From ETH Zurich –Why global warming is taking a break
The average temperature on Earth has barely risen over the past 16 years. ETH researchers have now found out why. And they believe that global warming is likely to continue again soon.
Global warming is currently taking a break: whereas global temperatures rose drastically into the late 1990s, the global average temperature has risen only slightly since 1998 – surprising, considering scientific climate models predicted considerable warming due to rising greenhouse gas emissions.
Climate sceptics used this apparent contradiction to question climate change per se – or at least the harm potential caused by greenhouse gases – as well as the validity of the climate models. Meanwhile, the majority of climate researchers continued to emphasise that the short-term ‘warming hiatus’ could largely be explained on the basis of current scientific understanding and did not contradict longer term warming.
Researchers have been looking into the possible causes of the warming hiatus over the past few years. For the first time, Reto Knutti, Professor of Climate Physics at ETH Zurich, has systematically examined all current hypotheses together with a colleague. In a study published in the latest issue of the journal Nature Geoscience, the researchers conclude that two important factors are equally responsible for the hiatus.
El Niño warmed the Earth
One of the important reasons is natural climate fluctuations, of which the weather phenomena El Niño and La Niña in the Pacific are the most important and well known. “1998 was a strong El Niño year, which is why it was so warm that year,” says Knutti. In contrast, the counter-phenomenon La Niña has made the past few years cooler than they would otherwise have been.
Although climate models generally take such fluctuations into account, it is impossible to predict the year in which these phenomena will emerge, says the climate physicist. To clarify, he uses the stock market as an analogy: “When pension funds invest the pension capital in shares, they expect to generate a profit in the long term.” At the same time, they are aware that their investments are exposed to price fluctuations and that performance can also be negative in the short term. However, what finance specialists and climate scientists and their models are not able to predict is when exactly a short-term economic downturn or a La Niña year will occur.
Longer solar cycles
According to the study, the second important reason for the warming hiatus is that solar irradiance has been weaker than predicted in the past few years. This is because the identified fluctuations in the intensity of solar irradiance are unusual at present: whereas the so-called sunspot cycles each lasted eleven years in the past, for unknown reasons the last period of weak solar irradiance lasted 13 years. Furthermore, several volcanic eruptions, such as Eyjafjallajökull in Iceland in 2010, have increased the concentration of floating particles (aerosol) in the atmosphere, which has further weakened the solar irradiance arriving at the Earth’s surface.
The scientists drew their conclusions from corrective calculations of climate models. In all climate simulations, they looked for periods in which the El Niño/La Niña patterns corresponded to the measured data from the years 1997 to 2012. With a combination of over 20 periods found, they were able to arrive at a realistic estimate of the influence of El Niño and La Niña. They also retroactively applied in the model calculations the actual measured values for solar activity and aerosol concentration in the Earth’s atmosphere. Model calculations corrected in this way match the measured temperature data much more closely.
Incomplete measured data
The discrepancy between the climate models and measured data over the past 16 years cannot solely be attributed to the fact that these models predict too much warming, says Knutti. The interpretation of the official measured data should also be critically scrutinised. According to Knutti, measured data is likely to be too low, since the global average temperature is only estimated using values obtained from weather stations on the ground, and these do not exist everywhere on Earth. From satellite data, for example, scientists know that the Arctic region in particular has become warmer over the past years, but because there are no weather stations in that area, there are measurements that show strong upward fluctuations. As a result, the specified average temperature is too low.
Last year, British and Canadian researchers proposed an alternative temperature curve with higher values, in which they incorporated estimated temperatures from satellite data for regions with no weather stations. If the model data is corrected downwards, as suggested by the ETH researchers, and the measurement data is corrected upwards, as suggested by the British and Canadian researchers, then the model and actual observations are very similar.
Warming to recommence
Despite the warming hiatus, Knutti is convinced there is no reason to doubt either the existing calculations for the climate activity of greenhouse gases or the latest climate models. “Short-term climate fluctuations can easily be explained. They do not alter the fact that the climate will become considerably warmer in the long term as a result of greenhouse gas emissions,” says Knutti. He believes that global warming will recommence as soon as solar activity, aerosol concentrations in the atmosphere and weather phenomena such as El Niño naturally start returning to the values of previous decades.
Literature reference
Huber M, Knutti R: Natural variability, radiative forcing and climate response in the recent hiatus reconciled. Nature Geoscience, online publication 17 August 2014, doi: 10.1038/ngeo2228
I am sure there are plenty of airport and inner city car parking lots that have been overlooked in the quest for higher temperatures!
I don’t think this is a new ‘explanation’ but just another variation on the “it’s just a remarkable coincidence it hasn’t warmed” explanation.
Climate change factors
MY FOUR FACTORS
1. The initial state of the global climate.
a. how close or far away is the global climate to glacial conditions if in inter- glacial, or how close is the earth to inter- glacial conditions if in a glacial condition.
b. climate was closer to the threshold level between glacial and inter- glacial 20,000 -10,000 years ago. This is why I think the climate was more unstable then. Example solar variability and all items would be able to pull the climate EASIER from one regime to another when the state of the climate was closer to the inter glacial/glacial dividing line, or threshold.
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2. Solar variability and the associated primary and secondary effects. Lag times, degree of magnitude change and duration of those changes must be taken into account. I have come up with criteria . I will pass it along, why not in my next email.
a. solar irradiance changes- linked to ocean heat content.
b. cosmic ray changes- linked to clouds.
c. volcanic activity- correlated to stratospheric warming changing which will impact the atmospheric circulation.
d. UV light changes -correlated to ozone which then can be linked to atmospheric circulation changes.
e. atmospheric changes – linked to ocean current changes including ENSO, and thermohaline circulation.
f. atmospheric changes -linked also to albedo changes due to snow cover, cloud cover , and precipitation changes.
g. thickness of thermosphere – which is linked to other levels of the atmosphere.
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3. Strength of the magnetic field of the earth. This can enhance or moderate changes associated with solar variability.
a. weaker magnetic field can enhance cosmic rays and also cause them to be concentrated in lower latitudes where there is more moisture to work with to be more effective in cloud formation if magnetic poles wander south due to magnetic excursions in a weakening magnetic field overall.
4. Milankovitch Cycles. Where the earth is at in relation to these cycles as far as how elliptic or not the orbit is, the tilt of the axis and precession.
a. less elliptic, less tilt, earth furthest from sun during N.H. summer — favor cooling.
I feel what I have outlined for the most part is not being taken as a serious possible solution as to why the climate changes. Rather climate change is often trying to be tied with terrestrial changes and worse yet only ONE ITEM , such as CO2 or ENSO which is absurdity.
Over time not one of these one item explanations stand up, they can not explain all of the various climatic changes to all the different degrees of magnitude and duration of time each one different from the previous one. Each one UNIQUE.
Examples would be the sudden start/end of the Oldest, Older and Younger Dryas dramatic climate shifts, the 8200 year ago cold period, and even the sudden start of the Little Ice Age following the Medieval Warm Period.
He could be right that it will soon start warming again. I don’t really care.
I was never angry because the world isn’t going to end on schedule. I’m angry because they keep on LYING. They lie about what they know. They lie about what they don’t know. They lie about how certain they are. They lie about the scientific value of computer models. They pick on certain natural phenomena and lie about their signifigance.
The whole business was originally a theory designed to explain events that hadn’t actually happened yet. Now a totally different set of events have happened, and they are claiming that proves the theory.
An honest man might say, “Something is happening, but it is not what we predicted.” They are not honest men.
The world could burn up, and then they would have won. They would have won, but they can never be RIGHT. Because they have lied.
The real travesty lies in the lack of accountability by those in the field. There are no standards for reconciling observations with theory as should be required by the “authentic” scientific method.
They have redefined the scientific method so that it allows them to justify their theory, instead of adjusting the theory as would be required following an “authentic” version of the scientific method.
http://en.wikipedia.org/wiki/Scientific_method
In essence, they use new theories to justify not changing the old theory. The more time that goes by with the old theory not verifying, the more new theories are conjured up.
The new theories all sound plausible……….to those sold on the old theory, with minds unable to escape their view that “the science is settled”.
Even worse, the world was informed that the science was settled some years ago and since then, the people in the world have been spoon fed propaganda that proves it.
Think of the embarrassment to those providing the proof all this time. The ruined reputations/damaged careers, if the science had not really been settled all this time.
The scientific method has morphed into something that allows for interpretation of facts to prevent that from ever happening.
Are we seeing a trend here where a plethora of “scientific” explanations emerge when one strongly held philosophy is severely questioned? As well as the pause – (halt, arrest, stoppage, termination, standstill, freeze or whatever you like to call it) of global warming the same phenomenon appears as to Why is Antarctic Sea Ice increasing?
Skeptical Science for example say it is certainly NOT because it is cooling around Antarctica. Oh no – that could never be, could it? That little possibility has been “re-analysed” and dispensed with. In fact SS allege there has been an increase of surface air temperatures around Antarctica and that even the Southern Ocean has shown strong warming over the same period that sea ice has been increasing. Mmmmnn?
But if everything is warming, you may ask, why is there more sea ice? Well, SS claims this is a result of a combination of complex phenomena including cyclonic winds around the continent and changes in ocean circulation. Satisfied?
But just in case you are not convinced there are also other contributing factors. One is the drop in ozone levels over Antarctica. The hole in the ozone layer above the South Pole has caused cooling in the stratosphere. A side-effect of this is a strengthening of the cyclonic winds that circle the Antarctic continent. The wind pushes sea ice around, creating areas of open water known as polynyas. More polynyas leads to increased sea ice production.
But wait there is more. The Southern Ocean consists of a layer of cold water near the surface and a layer of warmer water below. Water from the warmer layer rises up to the surface, melting sea ice. However, as air temperatures warm, the amount of rain and snowfall also increases. This freshens the surface waters, leading to a surface layer less dense than the saltier warmer water below. The layers become more stratified and mix less. Less heat is transported upwards from the deeper, warmer layer. Hence less sea ice is melted. Well did you ever – full marks for that one.
The Guardian aka warming aficionado Graham Readfearn also says the answer is blowing in the wind. You see what has happened, Graham informs us, is that is that greenhouse gases have caused stronger westerly winds which in turn have stirred up the waters creating ridges and rifts that help sea ice thicken.
A little paradoxical Graham admits but don’t worry all scientists understand exactly what’s going on he assures us – and the paradoxes don’t stop here. A big contributor to the increasing sea ice could be the melting of the massive Antarctic ice sheet in the west of the continent. All this added fresh water running into the ocean creates ideal conditions for Antarctic sea ice to form. (But note that this is only a could)
But don’t worry this won’t last for long. Graham re-assures us that the melting and break-up of glaciers, the changes in snowfall and changes in the air temperatures will all play a role in ensuring that the increase in Antarctic sea ice will be short lived.
Well Graham all I can say is that I hope Tim Flannery does not agree with you.
The New York University in the Science Daily reveals – pause – drumroll – that the answer lies in the Atlantic Ocean. And it is not an increase of sea ice, it is simply a re-distribution.
David tells us that “in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not diminished. Rather, it has redistributed itself in ways that have perplexed scientists, with declines in some areas and increases in others. From this study, we are learning just how Antarctic sea-ice redistributes itself, and also finding that the underlying mechanisms controlling Antarctic sea ice are completely distinct from those in the Arctic.”
Oh, that is so much of a relief David. Professor Chris Turney will be pleased if your state-of-the-art super dooper computer models can advise him of the best route through the redistributed ice next time he trips off down to the white continent. It could avoid heaps of embarrassment.
Walt Meier in the Conversation explains that fast increasing Antarctic sea ice has in part a more straightforward explanation – the data is wrong. You see it is all tied up with the Bootstrap algorithm.
I guess we can’t just estimate sea ice with an abacus and an aerial photograph. We have to rely on satellites and a mathematical step by step process or algorithm that converts raw satellite data into sea ice. Walt states that the Bootstrap algorithm (not believed to be associated with starting and self sustaining computer “bootstrapping”) was changed over time as well as different algorithms being used.
In forming the report for IPCC AR5 in 2013 two different version of Bootstrap were used. It became evident that the sea ice trend showed what looked like a step jump which was subsequently put down to data interpretation. However our diligent scientists are confident that the discrepancy is associated with a sensor calibration change in 1991 and only applied to Bootstrap Version 1.
So the good news for sceptics is that Bootstrap Version 2 is hunky dory and Antarctic sea ice extent is still increasing at a statistically significant rate. But Walt Meier now believes that “contrary to what was previously thought, the increase in Antarctic sea ice hasn’t accelerated in the past 15 years, but has been remained consistently positive at moderate levels.”
Phew! What a relief Walt, for a moment I thought that you were going to move all of the goal posts for us there. I guess “consistently positive” is still a teeny weeny bit of a worry for the warmist fraternity though?
There are lots of other comments and sub theories on why Antarctic sea ice is increasing including the Coriolis Affect and many many reassurances for the demonisers of CO2 that there is no reason to change their mind and anyway the increase in Antarctic sea ice is only slight.
But does any-one question these theories? Well at least one distinguished scientist does.
Professor Judith Curry, head of climate science at the Georgia Institute of Technology in Atlanta, says the arguments are not convincing. Judith says: “We do not have a quantitative, predictive understanding of the rise in Antarctic sea ice extent. It is becoming increasingly apparent that long-term cycles in ocean temperatures were responsible for a significant proportion of the ice decline in the Arctic – a process that may be starting to reverse.”
She also revealed that because of the ‘pause’, in which world average temperatures have not risen for more than 16 years, the Arctic ice decline has been ‘touted’ by many as the most important evidence for continued global warming.
But in her view, climate scientists have to consider evidence from both Poles. She added: “Convincing arguments regarding the causes of sea-ice variations require understanding and ability to model both the Arctic and Antarctic.”
Or to put it more succinctly Judith? – there is absolutely no question about the cause of observed Arctic sea ice decline but for Antarctic sea ice increase – How do I love thee? Let me count the ways.
This has to be some revenge of the nitwits.
He said the discrepancy cannot be solely attributed to the models predicting too much warming.
Why not?
He doesn’t bother mentioning a single word as to how he reached that conclusion.
What is his reason for starting his study from that presumption?
It is certainly a possibility that the models are entirely at fault.
Especially since the warming which the AGW models are really addressing is the 20 year period from free 70s to the 90s with 30 years of cooling previously and now nearly 20 years of cooling after.
In short the models suck.
Hold the presses — did I just see a warmist study say in effect “It’s the sun, stupid” ?
Let’s look at the data: TSI Reconstructions, courtesy of Leif Svalgaard.
Since the “pause” is within the “Actual Observations” window, we will ignore the historical reconstructions. I do not see any sign of significantly weaker TSI in the past few years. The peak-to-trough difference in most cycles appears to be 1 Watt per square meter at most, with some cycles less than that. The maximum peak appears to be in 1980 at about 1361.7 w/m^2; the most recent peak in 2014 appears to be about 1361.3 for a difference of 0.4 w/m^2. The corresponding minima are 1360.6 and 1360.3. To all figures add error bars of about +/- 0.1 because I am just eyeballing the chart and I need new glasses. So TSI maximum has declined about 0.4 w/m^2 relative the the largest peak actually observed and TSI minimum has declined about 0.3 w/m^w relative to the same cycle.
In roughly the same period (1980 – 2013) the IPCC claims the forcing due solely to CO2 increased from 1.058 to 1.884 w/m^2, for an increase of 0.826, or over double the decrease in peak TSI over the same period. See here for the table. Note this forcing increase is just for CO2; increases in methane, nitrous oxide, and several CFCs add another .329 w/m^2 of forcing.
So the IPCC (AR4) says total greenhouse gasses in CO2 equivalence went from 386 PPM in 1980 to 478 PPM in 2013 for a total forcing increase of 1.155 w/m^2. And yet a decrease in TSI of at most 0.4 w/m^2 (plus or minus eyeball error factor) is supposed to explain the pause?
Either I or the peer reviewers are missing something.
“Our models are not wrong…….”
“ITS THE OBSERVED DATA that is wrong…..”
Stupidity should be painful… Sometimes you cant bet on the next line of stupidity these people will use as an excuse.
Alan Watt, Climate Denialist Level 7 says:
August 19, 2014 at 5:51 pm
….
Either I or the peer reviewers are missing something.
===============================================
Alan,
As you have so eloquently shown, it is the original paper which is mathematically challenged and as for the peer reviewers. Lets just say, they are all pals! They would have to be to allow something this grossly in error to get beyond them. Proof positive that this paper is propaganda for the faithful.
Nicely done sir!
Knutti believes: “global warming will recommence as soon as solar activity, aerosol concentrations in the atmosphere and weather phenomena such as El Niño naturally start returning to the values of previous decades”.
Since he claims to understand it all, then here is the simple question he should be able to answer: WHEN?
Do you know a way to increase the temperature of the Earth without also increasing the rate energy radiated from Earth to space?
There are enough errors in the article to invalidate the entire paper. First, professor Knutti knows nothing about the El Nino and the La Nina. That 1998 super El Nino does not belong to the group of El Ninos that are part of the ENSO oscillation. It is an exception that happens once in a century and involves much more warm water than that circulating in the ENSO system. There are only two possible outside sources for this extra warm water: the Indian Ocean or the Southern warm pool. Despite its importance to our climate none of the billions assigned for climate research was ever used to study its origin and most people don’t even know it exists. Money went to prove greenhouse warming for which they still don’t have the proof. The ENSO system itself involves first building up the Indo-Pacific Warm Pool by trade winds, followed by back flow of an El Nino wave via the Equatorial counter-current. It is an east-west oscillation with a natural period of about five years. When it gets to South America it runs ashore, spreads out north and south along the coast, and warms the air above it. Warm air rises, interferes with trade winds, joins the westerlies, and we notice that an El Nino has arrived. But any wave that runs ashore must also retreat. As the El Nino wave retreats water level behind it drops half a meter, cold water from below wells up to fill the vacuum, and a La Nina has started. As much as the El Nino warmed the air, La Nina will now cool it and the global mean temperature stays unchanged. This is why the ENSO oscillation has nothing to do with global warming. There are five El Nino peaks in the eighties and nineties that demonstrate the constancy of this global temperature. You can see this clearly in the satellite display shown in Figure 15 of my book “What Warming?” Unfortunately all ground-based temperature curves show a fake warming in this time slot. It is one glaring example of falsified global temperature, manufactured to prove a warming that does not exist. I personally regard it criminal. The only real warming in the nineties started in 1999, raised global temperature by a third of a degree in only three years, and then stopped. I attribute it to the warm water brought over by the super El Nino, not to any imaginary greenhouse warming. There has been no warming since then as the well-known pause/hiatus tells us. Hansen took advantage of this step warming and pointed out that nine out of ten warmest years happened to be in the decade between 2000 to 2010. Of course he neglected to mention that there was no warming during that entire decade and chalked it all up to his personal greenhouse effect.
We can ignore all the talk about solar cycles because no connection has been demonstrated. We can also ignore his talk of cooling by volcanoes because I have demonstrated that volcanic cooling does not exist (pp. 17-21 in my book). As for climate models, they are no good whatsoever and the whole operation should be closed down. And that “incomplete” data? I suggest they keep their hands off any data, forget about inventing data where none exists, and start looking for the source of this fake warming.
I already mentioned how “He said the discrepancy cannot be solely attributed to the models predicting too much warming.”
Not only can it, it’s the only rational thing to presume is the problem
He should have started with that. Not excluding the possibility.
His other bias reveal is this,
….”whereas global temperatures rose drastically into the late 1990s, ”
“drastically”?
Adv. 1. drastically – in a drastic manner
dras·tic (drstk)
adj.
1. Severe or radical in nature; extreme: the drastic measure of amputating the entire leg; drastic social change brought about by the French Revolution.
2. Taking effect violently or rapidly: a drastic emetic.
His absurd use of “drastically” assures us his research is crap.
“If the model data is corrected downwards, as suggested by the ETH researchers, and the measurement data is corrected upwards, as suggested by the British and Canadian researchers, then the model and actual observations are very similar.”
A tissue a tissue we all fall down.
So if we correct the model to observations if matches observations, provided we also adjust the observations.
It takes a PHD to figure that out? I wish I could do that to my stock portfolio.
“…the weather phenomena El Niño and La Niña in the Pacific…”
Since when did El Nino and La Nina become weather phenomena? I think the writer doesn’t understand something here… I’m sure it’s the first time. El Nino is a component of ENSO, which is very much a Climate phenomena, not Weather phenomena. This is why Tisdale is always beating on the Climate Models. If you can’t model ENSO accurately you can’t model long-term climate. Period.
Ah, yes the true believers. How do you say “Grasping for straws in German”
They’ve spent the last 20 years telling me the sun doesn’t matter. Now without a shred evidence it apparently does. Well if it works for CO2 it’ll work for the sun.
Apparently the temp data from the early 20th century was in dire need if cooling so why not warm up that data for the last 17 years.
I’ll bring the gin and marshmallows.
Sorry for the typos, lol.
I was all riled up!
I wish global warming would start now to cold in sydney
“A more positive surface temperature trend than reported here, of course, would make the disagreement with the models even more significant,” concludes John R. Christy et al in the 2010 paper What Do Observational Datasets Say about Modeled Tropospheric Temperature Trends since 1979?
In the sun has already occurred to change the polarity. Whether now the time for cooling of the northern hemisphere?
http://www.solen.info/solar/polarfields/polar.html
vukcevic says:
Its implications can be viewed in the light of the NASA’s Themis satellite discovery, as contained in the key statement:
”For reasons not fully understood, CMEs in even-numbered solar cycles (like 24) tend to hit Earth with a leading edge that is magnetized north. Such a CME should open a breach and load the magnetosphere with plasma just before the storm gets underway..”
http://tallbloke.wordpress.com/2014/08/19/2014-will-be-a-scorcher/
So much BS. If El Nino returns and sunspots become numerous again there will be warming. But what about the CO2?
I think these guys are doing irrepairable damage to science in general. No wonder the UN uses the Gaia doctrine and the Lucis trust to give them (spiritual?) direction – they don’t trust science any more either.
Cheers
Roger
http://www.thedemiseofchristchurch.com
phlogiston:
I am replying to your post at August 19, 2014 at 2:11 pm which is here.
NO! You have been duped by dp’s propaganda.
“The pause” is the cessation to global warming.
Global warming is an increase to global average surface temperature anomaly (GASTA).
Global warming has stopped.
Global warming is NOT “a change in energy exchanged between” anything.
Indeed, as I explained here with addendum, merely altering the distribution of heat around the Earth’s surface can cause global warming and is a more probable explanation for 20th century global warming that altered atmospheric greenhouse gases.
You and Pamela Gray have ‘lost sight of the pea’. Warmunists are trying to pretend that global warming has not stopped because the oceans are retaining heat. But global warming is about changes to TEMPERATURE and NOT HEAT.
Richard
dp:
At August 19, 2014 at 6:47 pm you ask me
YES! And I explained it to you in my first post in this thread which was addressed to you, which you answered, which is at August 19, 2014 at 9:02 am, and which is here with subsequent addendum.
I there wrote
For many years and in several place (including WUWT) I have been pointing out that redistribution of surface temperature (e.g. by altered ocean currents) could have caused all the 0.8°C global warming over the twentieth century. And Richard Lindzen has pointed it out, too.
Richard
dp, phlogiston and Pamela Gray:
I have replied to the post of dp at August 19, 2014 at 6:47 pm but it has gone into moderation. I post this so you can know of it if you want to look for it as the thread grows.
Richard