Hola.No sé si ésto tiene que ver más con la astronomía o con la meteorología,pero lo incluyo por si alguien le interesa.Si molesta a alguien,que me lo diga y lo borro.Está sacado de:
http://www.space.com/scienceastronomy/solarsystem/death_of_earth_000224.html (http://www.space.com/scienceastronomy/solarsystem/death_of_earth_000224.html)
Before Earth´s oceans ever have a chance to freeze or fry, they might have already dried up and evaporated into space, said James Kasting, a Penn State professor of meteorology and geosciences. Kasting estimates his version of the end is a mere 1 billion years away.
"The sun ... is getting brighter with time and that affects the Earth´s climate," Kasting said. "Eventually temperatures will become high enough so that the oceans evaporate."
And, Kasting said, a cataclysmic finale may come even sooner. As Earth becomes a global desert, carbon dioxide levels are expected to drop. At a certain level, which he and his colleagues say might be achieved in half a billion years, there would not be enough carbon dioxide to support photosynthesis, and most plants would die.
Remaining plants would not be sufficient to support a biosphere, Kasting contends. So while the entire planet might incinerated in a few billion years, or cast off into a deep freeze, it´s possible that life on Earth is already in the sunset years.
"If we calculated correctly, Earth has been habitable for 4.5 billion years and only has a half-billion years left," Kasting said.
Pos hombre, lo podias haber traducido.