Expert Predicts World May End in Half a Billion Years

This is an attempt to predict the time that it will become impossible to inhabit the Earth on the basis of what is known about how the sun will slowly become brighter. 

I am uncomfortable in the use of the Venus example as an example of runaway green house effect.  I simply believe that to be an error that needs to be challenged.  The arguments in favor of that theory rested on a stack of assumptions that were tortured and should be viewed as highly speculative.

What we have is a planet whose surface rock is very hot.  If it were not, it would be happily cooling the atmosphere.  It is not.  Yet 900 degrees F rock is normally associated with recently molten rock such as lava which starts out at temperatures around twice that.

As I have posted in the past, the proposition that Venus was recently produced by Jupiter as ejecta must be considered.  At the moment it is just as improvable unfortunately, but it also a simple solution to the problem whereas presuming Venus been produced around the same time as Earth and having a similar history is fraught with several things working together to culminate in the present near molten planet. (The red spot is I suspect the scar of the creation of Venus)

To be more specific, imagine snowball earth receiving enough solar radiation to produce the dense atmosphere and near molten surface we presently see.  This is nonsense.  On top of that, by impacting comets into Venus, it is possible to deliver the water and ammonia needed to replicate Earth like conditions.  I suspect that we will get that job after we are finished with terraforming Earth.

So let us get past Venus.  Throw out the forced presumptions caused by making Venus work and we have a far different picture.  To start with, the Earth’s ability to resist the run away green house effect may well be grossly underestimated.  On top of that fully modern man is arriving on Earth in the next generation or so.  I think we can design and put in place orbiting sun shades that will be splendid at reducing any overheating.  This all means that the good professor’s estimate is the least we can expect.  Another couple of generations and we should also be able to manage any external risks from impacts.

So yes, nothing will really ever happen to disturb our developing paradisio.

Forget Mayan 2012 prediction, expert says the world ends in 500 million years

By Terri Theodore, The Canadian Press | The Canadian Press – 12 hours ago

http://ca.news.yahoo.com/forget-mayan-2012-prediction-expert-says-world-ends-091007928.html

VANCOUVER - Are you sweating over recent dire predictions that the end of the world is upon us?

Relax, because according to one expert, we have at least 500 million years to worry about the problem.

Colin Goldblatt is confidently making plans for late December, despite the fact the Mayan calendar runs out Dec. 21, 2012.

The calendar is the basis for the 2009 catastrophe movie 2012, which sees the Earth battered by solar storms, along with unprecedented volcanic eruptions and earthquakes.

But Goldblatt, a professor at the University of Victoria's School of Earth and Ocean Sciences, believes science and not science fiction will reveal the real apocalyptic end to life and Earth.

His theory hinges on what scientists know about the atmosphere, geology and other planets to make a more accurate prediction.

"No, the end of the world is absolutely not near," he stated confidently in an interview. "We can actually say that it's not going to happen for another 500 million, or maybe a billion years."

Goldblatt believes a "runaway greenhouse" effect will be the true end to life on Earth.

He will present his theory, The Physics and Chemistry of the Apocalypse: Runaway Greenhouses, during a seminar at the University on Tuesday.

When the Earth was formed, the sun was about 30 per cent less bright than it was now and as it gets brighter, the Earth's atmosphere will become "optically thick," he said.

It means, Goldblatt said, that only the top of the atmosphere can radiate head out into space, while Earth's surface gets very hot.

"It's like turning the taps on in the bath, but putting the plug in. The bath will get so full it will overflow, and in the same way if we have an optically thick atmosphere, the surface will just keep getting hotter and hotter and hotter, until the entire ocean evaporates.

"That certainly won't be healthy for us," he added.

The heat, which would reach about 1,100 C, would be enough to do away with life on Earth, he said.

"Everything would be truly cooked."

Goldblatt said scientists believe the same thing happened on the planet Venus about two to four billion years ago.

Of course, he said that wouldn't take into account nuclear war or massive asteroid impacts in the next half billion years that could cut short that prediction.

Last year, California preacher and doomsday prophet Harold Camping predicted the end of the world would be in May and when that deadline passed, he said Earth's obliteration would actually be in Oct 21, 2011.

While the Mayan calendar runs out Dec. 21 this year, experts on the Mayan culture have since disputed that the culture predicted the end of the world.

None of those predictions fazes Goldblatt.

"I'm happy to book a flight to go back and see my folks next Christmas," he chuckled.

"There are other things that we should worry about. We should worry about the effect we have the environment...We should worry about how we behave to our neighbours."