"Your opinion is the complete opposite to that of the worlds leading sceintific institutions."
This argument no longer flies. There are numerous peer reviewed articles that cast doubt on AGW. There are thousands of scientists that have backed away and more coming every day.
"Their studies have shown a drop of 11% of growth in Porites colonies on large parts of the great barrier reef over the last 10 years."
What are their measures? Could they eilliminate all other causes? Could they prove that the corals did not have a natural increased growth rate before the 10 year study? Why "a large part" of the barrier reef, if it actually was pH shouldn't it be ALL the barrier reef? Remember a while back when they attributed large areas of coral bleaching to AGW, so what is the explanation for their recovery? Does a pH difference of .1 make a difference in the SPS growth in your tank? It doesn't in mine. These are questions a nonpolitical scientist asks when reading articles, a political person like yourself with an agenda, reads it like passages from the bible.
"But the mechanism by which CO2 heats the planet IS based on well-known, uncontroversial physics and chemistry, so everything else being equal, higher CO2 concentrations will result in a warmer atmosphere."
This is a simplistic statment that does not address many variables. Sugar makes Koolaid sweet, that is an undeniable fact. Howver, to say that putting 2 grains of sugar in a gallon of koolaid makes it twice as sweet as one grain is a pretty subjective claim. CO2 is a trace gas. Man contributes 1/2 of 1% or less of the CO2 emmitted. Their has been no correlations shown. x amount of CO2 does not raise the temp y degrees. Why not, if the relationship is so clear? Obviously, other much more power forces are in play. Then there is the matter of saturation. CO2 is clear, it can only stop so much solar radiation. It is like layering glass together, you will never put enough glass layers together to block all the light.
But the biggest problem and the area that the political supporter do not address, because they do not understand the science of the position they hold, is one of forcings. CO2 can never provide the degree of warming predicted by the models on their own. All climatologist acknowledge this. Water vapor accounts for over 95% of all greenhouse gases. Scientist claim that the effects of CO2 will cause a positive temperature feedback loop. It is an argument of the earths climate sensitivity. It is how they explain a very small amount of CO2, relativly, causing such a huge problem. Basically it states the CO2 will create more water vapor in the atmosphere. Dr Richard Lindzen and Dr. Yong-Sang Choi published a peer reviewed article in July of 2009 showing through observed data that the opposite was true. That it was actually a negative feedback loop and the sensitivity of the earth's climate was low.
http://en.wikipedia.org/wiki/Kirchhoff's_law_of_thermal_radiation
Observing the greenhouse effect in action
The simplest direct observation of the greenhouse effect at work is atmospheric backradiation. Any substance that absorbs thermal radiation will also emit thermal radiation; this is a consequence of Kirchoff's law. The atmosphere absorbs thermal radiation because of the trace greenhouse gases, and also emits thermal radiation, in all directions. This thermal emission can be measured from the surface and also from space. The surface of the Earth actually receives in total more radiation from the atmosphere than it does from the Sun.
The net flow of radiant heat is still upwards from the surface to the atmosphere, because the upwards thermal emission is greater than the downwards atmospheric backradiation. This is a simple consequence of the second law of thermodynamics. The magnitude of the net flow of heat is the difference between the radiant energy flowing in each direction. Because of the backradiation, the surface temperature and the upwards thermal radiation is much larger than if there was no greenhouse effect.
Atmospheric backradiation has been directly measured for over fifty years. The effects of greenhouse gases stand out clearly in modern measurements, which are able to show a complete spectrum.
IR spectrum at the North Pole
Figure 1. Coincident measurements of the infrared emission spectrum of the cloudfree atmosphere at (a) 20km looking downward over the Arctic ice sheet and (b) at the surface looking upwards. (Data courtesy of David Tobin, Space Science and Engineering Center, University of Wisconsin-Madison. Diagram courtesy of Grant Petty, from Petty 2006).
When you look down from aircraft at 20km altitude (Fig 1a), what is "seen" is the thermal radiation from Earth that gets out to that height. Some of that radiation comes from the surface. This is the parts of the spectrum that follow a line corresponding in the diagram to about 268K. Some of that radiation comes from high in the atmosphere, where it is much colder. This is the parts of the spectrum that follow a line of something like 225K. The bites taken out of the spectrum are in those bands where greenhouse gases absorb radiation from the surface, and so the radiation that eventually escapes to space is actually emitted high in the atmosphere.
When you look up from the surface (Fig 1b), what is "seen" is thermal backradiation from the atmosphere. In some frequencies, thermal radiation is blocked very efficiently, and the backradiation shows the temperature of the warm air right near the surface. In the "infrared window" of the atmosphere, the atmosphere is transparent. In these frequencies, no radiation is absorbed, no radiation is emitted, and here is where IR telescopes and microwave sounding satellites can look out to space, and down to the surface, respectively.
The smooth dotted lines in the diagram labeled with temperatures are the curves for a simple blackbody radiating at that temperature. Water vapor has complex absorption spectrum, and it is not well mixed in the atmosphere. The emissions seen below 600 cm-1 are due to water vapor appearing at various altitudes. Carbon dioxide is the major contributor for emission seen between between about 600 and 750 cm-1. The patch of emission just above 1000 cm-1 is due to ozone.
......................................................................................................
Water vapour is the most dominant greenhouse gas. Water vapour is also the dominant positive feedback in our climate system and amplifies any warming caused by changes in atmospheric CO2. This positive feedback is why climate is so sensitive to CO2 warming.
Water vapour is the most dominant greenhouse gas. The greenhouse effect or radiative flux for water is around 75 W/m2 while carbon dioxide contributes 32 W/m2 (Kiehl 1997). These proportions are confirmed by measurements of infrared radiation returning to the Earth's surface (Evans 2006). Water vapour is also the dominant positive feedback in our climate system and a major reason why temperature is so sensitive to changes in CO2.
Unlike external forcings such as CO2 which can be added to the atmosphere, the level of water vapour in the atmosphere is a function of temperature. Water vapour is brought into the atmosphere via evaporation - the rate depends on the temperature of the ocean and air, being governed by the Clausius-Clapeyron relation. If extra water is added to the atmosphere, it condenses and falls as rain or snow within a week or two. Similarly, if somehow moisture was sucked out of the atmosphere, evaporation would restore water vapour levels to 'normal levels' in short time.
Water Vapour as a positive feedback
As water vapour is directly related to temperature, it's also a positive feedback - in fact, the largest positive feedback in the climate system (Soden 2005). As temperature rises, evaporation increases and more water vapour accumulates in the atmosphere. As a greenhouse gas, the water absorbs more heat, further warming the air and causing more evaporation. When CO2 is added to the atmosphere, as a greenhouse gas it has a warming effect. This causes more water to evaporate and warm the air to a higher, stabilized level. So the warming from CO2 has an amplified effect.
How much does water vapour amplify CO2 warming? Without any feedbacks, a doubling of CO2 would warm the globe around 1°C. Taken on its own, water vapour feedback roughly doubles the amount of CO2 warming. When other feedbacks are included (eg - loss of albedo due to melting ice), the total warming from a doubling of CO2 is around 3°C (Held 2000).
Empirical observations of water vapour feedback and climate sensitivity
The amplifying effect of water vapor has been observed in the global cooling after the eruption of Mount Pinatubo (Soden 2001). The cooling led to atmospheric drying which amplified the temperature drop. A climate sensitivity of around 3°C is also confirmed by numerous empirical studies examining how climate has responded to various forcings in the past (Knutti & Hegerl 2008).
Satellites have observed an increase in atmospheric water vapour by about 0.41 kg/m² per decade since 1988. A detection and attribution study, otherwise known as "fingerprinting", was employed to identify the cause of the rising water vapour levels (Santer 2007). Fingerprinting involves rigorous statistical tests of the different possible explanations for a change in some property of the climate system. Results from 22 different climate models (virtually all of the world's major climate models) were pooled and found the recent increase in moisture content over the bulk of the world's oceans is not due to solar forcing or gradual recovery from the 1991 eruption of Mount Pinatubo. The primary driver of 'atmospheric moistening' was found to be the increase in CO2 caused by the burning of fossil fuels.
Theory, observations and climate models all show the increase in water vapor is around 6 to 7.5% per degree Celsius warming of the lower atmosphere. The observed changes in temperature, moisture, and atmospheric circulation fit together in an internally and physically consistent way. When skeptics cite water vapour as the most dominant greenhouse gas, they are actually invoking the positive feedback that makes our climate so sensitive to CO2 as well as another line of evidence for anthropogenic global warming.
---------------------------------------------------------------------------------------------------------------------------------------------------------
I admittedly haven't read the Dr Richard Lindzen and Dr. Yong-Sang Choi paper yet, but quick google search indicates there could be some discrepancies.
http://carboncapturereport.com/cgi-bin/biodb?PROJID=5&mode=viewpersonname&name=dr._richard_lindzen
