mars with native Mars life only (or even no life - that also is of huge interest to science).
Maybe even tens or thousands of people living there - if there is enough interest and motivation for it. If we find new, different forms of life on Mars for instance, might well be motivation even to have thousands of people in orbit around Mars eventually studying it.
However, I can't see us going to Mars to set up viable self sufficient colonies just for their own sake - even if it is possible, what is the point when it is far easier to build a desert colony on Earth, or a sea city or a floating sky city?
And can't see any future in Mars as a place to escape from extinction threats.
This is a personal point of view. The Mars Society is a society of enthusiasts who are sure that we will colonize Mars and are working towards that future in many ways. And Elon Musk of SpaceX and Mars One have this also as their objective.
But - I just can't see the point - as a place to colonize. And many others think the same way. View all this a bit "non plussed". And I am a space enthusiast, extremely keen to find out more about our solar system and watch the results of our space explorations with a great deal of interest.
But this particular colonization initiative - I feel it is a blind alley myself. At this stage anyway, with present and near future technology and based on what we know about Mars at present.
Have written about this in many other answers here. And the news stories are all so much in favour - I see news story after news story about colonizing Mars. I think perhaps because it looks so habitable in the photographs (which are also processed and white balanced to look like an Earth landscape to help the scientists identify rocks, often even with blue skies). Also perhaps partly because of the many science fiction stories about habitable Mars - but our world is not always the same as the science fiction.
We've also had many science fiction stories about Venus jungles. It's so obvious that the surface Venus is not habitable that nobody wants to go there now. But Mars really isn't that habitable either - the old stories of habitable Mars are also far from the truth, as it turned out.
But if you stop and think - it's not nearly as good as it seems in the photos - far closer to the Moon than the Earth for habitability - as a place to colonize.
When you look at possibilities of extinction in the near future - well the only way it can happen is if we do it to ourselves. And if we do risk making ourselves extinct with technology, as some suggest - one way we could make ourselves extinct is by rushing into space colonization and then starting wars in space or using the powerful technology we develop in that way to harm ourselves. It's not at all clear it makes us safer.
There are near future perils - but nothing that would make us extinct, and they are also extremely low probability.
Chance of an asteroid impact about 0.00001% before 2100. And by 2020 we hope to have mapped 90% of all potential impactors of 140 meters and larger - and civilization threatening asteroids are well over 1 km in diameter.
We could survive even the firestorm / asteroid impact that made the dinosaurs extinct. They didn't have mines, or submarines or any ways of hiding from the danger.
Even without warning some humans would be in subs or underground and would survive, and many more would survive with just a bit of warning, and we'd be likely to have at least many months of warning, long enough to prepare shelters, oxygen supply to last out the firestorm etc.
And with enough warning we could look into ways to deflect it - or if worst comes to worst - evacuate the area of impact - and build shelters and get oxygen supplies for everyone to last out the impact. Some humans would surely survive, maybe a reasonable proportion.
Also - yes we may soon be able to move large masses to Mars, but - it is hardly a desirable place to live.
There is no conceivable disaster that could make Earth anything like as inhospitable as Mars. Even a gamma ray burst - we'd still have an oxygen rich atmosphere and could still breath. Even an all out nuclear war - well - the surface of Mars has no protection from cosmic radiation - easier to live on a radioactive Earth than Mars so long as you have a bit of filtration for the air.
And is hard to beat the convenience of a breathable atmosphere, plants already growing here, animals living here, seas and rivers and oceans, no need to wear spacesuits or construct buildings to hold in atmosphere against a vacuum - or need to make oxygen from ice or sand.
Nobody has suggested any credible disaster that would remove this advantage of Earth over Mars. So if humans were faced with extinction, the place to go to escape from it will always be Earth, not Mars. At least with present day technology and in the next few million years or so.
Still, as you say, this is often presented as the reason to leave Earth and to colonize Mars. But - I think they just haven't thought it through - at any rate not seen any explanation or discussion of it that explains how we could get from where we are now to an Earth that is more inhospitable than Mars.
Also - how could it possibly make sense to start up a civilization on a planet without any significant atmosphere when you already have a planet with an atmosphere?
Imagine if, whenever you need to build a new house, your builders all have to wear spacesuits? And you have to build your house like a tank to hold in the pressure of the atmosphere inside? And you have to make your oxygen from ice or sand to breath? And cover your house with a thick layer of regolith to protect from cosmic radiation?
Surely - even if you are enthusiastic enough to do that yourself, and to pay about 10 or 100 times as much to build your house, or perhaps 1000 times as much or more in the early stages- your children will look at Earth with its breathable atmosphere, rivers, and seas, and want to migrate back there, where everything is so much easier?
Unless we have truly game changing technology like 3D printers and von Neumann machines. That would change everything. But here also on Earth, also for making space colonies, not just on Mars.
We may well build settlements in space - and I think more likely in orbit around Mars than on the surface to preserve science interest of a Mars with native Mars life only (or even no life - that also is of huge interest to science).
Maybe even tens or thousands of people living there - if there is enough interest and motivation for it. If we find new, different forms of life on Mars for instance, might well be motivation even to have thousands of people in orbit around Mars eventually studying it.
However, I can't see us going to Mars to set up viable self sufficient colonies just for their own sake - even if it is possible, what is the point when it is far easier to build a desert colony on Earth, or a sea city or a floating sky city?
And can't see any future in Mars as a place to escape from extinction threats.
This is a personal point of view. The Mars Society is a society of enthusiasts who are sure that we will colonize Mars and are working towards that future in many ways. And Elon Musk of SpaceX and Mars One have this also as their objective.
But - I just can't see the point - as a place to colonize. And many others think the same way. View all this a bit "non plussed". And I am a space enthusiast, extremely keen to find out more about our solar system and watch the results of our space explorations with a great deal of interest.
But this particular colonization initiative - I feel it is a blind alley myself. At this stage anyway, with present and near future technology and based on what we know about Mars at present.
Have written about this in many other answers here. And the news stories are all so much in favour - I see news story after news story about colonizing Mars. I think perhaps because it looks so habitable in the photographs (which are also processed and white balanced to look like an Earth landscape to help the scientists identify rocks, often even with blue skies). Also perhaps partly because of the many science fiction stories about habitable Mars - but our world is not always the same as the science fiction.
We've also had many science fiction stories about Venus jungles. It's so obvious that the surface Venus is not habitable that nobody wants to go there now. But Mars really isn't that habitable either - the old stories of habitable Mars are also far from the truth, as it turned out.
But if you stop and think - it's not nearly as good as it seems in the photos - far closer to the Moon than the Earth for habitability - as a place to colonize.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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