Den stora tråden om global uppvärmning/växthuseffekten

Att någon skriver "Here you’ll find polar bear science without advocacy, fearmongering or spin. " är ju inte detsamma som att så är fallet. Tvärtom är sådant en rejäl varningssignal. Den som känner behov av att tala om hur opartisk och seriös den är är ofta precis motsatsen.

In the early twenty-first century, satellite-derived tropospheric warming trends were generally smaller than trends estimated from a large multi-model ensemble. Because observations and coupled model simulations do not have the same phasing of natural internal variability, such decadal differences in simulated and observed warming rates invariably occur. Here we analyse global-mean tropospheric temperatures from satellites and climate model simulations to examine whether warming rate differences over the satellite era can be explained by internal climate variability alone. We find that in the last two decades of the twentieth century, differences between modelled and observed tropospheric temperature trends are broadly consistent with internal variability. Over most of the early twenty-first century, however, model tropospheric warming is substantially larger than observed; warming rate differences are generally outside the range of trends arising from internal variability. The probability that multi-decadal internal variability fully explains the asymmetry between the late twentieth and early twenty-first century results is low (between zero and about 9%). It is also unlikely that this asymmetry is due to the combined effects of internal variability and a model error in climate sensitivity. We conclude that model overestimation of tropospheric warming in the early twenty-first century is partly due to systematic deficiencies in some of the post-2000 external forcings used in the model simulations.

It has been posited that the differences between modelled
and observed tropospheric warming rates are solely attributable
to a fundamental error in model sensitivity to anthropogenic
greenhouse gas increases 28 . Several aspects of our results cast doubt on the ‘sensitivity error’ explanation. First, it is difficult
to understand why significant differences between modelled and
observed warming rates should be preferentially concentrated in
the early twenty-first century (see Fig. 2). A fundamental model
sensitivity error should be manifest more uniformly in time. Second,
a large sensitivity error should appear not only in trend behaviour,
but also in the response to major volcanic eruptions 46 . After removal
of ENSO variability, however, there are no large systematic model
errors in tropospheric cooling following the eruptions of El Chichón
in 1982 and Pinatubo in 1991 15 .

En epokgörande publicering. Vad finns egentligen kvar om klimatmodellerna inte stämmer längre? Bara en teori, som utan modeller måste bevisas med faktisk uppvärmning (som är högst beskedlig för närvarande).

Här följer ett gästinlägg av professor Gösta Pettersson med nya resultat som ger svar på kritik framförd i ett par blogginlägg av professor Mats Almgren. Gösta Pettersson visar att hans enkla temperaturberoende boxmodell kan förklara både bombkurvan och Keelingkurvan inklusive El Niñofluktuationerna. Vid sidan av de svagheter i Mats Almgrens kritik som Gösta Pettersson tar upp här tog jag upp andra svagheter i ett tidigare blogginlägg.