From Duke University, where they validate what we’ve been saying for quite some time: there’s a divergence between climate models and reality.
Global warming progressing at moderate rate, empirical data suggest
DURHAM, N.C. – A new study based on 1,000 years of temperature records suggests global warming is not progressing as fast as it would under the most severe emissions scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC).
“Based on our analysis, a middle-of-the-road warming scenario is more likely, at least for now,” said Patrick T. Brown, a doctoral student in climatology at Duke University’s Nicholas School of the Environment. “But this could change.”
The Duke-led study shows that natural variability in surface temperatures — caused by interactions between the ocean and atmosphere, and other natural factors — can account for observed changes in the recent rates of warming from decade to decade.
The researchers say these “climate wiggles” can slow or speed the rate of warming from decade to decade, and accentuate or offset the effects of increases in greenhouse gas concentrations. If not properly explained and accounted for, they may skew the reliability of climate models and lead to over-interpretation of short-term temperature trends.
The research, published today in the peer-reviewed journal Scientific Reports, uses empirical data, rather than the more commonly used climate models, to estimate decade-to-decade variability.
“At any given time, we could start warming at a faster rate if greenhouse gas concentrations in the atmosphere increase without any offsetting changes in aerosol concentrations or natural variability,” said Wenhong Li, assistant professor of climate at Duke, who conducted the study with Brown.
The team examined whether climate models, such as those used by the IPCC, accurately account for natural chaotic variability that can occur in the rate of global warming as a result of interactions between the ocean and atmosphere, and other natural factors.
To test how accurate climate models are at accounting for variations in the rate of warming, Brown and Li, along with colleagues from San Jose State University and the USDA, created a new statistical model based on reconstructed empirical records of surface temperatures over the last 1,000 years.
“By comparing our model against theirs, we found that climate models largely get the ‘big picture’ right but seem to underestimate the magnitude of natural decade-to-decade climate wiggles,” Brown said. “Our model shows these wiggles can be big enough that they could have accounted for a reasonable portion of the accelerated warming we experienced from 1975 to 2000, as well as the reduced rate in warming that occurred from 2002 to 2013.”
Further comparative analysis of the models revealed another intriguing insight.
“Statistically, it’s pretty unlikely that an 11-year hiatus in warming, like the one we saw at the start of this century, would occur if the underlying human-caused warming was progressing at a rate as fast as the most severe IPCC projections,” Brown said. “Hiatus periods of 11 years or longer are more likely to occur under a middle-of-the-road scenario.”
Under the IPCC’s middle-of-the-road scenario, there was a 70 percent likelihood that at least one hiatus lasting 11 years or longer would occur between 1993 and 2050, Brown said. “That matches up well with what we’re seeing.”
There’s no guarantee, however, that this rate of warming will remain steady in coming years, Li stressed. “Our analysis clearly shows that we shouldn’t expect the observed rates of warming to be constant. They can and do change.”
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Eugene C. Cordero of San Jose State University and Steven A. Mauget of the USDA Agricultural Research Service in Lubbock, Texas, co-authored the new study with Brown and Li.
Funding came from the National Science Foundation (Faculty Early Career Development Program grant #ATM-0449996 and NSF grant #AGS-1147608) and the National Institutes of Health (#NIH-1R21AGO44294-01A1).
CITATION: “Comparing the Model-Simulated Global Warming Signal to Observations Using Empirical Estimates of Unforced Noise,” Patrick T. Brown, Wenhong Li, Eugene C. Cordero and Steven A. Mauget; Scientific Reports, April 21, 2015. DOI: 10.1038/srep09957
Full paper here: http://www.nature.com/srep/2015/150421/srep09957/full/srep09957.html
That even with Asthma I haven’t had to buy canned air after 1999 I would have to say that these warmist skyfall luddite overpaid smearers of feces on paper couldn’t predict what a clock would say a minute from meow.
The truth here is that we’re supposed to all be more than a decade dead and we haven’t done ANYTHING other than the 1998 CFC bans to stop it. Global warming happened, we fixed it.
Has the billions we’ve poured in made a difference? Nope. Its made the world a little nicer and a little healthier and my water heater is being replaced next year by a closed cycle 240° oil ballast system that’ll cut my power bill by about $55 a month but in the end what they’re selling just isn’t possible.
We’ll lose 90% of our atmosphere before the surface temp rises from pollution alone.
Let me get this straight: isn’t this the sort of conclusion that made you a ‘flat earther’ under a decade ago??
And now where is the discussion that, if ‘natural factors’ can cause ‘hiatuses’ of > 10 years, then presumably their magnitude must be equal to- or greater than the effect of man-made global warming, since if it weren’t, the hiatus couldn’t possibly occur, could it??
Thirdly, where is the discussion of whether plants display Michaelis-Menten-style growth kinetics (for the non-biologists amongst you, MM Kinetics describe how the rates of enzymatically catalysed reactions proceed, namely V(E) = V(max)* [E]*[S]/(K(m) + [S]), where [E] is the concentration of enzyme, [S] is the substrate concentration and K(m) is the Michaelis Menten constant for that reaction and represents that substrate concentration at which reaction rate is 50% of the maximum possible rate V(max)) in response to carbon dioxide (i.e. increasing carbon dioxide stimulates plant growth which returns carbon dioxide to a solid carbon state at a greater rate than before, thus representing a self-correcting mechanism)?
Fourthly, in this ‘big picture’ long term analysis, what was driving big changes before horrible old homo sapiens came along?? Was it the sun?? Was it volcanic ash in the atmosphere?? Was it great fires burning whole continents of forests down?? Must have been something ‘natural’ mustn’t it?? Because we weren’t around to drive it……
There is no big picture from 1850 to the present day: that is just a blip in climate history.
There is, however, a need to secure further grant funding and currently this requires ‘tweaking the revised version of the climate bible to a new politically acceptable format’.
Isn’t it about time that a few George Foxes of quaker radicalism fame confronted the climate church in suitably formidable manners and told them where to take their idolatries, their climate gold, frankincense and myrrhs, their devotionals and their grant-seeking hymn sheets??
The Green Grok (Bill Chameides) weeps.
Brandon,
We have now had two intervals of flat to declining temperature during the period in which you claim that man-made CO2 is the dominant forcing. Together they outnumber the warming years by 2.6 to one (the 52 years 1944-76 plus 1996-present vs. the 20 years 1977-96).
Only the ideological, delusional and bought off could possibly maintain this crazy hypothesis in the face of such irrefutable evidence. You’re worse than tired to hold such an insane opinion.
You still haven’t responded to my evidence that your delusion is false. There is no difference between previous 20 or 30 year-long warming trends and that of the late 20th century. In fact, many have been stronger for longer.
So this really is the last from me. You can’t or won’t respond despite repeated chances, so you’re a hopeless case, as so many have concluded.
Gloria Swansong,
Counting the number of years of decline vs. rise is meaningless unless it’s also tied to the magnitude of the trends. The very fact that the data show temperatures at present ~0.3 K higher than at roughly the same point of the previous hiatus (~1965) really ought to suggest something to someone who understands basic arithmetic.
Here’s another pretty picture:
http://1.bp.blogspot.com/-o4vtAlhwkrI/VTrVEyu5ceI/AAAAAAAAAcs/MuA5KTmbm5I/s1600/HADCRUT4%2B12%2Bmo%2BMA%2BForcings%2Bw%2BTrendlines.png
We can play around with cherry-picked trendline endpoints until the cows come home and “prove” whatever we want in so doing. There’s a better way … calculate continuous linear trends using multiple sampling periods:
http://4.bp.blogspot.com/-LaL4Fv8E0UM/VTrVE1QKtBI/AAAAAAAAAco/znQkNHbJeFE/s1600/HADCRUT4%2BTrend.png
Mind the y-axis scale changes from top to bottom. The take-away message is that the shorter the sampling period, the more dominant the wiggles from internal variability. At present, according to my estimates, CO2 forcing only exceeds historical bounds of internal variability over something between 240 and 360 month time scales. At 480 month time scales, CO2 at present levels and rate of change is pretty clearly dominant.
Hmmm, may I quote you on that next time richardscourtney goes nuclear on me for being egregiously insulting to you?
Hint: look at the slope of the cooling trends. Is the temperature in 2014 higher or lower than in 1880. How did it get there if all the periodic trends are always the same?
I’ll believe it when I don’t see it.
…. annnnnd here I was thinking that science wasn’t a popularity contest. So much for THAT myth!
http://hockeyschtick.blogspot.com/2010/01/climate-modeling-ocean-oscillations.html
Gloria this tells the whole story. AGW theory is a scam which will meet it’s demise before this decade is out.
Gloria I am in complete agreement with you and I have all of the data to back it up with .