"Reasons for the apparent pause in the rise of global-mean surface air temperature (SAT) after the turn of the century has been a mystery, undermining confidence in climate projections"which is, in effect, a stark admission of undermining confidence in the alleged 95% IPCC confidence in climate model predictions, alone due to the myriad of excuses why none of the IPCC climate models predicted the "pause."
In response, the paper offers excuse #55 for the 18-26 year "pause" of global warming: Pacific trade winds accelerating & decelerating. According to the authors, deceleration of natural Pacific trade winds from 1980-2000 added 0.11°C to the 1980s global warming, and 0.13°C to the 1990's warming [which the IPCC blamed >100% on your CO2 emissions instead]. This was allegedly followed by an acceleration of the same Pacific trade winds in the 2000s, causing a global cooling effect of -0.11°C. Note the claims in this paper are entirely from falsified climate models, not observations.
Thus, according to these questionable modeling results, part of the accelerated warming 1980-2000 was natural from weakened trade winds [previously attributed to >100% anthropogenic causes], followed by all of the alleged anthropogenic + natural warming eliminated by strengthened trade winds.
Potential problems with this excuse include:
1) The alleged natural trade wind cooling of -0.11C since 2000 is not enough to reverse the 0.11C + 0.13 = 0.24C warming allegedly from slowed trade winds from 1980-2000, and far less than required to explain the "pause" of all global warming including any anthropogenic contributions for the past 18+ years.
2) Seven years ago, we were told the opposite: slower (not faster) trade winds caused ‘the pause’
3) The models have been falsified at confidence levels exceeding 95%, thus this modeled output is likewise falsified.
4) According to RSS satellite data, the globe warmed ~0.37C from 1980-2000, yet this paper claims 0.24C of the global warming during that period was from a natural weakening of trade winds, thus 65% of the 1980-2000 global warming would be natural, not anthropogenic!
4) According to RSS satellite data, the globe warmed ~0.37C from 1980-2000, yet this paper claims 0.24C of the global warming during that period was from a natural weakening of trade winds, thus 65% of the 1980-2000 global warming would be natural, not anthropogenic!
Contribution of natural decadal variability to global warming acceleration and hiatus
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- Nature Climate Change 4, 893–897 (2014) doi:10.1038/nclimate2355
Reasons for the apparent pause in the rise of global-mean surface air temperature (SAT) after the turn of the century has been a mystery, undermining confidence in climate projections1, 2, 3. Recent climate model simulations indicate this warming hiatus originated from eastern equatorial Pacific cooling4 associated with strengthening of trade winds5. Using a climate model that overrides tropical wind stress anomalies with observations for 1958–2012, we show that decadal-mean anomalies of global SAT referenced to the period 1961–1990 are changed by 0.11, 0.13 and −0.11 °C in the 1980s, 1990s and 2000s, respectively, without variation in human-induced radiative forcing. They [trade winds] account for about 47%, 38% and 27% of the respective temperature change. The dominant wind stress variability consistent with this warming/cooling represents the deceleration/acceleration of the Pacific trade winds, which can be robustly reproduced by atmospheric model simulations forced by observed sea surface temperature excluding anthropogenic warming components. Results indicate that inherent decadal climate variability contributes considerably to the observed global-mean SAT time series, but that its influence on decadal-mean SAT has gradually decreased [in models] relative to the rising anthropogenic warming signal.
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