Originally Posted by Troels

I google'd and got this:
http://www.aip.org/history/climate/Venus.htm

AIP is a reliable source or biased?

Anyway, main points are that Venus's atmosphere is causing the extremely high temperature? Right?
An atmosphere that mainly consists of CO2 and prevents any heat of leaving the atmosphere.

"Perhaps Venus had once enjoyed a climate of the sort hospitable to life, but as water had gradually evaporated into the warming atmosphere, followed by CO2, the planet had fallen into its present hellish state? In a 1971 paper, James Pollack argued that Venus might once have had oceans like Earth's It seemed that such a "runaway greenhouse" could have turned the Earth too into a furnace, if the starting conditions had been only a little different.(8*)"

But then I read this:

"Hart's calculations were riddled with untested assumptions, and many scientists denied that our situation was so extremely precarious. (Later calculations showed they were right ? a Venus-type runaway on our planet is scarcely possible, even if we burn all available fossil fuels.)"

What the docu was saying was that human caused emission of CO2's part of the greenhouse effect was miniscule on earth. So is that incorrect?