There are a lot of possibilities.
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Some talk in a general
way about increasing levels of pollution ending human life. |
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Others worry about
a virus or bacteria that is immune to all treatments. |
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The nuclear powers
in the world (Britain, China, France, India, Israel, North Korea, Pakistan, USA, etc.) have a sufficient number of warheads
to raise the radiation level to an untenable degree. If World War III starts and goes nuclear, there may well be a sufficient
number of bombs exploded to make the Earth unlivable for humans. The earth itself won't end from this cause, but the human
race might. Cockroaches will probably survive almost any level of radiation, and be the "seed" that may evolve into the next
"intelligent" species -- in 100 million years or so. |
But there are two inevitable, naturally occurring, but rare events that have the potential to cause the end of
all life on earth:
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Sometime in the future,
a large asteroid will head on a collision trajectory towards earth. Scientists at the Near Earth Asteroid Tracking project
at NASA's Jet Propulsion Laboratory estimate that there are between 500 and 1,000 large near-Earth objects which have
a diameter of 1 kilometer (0.6 miles) or more. Scientists identified 15 to 20% of the total by mid-1999. Scientists in tracking
stations in California, Massachusetts and Arizona expect to locate 90% of the biggest near-Earth objects by the year 2010.
2 If one of these asteroids is not pulverized and scattered, or deflected, it has the potential to collide with
earth and to wipe out most of humanity. The rock may come next month, or may be delayed for tens of millions of years. But
it is coming! Scientists estimate that there is between once chance in 1,000 and one chance in 10,000 that a "doomsday" asteroid
collision will head towards earth during the 21st century. A web site maintained by the University of Pisa
in Italy collates the latest information. 3 |
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The sun will not last forever.
In about 5 billion years, it will expand into a red giant, and engulf the Earth. I am personally not too worried about this. |
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