2 ms·
Right. But it is a possible mechanism that has nothing to do with the current thickness of the atmosphere or distance to the sun. Once upon a time, Venus wasn't
by drjesusphd 10y ago
Right. But it is a possible mechanism that has nothing to do with the current thickness of the atmosphere or distance to the sun. Once upon a time, Venus wasn't so bad either.
Is James Hanson not "serious"? I agree that the consensus view seems to be that this is still an unlikely scenario.
http://news.nationalgeographic.com/news/2013/13/130729-runaway-greenhouse-global-warming-venus-ocean-climate-science/ http://news.nationalgeographic.com/news/2013/13/130729-runaw...
As far as numbers go, I'm not a climate scientist, but I have done these kind of calculations before. If I figure out the tipover temperature, I'll post it.
- nonbel 10y agoIf I understood correctly, for that model they varied the "surface temperature" of a 1-dimensional object under constant illumination by hard-coding it, rather than simulating an increase in insolation or pressure to cause warming: "When surface temperature is below the critical point temperature (647K), the surface pressure is set as the saturation vapour pressure for that surface temperature, and the tropospheric temperature– pressure structure is taken directly from the saturation vapour pressure curve. Where the surface temperature exceeds the critical point temperature, we prescribe surface pressure as 2.6×107 Pa, corresponding to Earth’s surface water reservoir." http://www.nature.com/ngeo/journal/v6/n8/full/ngeo1892.html http://www.nature.com/ngeo/journal/v6/n8/full/ngeo1892.html So first, they do increase the thickness of the atmosphere, and the increased surface temperature would come from a possible future sun (not adding CO2) I guess. Second, I wouldn't put much stock in such simplified models.