Terra biosphere mass extinction

[Orion1]

Even if Earth escapes incineration in the Sun, its water will be boiled away and most of its atmosphere would escape into space. In fact, even during its life in the main sequence, the Sun is gradually becoming more luminous (about 10% every 1 billion years), and its surface temperature is slowly rising. The increase in solar temperatures is such that in about a billion years, the surface of the Earth will become too hot for liquid water to exist, ending all terrestrial life.

Certainly, with the 10% increase of solar luminosity over
the next 1Gy (see previous section), it is clear that Earth
will come to leave the Habitable Zone already in about a billion years
time, since the inner (hot side) boundary will then cross 1 AU.

Professor James Kasting, at Pennsylvania State University, calculates that the Earth's oceans will disappear in about one billion years' time, due to increased temperatures from a brightening Sun. However, well before the planet is left as an arid desert, the level of carbon dioxide in the atmosphere will be too low to support plant life, destroying the foundation of the food chains.

Barophilic marine microbes have been found at more than 10 km depth in the Marianas Trench...Culturable microbes have been found in the Earth's upper atmosphere as high as 41 km.

Biologist E. O. Wilson estimated in 2002 that if current rates of human destruction of the biosphere continue, one-half of all species of life on Earth will be extinct in 100 years. More significantly the rate of species extinctions at present is estimated at 100 to 1000 times "background" or average extinction rates in the evolutionary time scale of planet Earth.

Is Terra's biosphere dying?
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Reference:
http://www.youtube.com/watch?v=x2SNKvVOrMk"
http://en.wikipedia.org/wiki/Sun#Life_cycle"
http://arxiv.org/PS_cache/arxiv/pdf/0801/0801.4031v1.pdf"
http://news.bbc.co.uk/1/hi/sci/tech/specials/washington_2000/649913.stm"
http://en.wikipedia.org/wiki/Biosphere#Extent_of_Earth.27s_biosphere"
http://en.wikipedia.org/wiki/Extinction#Modern_mass_extinction"

 

[Andre]

Well basically, most are unverifiable speculations approaching philosophy. I doubt about the habitable zone if it's based on a radiation model only, neglecting convection/advection of heat. If there is more sunlight, you would expect the Earth just evaporating more water and thus having more clouds, which is increasing reflextivity, which lowers the absorbted radiation and hence keeps the temperature lower. But the end must be somewhere.