Mann writes at LiveScience:
The IPCC reports a likely range of 1.5 to 4.5 degrees Celsius (roughly 3 to 8 degrees Fahrenheit) for this quantity, the lower end having been dropped from 2.0 degrees C in the fourth IPCC assessment. The lowering is based on one narrow line of evidence: the slowing of surface warming during the past decade.
Yet there are numerous explanations of the slowing of warming (unaccounted for effects of volcanic eruptions and natural variability in the amount of heat buried in the ocean) that do not imply a lower sensitivity of the climate to greenhouse gases. Moreover, other lines of evidence contradict an equilibrium climate sensitivity lower than 2 degrees C. It is incompatible, for example, with paleoclimate evidence from the past ice age, or the conditions that prevailed during the time of the dinosaurs. (See this piece I co-authored earlier this year for the Australian Broadcasting Corp. for a more detailed discussion of the matter.)
Yes! That is one of my husband and mine’s favorite cartoons!
I love how there’s only “one narrow line of evidence” which is of course, the only objectively measurable data. All of the assumptions piled onto assumptions that are the confirmation bias dripping proxy paleo climate evidence still says Mann is right. If only those damned pesky empirical observations would play fair.
Michael! For goodness sake man – when your in a hole stop digging!
i think that cartoon should hang on the wall in the office of every researcher in America as a reminder of where theory ends and pure speculation begins..
I think this is their formula: http://blog.stackoverflow.com/wp-content/uploads/then-a-miracle-occurs-cartoon.png
How can you have “unaccounted for effects” in “settled science”?
It’s almost impressive the way they can admit we were right while still calling us idiots for thinking they could be wrong. More than a decade ago I was trying to explain to people that the oceans would act as a heat sink and any GHG effect would take centuries to manifest because of how much heat it would take to raise the oceans’ temperature. Now they say the heat moved to the deep oceans while somehow avoiding the fact that this invalidates all of the models that failed to account for the ocean. It’s like they think heat is some horror movie, evil entity that will lurk in the shadows, biding its time, and then leap out at us if we drop our guard.
Notice how they always say “numerous explanations” for their missing the mark. Yet until the models were shown to be worthless, they would never even entertain the idea that perhaps other factors were influencing the climate.