Caltech Scientists Predict Greater Longevity for Planets with Life – Caltech.
The paper is:
“Atmospheric pressure as a natural regulator of the climate of a terrestrial planet with biosphere,” by King-Fai Li, Kaveh Pahlevan, Joseph L. Kirschvink, and Yuk L. Yung
…and its abtract is here at the “Proceedings of the National Academy of Sciences.” The chief researcher is King-Fai Li, whose publications page is here and well worth a LOOK…
Basically the pressure of an atmosphere enhances the IR-absorbing spread of carbon dioxide molecules, which is how they trap heat so efficiently on Venus, and apparently how a miniscule 380 ppm of CO2 on Earth plays such a key-role on Earth, but 950,000 ppm on Mars isn’t so effective. If the total nitrogen – some 78% of the atmosphere – declined with the rise in solar insolation, then Earth’s average temperature would remain more stable over the next 2.3 billion years compared with previous models (eg. Lovelock or Caldeira & Kasting.) By the end of that period, when a runaway greenhouse finally kicks in, the surface pressure has dropped to ~0.1 of today. So just how ‘habitable’ Earth remains is a different question. Over such a long-span then life would no doubt adapt, but a luckless Time-Traveller might be a tad short of breath.
Another atmospheric processes guru involved in the paper is Joe Kirschvink, whose webpage is a rewarding visit for all who want to dig deeper. He has papers online about Enceladus and the ALH84001 Martian meteorite which maybe had microfossils.