Atmospheric pressure and CO2 concentration of potential habitable planet HD40307g

HD40307g is the closest potentially habitable planet discovered today orbiting a K2V star and will be a prime target for future TPF-like missions if its existence is confirmed. Although the atmosphere of HD40307g should be denser and contain more CO₂ judging from the amount of radiation it receives from its star, it is unknown how dense and how much CO₂ the planetary atmosphere should have. Thus more knowledge on its atmosphere is useful. For HD40307g to have Earth-like climate (288 K global mean surface temperature), we obtain the following combination of atmospheric pressure and CO₂ mixing ratio: (1) 10-bar+3% CO₂; (2) 5-bar+10% CO₂; (3) 3-bar+30% CO₂.