This is factually incorrect. What was quoted is the climate sensitivity (how much the temperature goes up if CO2 doubles). Here the error bars were brought in from four years ago. There are too many variables to accurately predict the temperature for 2100 (e.g. technological progress, economic growth, CO2 and methane feedback mechanisms). But "Error Reduced in Climate Sensitivity" doesn't make a sexy headline, does it?
Problem #1: They emphasize the upper bound, not the lower bound or the size of the uncertainty. This is wide-spread and is partly caused by what scientists say and partly by media distortion.
Problem #2: Most of these "estimates" are actually "projections", not "predictions". The models they are using to generate them haven't been proven to match reality. In fact many of them have been disproven. No matter, there's always another model lurking somewhere.
Problem #3: Physical observations and measurements do not support sensitivities this high. The typical answer, when asked how this can be reconciled, is that there are feedbacks which cause the effect to be exaggerated. Unfortunately, these feedbacks are usually claimed to be processes which are poorly understood. Why assume poorly understood processes would have a positive feedback effect, rather than a negative one?
The whole thing is fraught with elements which are "factually incorrect". However it usually doesn't stop the alarmist claims, which frequently are not supported by the science.
What's with the double post, Ron?
Problem #2: Most of these "estimates" are actually "projections", not "predictions". The models they are using to generate them haven't been proven to match reality. In fact many of them have been disproven. No matter, there's always another model lurking somewhere.
Problem #3: Physical observations and measurements do not support sensitivities this high. The typical answer, when asked how this can be reconciled, is that there are feedbacks which cause the effect to be exaggerated. Unfortunately, these feedbacks are usually claimed to be processes which are poorly understood. Why assume poorly understood processes would have a positive feedback effect, rather than a negative one?
The whole thing is fraught with elements which are "factually incorrect". However it usually doesn't stop the alarmist claims, which frequently are not supported by the science.
Just don't let the facts get in the way, or what is understood, and what is not understood stand in the way of an Alarm.
George Orwell