Last week, an article came out in Scientific American, titled "The “Pause” in Global Warming Is Finally Explained". It is based on a paper authored by Byron A. Steinman, Michael E. Mann, and Sonya K. Miller that is dutifully pay-walled in Science Magazine.
The abstract says:
The recent slowdown in global warming has brought into question the reliability of climate model projections of future temperature change and has led to a vigorous debate over whether this slowdown is the result of naturally occurring, internal variability or forcing external to Earth’s climate system. To address these issues, we applied a semi-empirical approach that combines climate observations and model simulations to estimate Atlantic- and Pacific-based internal multidecadal variability (termed “AMO” and “PMO,” respectively). Using this method, the AMO and PMO are found to explain a large proportion of internal variability in Northern Hemisphere mean temperatures. Competition between a modest positive peak in the AMO and a substantially negative-trending PMO are seen to produce a slowdown or “false pause” in warming of the past decade.
Both of these oscillations are considered natural, and nothing to do with the anthropogenic greenhouse gases. The paper authors strongly suggest that “will likely reverse…adding to anthropogenic warming in the coming decades.”, and yet they could not be bothered to create a precise timeline of when this is going to happen.
Source: Scientific American |
Michael Mann goes on to say about the paper “suggest that right now we’re near the peak negative excursion, and very close to a turning point,”. What he does leave out in his "the end is nigh" rhetoric, is that by 2020, if the hiatus continues, the CMIP5 models are 99% falsified.
Source: Doug McNeall |
1/8 Did we expect the #slowdown in warming of the Earth’s surface in the last ~15 years (aka the #hiatus, aka the #pause)?
— Tim Osborn (@TimOsbornClim) March 2, 2015
And, yet, 6 years ago Kevin Trenberth was discussing what exactly?
The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't. The CERES data published in the August BAMS 09 supplement on 2008 shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate.Better yet, how about Phil Jones from the very same CRU as Tim Osborn that same year?
That said there is a LOT of nonsense about the PDO. People like CPC are tracking PDO on a monthly basis but it is highly correlated with ENSO. Most of what they are seeing is the change in ENSO not real PDO. It surely isn't decadal. The PDO is already reversing with the switch to El Nino. The PDO index became positive in September for first time since Sept 2007.
Tim, Chris,
I hope you're not right about the lack of warming lasting
till about 2020. I'd rather hoped to see the earlier Met Office
press release with Doug's paper that said something like -
half the years to 2014 would exceed the warmest year currently on record, 1998!
Still a way to go before 2014.
I seem to be getting an email a week from skeptics saying
where's the warming gone. I know the warming is on the decadal
scale, but it would be nice to wear their smug grins away.
Nice post. Reddit ready.
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