In direct answer to the question: It shows that they definitely are not certain. It shows that their theory has fallen apart and they have no explanation, but they still keep on persevering anyway. But in their own minds they are certain, they don't know why, but they are certain.
How much money did the world spend on this report? And all they can come up with is definitely indefinite statements.
It is worse than that. We frequently get quotes here that this has been known since the days of Arrhenius. I don't think we have made much progress since.
Uncertainties have not been narrowed. In fact, AR5 now does not quote a central estimate for climate sensitivity just a range. This is a backward step from AR4.
When we compare climate science with say particle physics and we note the Tyndall experiment with a metal tube and compare that to the Large Hadron Collider we can easily spot the winners. Does the future of the planet depend on the discovery of the Higgs Boson? Will the planet be affected by Climate Change? Strange priorities.
Real world experiments are sadly lacking in the climate arena. Has anyone shown the greenhouse effect working in a real atmosphere yet? Experiments seem to be for the computer gamer set. They run programs on other people's data and call it an experiment.
Let's see what they say about the pause.
Is there a pause?
If there is a pause, what is causing it?
- the Sun?
- the Asian brown cloud?
- PDO?
- AMO?
- is carbon dioxide effect approaching the saturation point? If that is what is happening, it would explain the pause, and also past warming.
and
If carbon dioxide sensitivity is low, what caused past warming?
<:< If carbon dioxide sensitivity is low, what caused past warming?> The Sun.>
Wrong.
http://www.woodfortrees.org/plot/gistemp...
Sounds like zero progress at all to me. The range of uncertainty remains exactly the same.
Obviously for those who have some level of scientific education, until the range of uncertainty in your projections,can be narrowed/refined then you have made no significant advances.
The Charney Report in 1979 was a general summary of climate science at that time. It had stated the following about climate sensitivity: "We estimate the most probable global warming for a doubling of CO2 to be near 3C with a probable error of +/-1.5C." They go on to explain the large range as due to uncertainties like the exchange of heat between atmosphere and oceans.
Now fast forward 34 years later to today and the latest from climate science (i.e. the IPCC AR5 report) gives us the following: "Equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C."
Couple of questions:
1. What uncertainties have been slayed over the past 34 years to go from "most probable" to "likely".
2. How much time and effort has been expended to update that 1979 climate sensitivity estimate?
3. What is the temperature trend versus the official climate sensitivity range over the past 10, 20, 30, 50, 100, 150 years?
4. What will be the state of the art climate sensitivity estimate in 2047?
