Question:
Can natural variability explain warming as well as the pause?
Ian
2014-01-31 21:30:44 UTC
As everyone knows, there has been about a 17 year pause in Global Warming. Several alarmists can tell you that there definitely is no pause occurring and also that the pause is occurring because of natural variability (or those damn Chinese fireworks). One of their theories about why the pause is occurring is that there is missing heat hiding in the deep ocean where unfortunately, awwwww, we can't really measure it.

If natural variability can mask Global Warming, can it also be used to explain any supposed warming?

http://wattsupwiththat.com/2014/01/31/open-letter-to-kevin-trenberth-ncar/#more-102471
Eleven answers:
?
2014-02-01 16:23:05 UTC
Yes it could. The time scales are similar, and the amount of warming is small, at .7C.

Now, note that natural variability one would expect to be on a neutral effect over one cycle, but here we have warming and a pause, which suggests an overall positive trend. Of course that could also be part of a natural warming that has been happening for centuries.



Somehow C denies a pause because there are the warmest temperatures we have ever had. C consider what you would say if we had the exact same temperature every year until 2200.

'How can you denier dodos think there is a pause when the 204 warmest years have all been within the last 205 years How ridiculous can you get?? '



It is possible for global warming's effect to be small and hidden within natural variation.
pegminer
2014-02-01 15:40:05 UTC
No, it can't--at least not at the same level of probability. Forgetting about the actual physics of the problem for the moment, the signal of global warming taken over multidecadal time scales is much greater than the noise. That's why you look over long time periods rather than short ones. It's a matter of probability: the noise can easily swamp the signal over a year time period, it's significantly less probable over a decade, and even less probable still over many decades.



This effect of a "pause" is not particularly difficult to simulate if you have access to software such as Matlab, or perhaps Excel. Just plot an upward trend with random noise added to it where the noise has the characteristics of the year-to-year variability seen in the data sets. The trend will still be upwards, but occasionally you'll have time periods where it looks like the temperature is going staying the same, or even going down.
Jeff M
2014-02-01 21:33:15 UTC
Ian: I find your response to Trevor amusing. Especially considering that is how satellites, the ones you are basing your '17 years pause in global warming' statement on, measure the temperature.



http://www.drroyspencer.com/2010/01/how-the-uah-global-temperatures-are-produced/



I, too, would be interested in knowing what natural cycles you are claiming is the cause. Just remember that your claim has to meet all the data that has been recorded including those measurements of spectral frequencies and measurements of cyclic phenomena.
Rio
2014-02-01 12:53:06 UTC
Yes but then that's takes you back too the age old question of how much and for how long.



NASA shows the following graphic, where you can see that the warmer years tend to be those with an El Niño in the tropical Pacific (red years), while the particularly cool years are those with La Niña (blue years). Figure 2 The GISS data, with El Niño and La Niña conditions highlighted. Neutral years like 2013 - See more at: http://www.realclimate.org/index.php/archives/2014/01/global-temperature-2013/#sthash.j9ziEejY.dpuf
?
2014-02-01 09:52:18 UTC
Firstly, the measurements you cite as being indicative of a 'pause' are based on surface temperature measurements. The surface of our planet is, as you suggest, a thin layer. Therefore those measurements do not account for what happens in the atmosphere above the surface or in the ocean depths. Basing a conclusion on those results is sort of like declaring the heating in my apartment isn't working by measuring the temperature with a thermometer glued to a window.



Secondly, we have huge amounts of evidence that the oceans are warming. A good example is:



http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/



which, if you click through the links, shows temperature measurements down to 2 km in depth in the ocean. The data is based on nine million temperature profiles from all the world's oceans. So, frankly, arguing that we can't measure the temperature of the ocean is flat out wrong.



Thirdly, what the 'pause' shows is that temperature readings at the surface haven't changed much over a period of 10, 12, 15, or 17 years depending on who is claiming the pause. As you say, this is because of 'natural variability' (more on that in a minute). What that means is that your data is noisy. And to establish a trend in noisy data you need to continue taking the data until the magnitude difference between the start and end of your measurements due to the trend is greater than the noise. This isn't some mad conspiracy to slap down skeptic arguments, but mathematical and experimental reality. In other words, we need to keep taking data to see what happens and drawing a conclusion now is stupid.



Fourthly, the data may indicate a 'pause' in this set of results over that period of time. When you compare the last 17 years with the 17 before it, and the 17 before that, there is definite upward trend in global surface temperature. This is because, when you do that, you can separate the trend from the noise.



Fifthly, 'natural variations' is a bad comment by anyone, warmist or denier. Natural variations have a cause and are not just random events that we can roll out to explain away data.



Sixthly (is that a word?) our satellite systems are still telling us there is a growing imbalance between energy going into the earth and energy coming back. Energy is still being trapped and since the laws of physics tell us that energy can't go missing, that means it must be driving some process on earth that isn't the surface temperature. Harping on about 'the pause' doesn't explain where that energy has gone. It simply states what you see in a graph rather than actually constructing a scientific argument.



Finally, skeptics like to pull one dataset out and hold it up as 'proof' that something is wrong with AGW. Unfortunately they then ignore the other datasets. You know, things like O2 and CO2 concentrations in the atmosphere, isotope ratios of carbon in the atmosphere and plants, rising sea levels, etc. So while the 'pause' might suit your argument, you can't explain any of the other observations on the basis of the pause or why that pause has happened. If, for example, you argue that 'the pause' is due to reduced solar activity and that the CO2 rise is mostly due to oceans, then how can CO2 continue to rise while the sun has reduced? It's this lack of connected thinking, this focusing on a single set of measurements, this cherry-picking of bits that conform to your belief and ignoring bits that don't that is the reason we leave the analysis and conduction of science to trained professional scientists.
?
2014-02-01 05:37:56 UTC
How can you denier dodos think there is a pause when the 17 waemest years have all been within the last 18 tears How ridiculous can you get??



WUWT isn't a credible source



ian...You have used this same lame link before. I can only guess Christopher Monckton is your hero. You both have a lot to learn about AGW and the reality of continued warming. I actually thought you were intelligent at one point, sorry I was so wrong about you.



Plus you know you have hit an ignorance denier nerve when they all attack you simultaneously
Trevor
2014-02-01 10:21:08 UTC
No, natural variability can not explain the warming.



We can precisely measure the amount of energy entering and exiting Earth’s atmosphere, this has varied by less than a thousandth from the mean and could only ever cause warming or cooling on very long time scales, several hundreds of years. We can eliminate all factors beyond Earth’s atmosphere.



If there is a natural explanation to be found then it has to be here on Earth, and there isn’t one. We have identified the major natural variations, and although we often don’t fully understand the mechanisms behind them, we have enough observational data to identify their effects.



During the periods of observed warming there were no natural cycles or variations that came anywhere close to explaining the amount of warming. In fact, some of the most pronounced warming occurred when the natural variations were causing cooling.



For many sceptics the idea that warming was caused by natural variations was perhaps the easiest of all cop-outs, it was an excuse they used for years although not once did they actually suggest what variation or cycle could be causing the warming. And bear in mind, that this magical cycle would have needed to be greater than the sum total of all other cycles combined, so it’s not something that could easily be overlooked.



The current pause in warming does actually tie in perfectly with the negative phase of the Pacific Decadal Oscillation. So precise is the correlation that even amongst the noise of other variations you can look at a temperature graph and identify to the month when the PDO switched to negative, namely September 1998.



Not only that, but the PDO Index since then has dropped to it’s lowest known level meaning a very strong cooling influence. If there was no global warming then temps in the last 17 years wouldn’t have been static, there would have been a very marked cooling.



Despite the precise correlation, from a scientific perspective this isn’t proof of anything (‘proof’ in science requires a 5 sigma confidence level or a 99.99994% probability, many magnitudes greater than that which a sceptic considers to be proof).



For now, the correct approach is to say that factors such as the PDO, greater heat transference to the oceans, reduced sunspot number and the emissions of dimming components are the likely causes of the pause in warming. It’s probable that the PDO alone is responsible for the sizeable majority of the cooling influence.



Concerning oceanic observations, we actually have just over 20,000 ocean sensors relaying a vast amount of data. The ARGO network has thousands of deep water sensors that take a profile of the oceans from sea-surface to a depth of 2,000 metres before regularly surfacing and transmitting their data via satellite. The network covers the oceans on a global scale and has provided billions of datapoints from which we can accurately determine the amount of heat present in the upper 2,000 metres of the oceans.



It’s more bad news for the sceptics I’m afraid. Right at the time when the atmospheric warming stopped, oceanic warming increased significantly. Since 1998 the oceans have absorbed about 160 zettajoules of energy, that’s the same amount that would have been in the atmosphere had the warming trend prior to 1998 continued. To put it into context, in the 15 years prior to 1998 the oceans absorbed about 45 zettajoules. Further, the rate at which heat is entering the oceans is increasing and in the last couple of years it’s been about 25 zettajoules per year.



Again, despite the fact that this might appear to be absolute proof of where the ‘missing heat’ has gone, it’s still not enough for science to declare a definitive conclusion.



Given your scepticism, I would be interested to hear which cycle(s) or natural variation you think caused or contributed to the warming episodes that have brought temperatures to where they are today.



- - - - - - - -



EDIT: RE YOUR ADDED DETAILS



You don’t like the FACT that we can measure the flow of energy into and out of Earth’s atmosphere so you dismiss it by claiming it’s “Bull ****. It's an estimate with a lot of uncertainty.”



Do you have anything to back up your claim. No you don’t. If you don’t think we can calculate such things then you’re only kidding yourself. Such statements only serve to demonstrate just how little you know about climates.



Total solar irradiation can be calculated to an accuracy of 99.971%, or ±0.4W/m² from the mean TSI of 1363W/m².



Perhaps you’d care to explain how the maximum uncertainty of 0.4W/m² could account for observed warming/cooling. It’s actually very easy, if you know the first thing about climates you’ll do it in a matter of seconds. I won’t hold my breath.
?
2014-02-01 08:06:02 UTC
Look at C. Ha! Ha! Ha! This has been explained over a hundred times and yet C can't get it. It is Goebbels' old reliable means of dumbing people. Repeat the lie and ignore the truth.



Keep it up C, it only shows your ignorance.



In direct answer to the question. Yup!



WUWT isn't a credible source? Yet GISS and NASA are?



http://www.c3headlines.com/fabricating-fake-temperatures.html



Ha! Ha! Someone has a screw loose.
Pindar
2014-02-01 07:15:08 UTC
Warmers are a very anti science bunch, even when their own pro warming organisations such as East Anglia University and the Met office grudgingly state no warming for 15 years, they still chant it's warming, it's warming. They are the true deniers of both reality and their own high priests.
Kano
2014-02-01 08:29:26 UTC
Can we ask C if he understands the difference between warming and warm, perhaps he should look in a dictionary
?
2014-02-01 06:55:29 UTC
Exactly, C.


This content was originally posted on Y! Answers, a Q&A website that shut down in 2021.
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