A) Overpopulation
B) Nuclear holocaust
C) Fatal pandemics
D) Destruction of ecosystem
E) Global warming
F) Collision with asteroid / comet
G) Solar / stellar cataclysm
H) The Technological Singularity
I) Other

Other responses:

- Something we'll never see coming until it is too late. I think the rest of these threats are visible enough to prepare against.

- collectivism

- Socialism and big government

- Magnetic field reversal

- Some sort of human-induced disaster. Overpopulation is a very likely driver, but I still see the problem even in a situation with a much smaller human population.Currently, leaning towards some form of social stagnation, eg, a "hydraulic empire". Extinction through total warfare, whether it be a nuclear holocaust or some other form, is a near second.

- Bio-engineered terror/accident

- Nanotech or Biotech terrorism

- Our transition through the pre-Technological Singularity period when our capabilities outstrip our sensibilities.

A) Before 2100
B) 2100 - 2500
C) 2500 - 5000
D) After 5000
E) Inherently unpredictable

A) Divine intervention, coming of a new "heaven on earth"
B) Humans will find a way to adapt/preserve life and the planet
C) Other

Other responses:

- Did you mean habitable by humans? The biosphere will protect itself. Wars and drought and pestilence will cull the herd.

- The humans will kill themselves off, sure. However, the planet will continue. We're just a virus the earth will rid itself of.

- The Earth is a big place. We can make it unpleasant to live on for a while, but we would have a damn hard time making it completely uninhabitable. Maybe a grey goo scenario, but outside of that it is unlikely.There are natural things, like giant asteroid impacts or the sun expanding, that would do it. But they are highly unlikely in any span of time less than geologic. Like, for example, the short two million years we humans have been here.

- If necessary, humans will find a way to adapt/preserve life and the planet.

- What ever humans do the earth will recover over time

- Not a proper negation. I simply believe that the events may happen, not that they will or they won't. If the Earth becomes unsuitable for human habitation, then any of the time periods mentioned would be possible. Some reasons why the Earth might remain habitable include luck or working to avoid causing extinction events.

- the Earth is far more robust that we give it credit for. If global warming is a fact, it will disrupt the species that is creating the warming by reducing its numbers and persuading it to give up carbon generating activities. Earth is intelligent - but does not appear to have identity

- Humans will survive/evolve/mutate. Human civilization as we have it today will not.

- We'll kill off enough of the overpopulated to make earth spacious enough for whoever is left. They may remove themselves when "uploading" becomes feasible.

- Not sure

- both divine intervention and humans adapting

- The planetary environment is a self-correcting system and humans are technologically adaptable.

5. What are the best remedies for survival of the human species?

A) The Technological Singularity
B) Terraforming / colonizing a planet in our solar system
C) Terraforming / colonizing a planet in another solar system
D) Building non-planetary space settlements (asteroids, space stations, etc.)
E) Colonizing an earthlike planet
F) Adapting terrestrial life to survive on other planets / in space
G) Other

Other responses

- All of them, sequentially, in an outward expansion.

- all of the above

- Multiple approaches are essential. Space also may become uninhabitable at times.

- adapting people to live on the otherwise toxic earth; so we eat plastic and breath carbon monoxide, so what?

A) Advancement of technology to support life?
B) Finding natural or supported ecosystem to support life?
C) Other

Other responses

- Porn

- I don't think long-term survival of any species which develops advanced computers is possible, short of a luddite dictatorship or a war that knocks them back to the stone age.

- Developing genuine Earth to orbit launch infrastructure.

- Advancement in general. If we ever stop advancing, we're dead. This advancement must be in every field; technology, medicine, philosophy, law, etc.

- benign AI.

- Both--humans will always need some sort of natural ecosystem to flourish

8) Explain why space settlement should or should not remain a priority.

- It can be fun. Useful things can be found.We have the chance to do it, and to stretch our minds, we should do so.The cosmos call to all.

- Fun!

- "A mans reach should exceed his grasp or what's a heaven for." Browning, I believe.

- The sun will eventually burn out and die. We cannot remain on Earth forever, despite the wording of question 7.

- If we value the continuation of our species, we need to diversify our habitats so that we are not all dependent on the same one.

- Sol will explode sometime. It's a nice fantasy to cling to that we aren't just another species passing to non-existence like dinosaurs.

- Keep us from getting bored

- It should remain a priority if for no other reason than to allow continued social/cultural experimentation. The American Experiment was possible because of the time/geography distance from the established, dominant European cultures. It is difficult to see how a similar "new" experiment could be conducted on Earth today. (Absent the Singularity, that is, which may rewrite ALL the rules.) Testing truly new modes of living requires lots of social elbow room -- something not available on Earth today.

- With easy access to space, dirty industries could be moved off Earth. Besides, the eggs-in-one-basket argument still applies.

- The meek shall inherit the Earth. All the rest of us can lay claim to the Universe. Besides, there is wisdom in "Don't keep all your eggs in one basket."

- It is human nature. Also as contingency in the case of catastrophic event.

- Because it's who God made us to be - explorers

- A future with space settlement is a brighter future with greater opportunity. Expanding beyond earth will create new opportunity for advancement, wealth, and freedom for humanity. Regarding answer to question 3 Earth will eventually become uninhabitable due to lifecycle of the sun, and way beyond that, heat death of the universe, in other words far far beyond year 5000.

- two reasons; a-there will never be absolute certainty that the earth will continue to exist no matter how much control we think we have, and b-spreading out in space is the only way to achieve some kinds of opportunities for progress, and the nesscesary resources

- Expansionism breeds cultural/biological diversity

- Priorities should be made on a personal level and as such based on personal needs and wants. If it is a priority great. If not, who am I to say it should?

- Should: As its been said a billion times before, don't keep all your eggs in one basket.

- Always have a backup plan!

- because you don't put all your eggs in one basket.
because, not to do so implies stagnation, and eventual doom as a species

- First, it will give scientists something to focus on that will probably lead to other discoveries that will help with life on this planet. These discoveries might otherwise not occur if the scientists focused only on this planet. Second, it's inspirational and will motivate people to do science generally. Finally, we can't plan for every eventuality. There is always a non-zero possibility that something will cause Earth to become uninhabitable. Even if that chance is remote, it's based on something inherently unpredictable, and therefore, it would be useful to be able to evacuate some or all of Earth in such an event.

- From the Stromatolite Beach Ark Survey of 2,000,000,000 B.C.:

"8) Explain why land settlement should or should not remain a priority."

- to spread human and life to other planets we'r the only know example of life in ths universe

- Space settlement should be a priority. We can keep Earth intact and habitable. We already have the necessary technology. However, it doesn't mean we will.

- we should not spread a species that has not yet learned how to take care of its own world.

- Basically, all else being equal the more sentient beings the better.

- Survival is an ongoing challenge. There will always be escalating degrees of difficulty in continuing an acceptable existence, whether it is surviving the effects of our own technology, killer asteroids falling from the sky, the death of the Sun, trans-dimensional invasions of malevolent beings, or the eventual heat death of the universe. When humankind learned to perceive the future, we also took on the responsibility of anticipating future survival requirements for our species (as well as life in general) and preparing ourselves as best we can. Maybe in a thousand years, the effort to colonize the nearest suitable extra-solar planet will be trivial, but only because we strive now to figure out how to do it.The human race: Never give up, never surrender.

- Risking extinction is too high a price to pay for saving some money in the budget

- We are running out of resources here, and even if we should find a way to preserve Earth, it is a natural step to move beyond this planet, and expand both physically and scientifically into space.

- Space settlement should be a priority because it'll be fun! It'll be great to "Live amongst the Stars!"

- We're still inherently consumptive - we eat all the resources in our local environment. A global community needs the local resources of an entire solar system. From there we'll need much better skills to harvest the galaxy to feed our hunger.

- The chance to grow and test new forms of government and freedoms

- Variation is the stuff of life. Evolution depends on it, so having humanity spread out to more variable habitats (other planets, orbital colonies, whatever) gives us/evolution more variation to work with.

- easier to build colonies on sea floor or arctic or desert than anywhere in space. lower travel time. space colonies not immune from war, disease or other disasters.

- It's where we belong. It's our destiny.

- The actual need for a space ark seems so remote we should be giving concerns here our full attention to keep earth habitable and protect ourselves from extraplanetary cataclysms

- Space settlement both increases the amount and type of resources available for humans to develop and utilize and diverts much of the competition amongst ourselves for control of planetary resources to exploration and discovery of extra-planetary resources.