http://www.climate4you.com/ClimateAndClo...
Well the IPCC premise is, that the small amount of warming created by CO2, would allow a much higher amount of water vapor to be contained in the atmosphere, which would cause more warming and more water vapor and so on.
But it didn't happen and was not likely to happen, a look into our history would tell us so, in the Eemian period it was much warmer, but run away water vapor heating did not happen.
However methane is a much more dangerous gas, and some scientist theorize that the reason for ice ages to end so abruptly is that sea levels lower to an amount that all the methane in the arctic ocean and elsewhere in hydrates can no longer be contained and become released and drive global warming.
By the way there is no greenhouse effect on Venus, it is thermus flask effect, Venus has an 118earth day long day, during the day the temp is 737K during the night it is also 737K, indicating that due to the extreme dense atmosphere no solar heat comes in, and no heat is radiated to space, Venus is hot because the heat generated when the planet formed has not been allowed to cool.
A runaway greenhouse effect is a process in which a net positive feedback between surface temperature and atmospheric opacity increases the strength of the greenhouse effect on a planet until its oceans boil away.[1][2] An example of this is believed to have happened in the early history of Venus. On the Earth, the IPCC states that "a 'runaway greenhouse effect'—analogous to Venus—appears to have virtually no chance of being induced by anthropogenic activities."[3]
Other, less catastrophic events, that nonetheless can produce a large climate change sometimes are loosely called a "runaway greenhouse" although it is not an appropriate description. For example, it has been hypothesized that large releases of greenhouse gases may have occurred concurrently with the Permian-Triassic extinction event[4][5] or Paleocene–Eocene Thermal Maximum. Other terms, such as "abrupt climate change", or tipping points could be used when describing such scenarios.[6]
On much longer timescales, such processes can potentially spell the end of life on Earth due to the gradual increase in brightness of the Sun as it expands into a red giant in about five billion years.
Your sounding more and more like an Alarmist. When you become published, let me know.
Shouldn't the tipping point have been reached? Pre 1800's maybe?
Anyway the chill bumps as to someone knowing what is foreseen in a silicon crystal ball is definitely SFY material.
the positive feedback element is methane.
methane is 4x more potent as a green house gas than carbon. Where will the methane come from?
methane is trapped in ancient ice...dating back to the ice age. scientist drill tubes of ice and can date the layers of air bubble back to the ice ages. they can log when the Earth was cooler and when it was warmer, logging the snow layers on the ice and the carbon/methane bubble count in each layer.
that ice is being released in an amplified, or in positive feedback state...
methane is trapped in ice. the planet becomes warmer as we *burn *trees= *carbon released *shade destroyed=desertification increased=island heat effect. the ocean absorbs the carbon and the heat. ice reflects the rays-but as the positive feedback loop speeds up there is less ice to reflect. the ocean is now warmer &warmer, and melts sea ice.
I won't ignore the excess burning of fossil fuels- teaming with dirty carbon.
the sea ice releases the methane=more green house gases have just been released 4x greater speed than just burning carbon soaked trees.
as there is more heat-more evaporation=more desertification=hotter earth (less reflective) surfaces.
think of a glass full of mostly ice with some water, sitting in the sun on a warm day. at one point in time, the ice will melt so much that it will now take Longer to bring to bring that ice back to frozen (by bringing it to a freezer) than it will for it to melt as it sits in warming water.
but considering that in the past when co2 levels were 20 times higher and this quaint little runaway green house effect theory didn't happen then we can safely say that nature has already tested this theory for us and it's about as real as a fairy tale.
My understanding of the runaway greenhouse effect if it would occur on Earth uses a phase diagram of water.
Phase diagram for H2O - http://chemwiki.ucdavis.edu/@api/deki/files/2657/=Phase_Diagram_H2O.jpg
Phase diagram for CO2 - http://chemwiki.ucdavis.edu/@api/deki/files/2663/=Phase_Diagram_CO2.jpg
Mars has an average starting temperature of 240k therefor water vapour on Mars wouldn't go into the liquid form before solidifying when condensation occurs. Earth's average temperature is 288k. As vapour pressure increases eventually it meets a wall where it condenses and it rains for example. Vapour on a planet like Venus would never condense as the curve for the relation between vapour pressure and temperature does not meet the 100% humidity line.
http://www.unc.edu/~rchristm/Water%20Vapor%20Pressure%20vs%20Temp.jpg
Can you please explain how a runaway greenhouse effect could occur on Earth, if at all. The tropopause, which is the coldest part of the atmosphere and is the wall between tropospheric water vapour concentration and stratospheric water vapour concentration, has much to do with it as well the lecture stated.
http://www.youtube.com/watch?v=g6ljuqucaIg
