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Post by magellan on Feb 15, 2015 19:08:47 GMT
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Post by sigurdur on Feb 15, 2015 20:09:55 GMT
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Post by sigurdur on Feb 15, 2015 20:10:48 GMT
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Post by sigurdur on Feb 18, 2015 17:45:56 GMT
I hope I live at least another 5 years. At my age, ya never know. I had friends dropping like flies after the swatter a few years ago.
The next 5-10 years are going to be very interesting. Folks like Astro predict a long period of cooling. The AMO signal predicts a long period of flat to cooling temps. The Arctic is getting warmer, but really what that does is expel heat from earth at an astonishing rate. Strat is so close to surface most of the year that it is like opening a door when it is -40C.
We all know climate changes, we all know sea levels will continue to rise. That is what happens during interglacials. As long as the temperature stays within the bounds of an interglacial, I will be happy, my kids will be happy.
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Post by Ratty on Feb 19, 2015 4:15:45 GMT
Get that camper underway Sig. Travel like there's no tomorrow. **
** Apologies for the Al Gore reference.
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Post by duwayne on Feb 27, 2015 14:58:58 GMT
Climate researches continue to discover that natural variability plays a significant role in the Earth's climate system. This paper says almost exactly what I (and others) have said for many years. What isn't said is that this knowledge means that the climate models are useless because they do not include this(and other)extremely important variables. Manmade global warming over the past decade has probably been partly offset by the cooling effect of natural variability in the Earth’s climate system, a team of climate researchers have concluded.
The finding could help explain the slowdown in temperature rises this century that climate sceptics have seized on as evidence climate change has stopped, even though 14 of the 15 hottest years on record have happened since 2000.
The authors of the new paper describe the slowdown, sometimes called a global warming hiatus or pause, as a “false pause”. They warn that the natural cycles in the Pacific and Atlantic that they found are currently having an overall cooling effect on temperatures will reverse in the coming decades – at which point warming will accelerate again.
“It [the new paper] has important implications for understanding the slowdown,” said Byron A Steinman, the lead author of the study, which was published in the journal Science on Thursday.
“I think probably the biggest thing that people should understand is there is randomness in the climate system. The recent slowdown in no way invalidates the idea that continued burning of fossil fuels will increase Earth’s surface temperature and pose a substantial burdens on human society,” Steinman told the Guardian.
The slowdown in no way invalidates that the burning of fossil fuels will increase Earth’s surface temperature. Byron A Steinman, lead author of the study
The research looked at two long-term climate phenomenon that play a key role in global temperatures, the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation. The authors worked to strip out ‘external forces’ on those oscillations, such as volcanoes and the burning of fossil fuels, to work out how much they varied naturally, or internally.
Such natural variability is likely to have had a substantial influence over the span of several decades on temperatures in the northern hemisphere, they concluded, of up to 0.15C in a warming or cooling effect – and in recent years it has been a cooling one.
“We find that internal multidecadal variability in northern hemisphere temperatures, rather than having contributed to recent warming, likely offset anthropogenic warming over the past decade,” the authors write.
Michael E Mann, one of the co-authors, blogged that: “Our conclusion that natural cooling in the Pacific is a principal contributor to the recent slowdown in large-scale warming is consistent with some other recent studies, including a study I commented on previously showing that stronger-than-normal winds in the tropical Pacific during the past decade have lead to increased upwelling of cold deep water in the eastern equatorial Pacific”.
Steinman said the new work was a substantial step forward and employed state-of-the-art climate models that previous studies on the subject had not used.
But the paper warned that the natural cycles are likely to reverse in coming years, adding to manmade warming in the coming decades. “When that trend reverses, that will then add to warming, so warming will accelerate,” said Steinman. He added that it was difficult to say exactly when in the next few decades that would happen.
Mann wrote on the RealClimate blog that such an acceleration “is perhaps the most worrying implication of our study, for it implies that the ‘false pause’ may simply have been a cause for false complacency, when it comes to averting dangerous climate change”.
Ben Booth, a scientist at the Met Office who was not involved in the study, said that the new work provided a more nuanced picture of the role natural cycles play in the climate. “What this result shows is that on a decadal time scale, the variability in the oceans can have an important role to play in dampening warming,” he told the Guardian.
“The results support the conclusion that cool Pacific temperatures have played a key role in modulating atmospheric temperature increases in the past 10 years, only partially offset by modest warming in the Atlantic,” he wrote in a commentary also published in Science.From Tallbloke's website
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Post by duwayne on Mar 20, 2015 17:57:36 GMT
Sigurdur posted a link on another thread to an analysis by Nic Lewis which shows that the “Climate Sensitivities” are almost certainly significantly below the levels claimed by the IPCC. The Bishop Hill website has charts which compare the Nic Lewis calculations to the IPCC estimates (shown in gray). The equilibrium sensitivies are the increase in global temperature per doubling of atmospheric CO2 after all feedbacks have had time to occur. The transient sensitivities are before all the feedbacks are completed but include some feedback effect from prior years. Nic Lewis estimates the equilibrium sensitivity (above) to be 0.6 to 2.5 while the IPCC estimates 1.5 to 4.5. However, the comparison is actually worse than shown since the Nic Lewis estimate is for all contributors to warming, not just CO2. If CO2 was only 2/3rds of the Greenhouse Gases then the climate sensitivity for CO2 would logically be only 2/3rds of the value shown and thats what should be compared to the IPCC estimates in gray. There are 2 key conclusions in the study beyond the obvious one that the IPCC sensitivity estimates are far too high. The equilibrium sensitivities are not a lot higher than the transient sensitivities as claimed by IPCC (note the 2 charts are on different scales) and the aerosol effect on historical temperatures is much lower than the IPCC claims (which was the IPCC reason for adding a "plug factor" into the models to bring them closer to the observations. The other obvious conclusion is that the top of the IPCC range is totally senseless but of course, that’s what scares the public. If all of this is hard to follow, I’ve calculated climate sensitivities below which are nothing more than the rise in temperature per doubling of CO2 for various historical time periods using the Hadcrut4 anomalies and the RSS satellite anomalies. Then I’ve used these sensitivities to calculate the temperature increase between now and the end of the century assuming atmospheric CO2 continues to grow at the same incremental rate as it has over the last 5 years and the other contributors to warming grow at the same rate as the CO2 effect. All calculations are based on the standard presumption that the CO2 effect is logarithmic.
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Post by sigurdur on Mar 20, 2015 19:52:06 GMT
Thanks Duwayne:
I don't know much, but I do concur with what you wrote, and the findings in your chart.
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Post by sigurdur on Mar 21, 2015 19:48:21 GMT
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Post by sigurdur on Mar 21, 2015 19:52:29 GMT
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Post by graywolf on Mar 22, 2015 11:39:36 GMT
With China now appearing hell bent on cleaning up their inner city pollution the 'dimming' associated with their meteoric industrialisation appears to have 'peaked'. This appears to have coincided with the flip of the negative naturals that had slowed the rate of atmospheric temp changes over the past 15 years. We will now begin to see us enter a period of record/near record atmospheric temp years over the coming decade. By this time China's 'dimming' will have reduced further releasing much of the 2 to 3Wm currently locked out of the global temp record.
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Post by nautonnier on Mar 22, 2015 11:50:34 GMT
With China now appearing hell bent on cleaning up their inner city pollution the 'dimming' associated with their meteoric industrialisation appears to have 'peaked'. This appears to have coincided with the flip of the negative naturals that had slowed the rate of atmospheric temp changes over the past 15 years. We will now begin to see us enter a period of record/near record atmospheric temp years over the coming decade. By this time China's 'dimming' will have reduced further releasing much of the 2 to 3Wm currently locked out of the global temp record. You may be putting too much faith in 'dimming' by aerosols see this new paperThis has several effects it means that the dip in the 70's claimed to be due to dimming may have been due to 'natural processes' it also means that the models that used aerosol forcing parametrization as a wedge of cardboard to get the hindcasts right are now completely falsified. It also has the effect of considerably lowering the ECS to CO2.
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Post by duwayne on Mar 22, 2015 15:03:03 GMT
Sigurdur, I'm a big believer in the effects of ocean currents on global temperatures but I've focused my attention mainly on the 60-year ocean current oscillation because I believe it is somewhat predictable and the impacts over a 150-year period are significant and apparent.
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Post by sigurdur on Mar 22, 2015 15:10:37 GMT
Sigurdur, I'm a big believer in the effects of ocean currents on global temperatures but I've focused my attention mainly on the 60-year ocean current oscillation because I believe it is somewhat predictable and the impacts are apparent. Duwayne: I agree about the 60 +/-8 year cycle and temperature effects. One point of interest, which I just posted on the Arctic Ice page is how the Arctic ocean cold is slowly creeping south. Note the difference from 2000 to 2015. While not dramatic, it is very evident at how the area of cold is slowly enlarging.
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Post by nautonnier on Mar 29, 2015 1:28:59 GMT
Interesting article in Jo Nova about Stephen Wilde's theory on ozone and troposphere: Is the Sun driving ozone and changing the climate?The interesting part comes at the end (spoiler alert ) "Quick reminder: The delay of one sunspot cycle in the ND theory overcomes the objection that because TSI and so on peaked around 1986 and surface temperatures kept rising to about 1997, the Sun cannot be driving temperature. The delay can explain this: 1986 + 11 = 1997. The delay also means that the fall off in bulk TSI around 2004 presages a fall in surface temperatures around about one sunspot later, around 2017: 2004 + 13 = 2017. The “pause” the believers of the carbon crisis have lately admitted to may turn out to be a “plateau”Yet another support for precisely what Theo has been telling us.
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