Climate Sensitivity to Carbon Dioxide Concentrations The world is being constantly bombarded with the message that 97% of scientists “Believe” in Global Warming and that man has contributed to that warming. Let us breakdown that message. The world has warmed up about .8C since the Little Ice Age; so yes, it has warmed and yes, man has influenced climate by deforestation, irrigation, desertification, urbanization(UHI), real air pollution and the effect of CO2. Carbon Dioxide is a Green House Gas in theory but in the atmosphere the back radiation spectrum is dominated by existing water vapor and the amount of additional back radiation declines logarithmically with additional CO2 so the actual effect of more CO2 is unknown. The accepted effect of doubling CO2 concentration is about 1C max.
These parts of the message should have near universal agreement. (maybe even 97%) So where are the important differences in opinion?
1. How sensitive is the Climate to changes in CO2 concentration?
2. Is the positive feedback/amplification theory real and can it cause large changes in temperature?What about negative feedbacks? What if feedbacks are net negative as would be expected in a natural long term system?
3. Can CO2 warm the climate enough to cause catastrophic events?
4. What is a reasonable probability of this occurrence?
The measurements from the three world satellite temperature sets and 4 balloon sets show an increasing divergence with the projections from the Climate Models. The assumptions that have been plugged into the Models appear to massively overestimate the effect of changes in CO2 concentration on temperatures. This is most noticeable in the tropics where the models and theory say CO2 should cause the most warming (see http://tinyurl.com/me5jlcd ) The temperature of the world has shown very little increase for over 19 years now which is close to the length of the previous warming period despite a rapid rise of over 40% in CO2 concentration.
There has been no increase in humidity which was theorized to massively amplify the temperature increase. (actual decrease -see graph)
The temperatures are now so far outside of the model projections (in the less than 5 % probability range) that it is now very unlikely that CO2 concentration is the primary driver of climate. There are now 14 new peer reviewed published papers that estimate lower climate sensitivity to changes in CO2 and many sensitivity estimates are now below the estimated safe limit of 2 C.
Unfortunately belief in Carbon Dioxide as the control knob of climate has become less of a scientific issue and more of a tool which is being used for political benefit.