Your question is improperly worded to reflect the reality of the current warming. There has not been a pause in the warming. There has been a slower rate of surface warming, but certainly not a pause in the global warming. Like our military, global warming covers the land, air and seas.
A negative phase has not overpowered the radiative forcing of man's carbon dioxide emissions. Should this be true then we would have seen global temperatures drop and not just slow the rate of the previous surface warming. Natural variations in the climate will mask the true effects of our adding CO2 into the atmosphere, but only for the short durations of the natural variations. As with a fire, if you added an amount of water to the fire you would hinder the fire's ability to consume fuel. You could only overcome the fire's ability to consume fuel by constantly adding water to the fire until the fire has been put out completely. The natural variations of the climate have not been sufficient to completely overcome the warming created by anthropogenic CO2 emissions. (I would love to see the scientific, peer reviewed studies that would show otherwise.) Likewise, adding a little oxygen to a fire will increase the fire's ability to consume fuel, but only for as long as the extra oxygen is being added. However, there can be an increase in the intensity of the fire, by adding more oxygen, that it can now consume fuels that were of too high of a flash point for the unaided fire to consume. A run away effect?
I will sum this up by stating that scientists, of nearly all fields of study in the sciences, have examined the natural variations within our climate and have not been able to account for the amount of global warming (land, air ad sea) due just to the natural variations. Did you not already know this??? Do you have any scientific, peer reviewed studies that can show how the natural variations in our climate would account for the observations being made in how our climate is now changing?
I find it funny the way deniers lurch from trying to ignore natural variation to trying to fit it to their fictions.
The answer to your question (which I'm sure you will ignore) is that, if you are talking about the PDO which is a longer term effect than ENSO, there is data on it going back to 1900
http://en.wikipedia.org/wiki/File:PDO.sv...
It has moved either side of a mean in that time and you can see this in the temperature data.
Particularly the event from the 40's to the 70's. if there were just ENSO then you would have an oscillating temperature not one that has climbed pretty solidly since 1900.
http://climate.nasa.gov/key_indicators#g...
The major hole in your theory is that before the 40's cool ENSO there was a strong positive ENSO and temps did rise but they continued to rise and even during the intense negative ENSO of the 40's temps stayed above what they had been through much of the previous negative phase.
Today temps are well above what they where during the positive ENSO of ~1925-43 in spite of the fact we have been in a negative ENSO since 2005. I have stated this many many many times and deniers replies switch from insult to trying to correct my grammar to ranting about whatever, but clearly as can be seen from jim et al, they have no real answers, but then I get the feeling you are no looking for real answers.
In your own words
"then if a negative phase of natural variation can overpower the radiative forcing of man's carbon dioxide emissions for the past 15 years (1997-2013)"
You seem to be playing the same old denier tale of 15 year of cooling which simply doesn't exist, it is based purely on using the single very warm year of 1998 as a starting point, a year that was indeed pushed much higher than the effect of AGW by the strongest ENSO of the last 100 years.
A fact easily seen in the above NASA temp data, this denier myth also try's it's best to completely ignore the years 2005 & 2010 which were warmer or the host of other years through the 2000's that where very close to 1998 (without the aid of such an ENSO) if that 98' ENSO had been more in line with the usual positive event then many of the years of the 2000's would have been easily warmer than 98' of course the other thing deniers try very hard to ignore here is the simple fact that as a decade the 2000's is the warmest decade in the modern record, in spite of 98'.
Deniers also, while trying to play up cooler years like 2008 or 2011, ignore the fact that these years are still warmer than years like 1995, which at the time was the warmest year in the modern record.
ANTARCTICICE
We have not been in a negative ENSO state since 2005, There have been 3 substantial El-Nino events since 2005 that are the only reason global temperatures have not declined more over the last decade, perhaps you mean PDO?
http://www.esrl.noaa.gov/psd/enso/mei/ts...
JeffM:
The amplitude of a multivariate index like the ENSO multivariate Index must be carefully compared when ranking its effectiveness relative to other El-Ninos, at warming the globe. The Sea Surface temperature anomalies of the last 3 ENSO events caused significant warming, but the strongest El-Nino ever recorded was completely canceled out by El-Chichon.
The problem with "natural variation" is that its effects do not seem to be predictable. In fact, it is poorly understood. So much so that if anything unexpected happens we can blame it on natural variation and everyone is happy.
If the science is settled and the models accurate shouldn't natural variation be predictable and all accounted for? It must have causes.
Although our current models might not work only with "natural variations" and without man-made influences that only indicates a failure of the models. The climate can make larger swings without any help from man at all - and it has been doing it, unaided, for billions of years!
Our oceans hold a lot more heat than our atmosphere, and afaik ocean temperatures have been showing a more or less *steady* rise over the past 5 or so decades. There have been minor ups and downs, but far less than in the surface temperature record.
http://www.epa.gov/climatechange/science...
Also, if you look at running 5-year means or the like, you'll see much the same. The averaging over a slightly longer time period also cancels out a lot of the "noise", and shows... a fairly steady increase in temperatures.
If it was all "natural cycles" and whatnot, then unless there is a natural cycle that is *trending* in the right direction, I'd expect the long-term averages--30+ years--to be basically flat. They aren't, they're trending upwards.
Dr Akasofu has built a model based on this idea. That there is a natural warming and cooling cycle, being added to a linear trend of a multidecadal cycle. This predicts temperatures will be much the same for the next 30 years.
That is a very good question. I suspect that is why alarmists have towed the line that aerosols caused the cooling around 1970s but when they came riding in on their white horses and reduced sulfur emissions, GW resumed. It is also why they always manipulate the previous climate records to smooth out previous variation. Natural variation is their enemy and they know it. Of course they claim it is only done as new information is obtained and they are "corrected". It certainly seems that CO2 isn't driving the climate warmer lately. I know you haven't, nor have I suggested that CO2 doesn't do anything. The real question is, does it do enough to warrant massive government intrusion in the energy sector and making everything vastly more expensive.
Edit: I guess Antarcticice is leaving out the 1930s with his convenient "recent" claim when he claims 1995 was the warmest in "recent" history. Obviously if he just said history, his argument would have fallen on its face. Who knows? With these science illiterates, it is hard to say what they are thinking because it is more about believing than thinking.
I'll put it this way; why shouldn't we expect the rate of warming to vary because of natural variation?
There would have to ba a positive natural variation to do that.
http://www.woodfortrees.org/plot/sidc-ss...
And what will we find? The two scientists out of 77 who say that humans are not causing global warming. A scientist who is in the pay of the oil industry has no incentive to explain the supposed "pause." But I find it hard to believe that if an amature like myself knows about the Asian Brown Cloud and the yellow ball in the sky, certainly experts know about these things.
edit
15 years of statistically insignificant warming =/= 15 years of no warming.
http://www.woodfortrees.org/plot/sidc-ss...
Tomcat: Those are not 'substantial El-nino events'. The only one of those that can be classified as 'substantial' is that of 2009 and yet it barely makes that category.
http://www.esrl.noaa.gov/psd/enso/mei/el...
... then if a negative phase of natural variation can overpower the radiative forcing of man's carbon dioxide emissions for the past 15 years (1997-2013), why can’t a positive variation have added to it for 20 years (1977-1997) previous to that?
Obviously natural variation is stronger than CO2 warming and the only conclusion we can come to, is that climate sensitivity to CO2 is much lower than expected.
I'd say have a mantra stamp as a standard contributory value. That way local and national governments are recession proof. The price of emission wouldn't matter it becomes folded into usage.
You think I'm kidding, but I'm not. It's coming your way.
Are you attempting to make alarmist's brains explode?
