Young Sun Paradox Says Life Should Not Have Happened?

Yep, you read that right. IO9 posted an article that for all intents says that due to the energy output of Sol's when it was much younger could not have warmed the Earth enough to have liquid water and there for making life all but impossible. But since Earth teems with life, there is a bit of a paradox. The young sun paradox.

This is approximately how it works. In the early days of the solar system, the sun's output was only about 70 of today's levels. This means that there was not enough energy to maintain a liquid water environment on Earth and absolutely no running water on Mars which we know is NOT the case. This paradox was first put forward in the 70s by the likes of Carl Sagan.

From the article:

• A Penn State research team .. has created a new computer model that can simulate the Sun's evolution under various different starting condition. What they're searching for is the right combination of starting elements and internal conditions that could support an old, largely disregarded explanation: that the Sun was once more massive than it is now, and a fierce solar wind shrunk it to its present size.

How much bigger....anywhere from 2% to 10%  larger than it's present size.  That would mean that despite a lower output, the additional size means that the energy reaching Earth and Mars was pretty much the same.  

Check out the article here