Biosphere countdown...
Hi All
In their seminal 1992 paper Kasting and Caldeira give the biosphere about ~ 1.0 Gyr ro go, perhaps shorter, based on loss of CO2 as the Sun increases in luminosity. Von Bloh et al give it a bit less for geodynamic reasons...
http://www.pik-potsdam.de/~bloh/abstracts/franck2000/welcome.html
...an older article but well worth a read. Would be interested in your view, Nick.
Adam