Global warming less extreme than feared?
Policymakers are attempting to contain global warming at less than 2°C. New estimates from a Norwegian project on climate calculations indicate this target may be more attainable than many experts have feared.
Internationally renowned climate researcher Caroline Leck of Stockholm University has evaluated the Norwegian project and is enthusiastic.
“These results are truly sensational,” says Dr Leck. “If confirmed by other studies, this could have far-reaching impacts on efforts to achieve the political targets for climate.”
Temperature rise is levelling off
After Earth’s mean surface temperature climbed sharply through the 1990s, the increase has levelled off nearly completely at its 2000 level. Ocean warming also appears to have stabilised somewhat, despite the fact that CO2 emissions and other anthropogenic factors thought to contribute to global warming are still on the rise.
It is the focus on this post-2000 trend that sets the Norwegian researchers’ calculations on global warming apart.
Sensitive to greenhouse gases
Climate sensitivity is a measure of how much the global mean temperature is expected to rise if we continue increasing our emissions of greenhouse gases into the atmosphere.
CO2 is the primary greenhouse gas emitted by human activity. A simple way to measure climate sensitivity is to calculate how much the mean air temperature will rise if we were to double the level of overall CO2 emissions compared to the world’s pre-industrialised level around the year 1750.
If we continue to emit greenhouse gases at our current rate, we risk doubling that atmospheric CO2 level in roughly 2050.
Mutual influences
A number of factors affect the formation of climate development. The complexity of the climate system is further compounded by a phenomenon known as feedback mechanisms, i.e. how factors such as clouds, evaporation, snow and ice mutually affect one another.
Uncertainties about the overall results of feedback mechanisms make it very difficult to predict just how much of the rise in Earth’s mean surface temperature is due to manmade emissions. According to the Intergovernmental Panel on Climate Change (IPCC) the climate sensitivity to doubled atmospheric CO2 levels is probably between 2°C and 4.5°C, with the most probable being 3°C of warming.
In the Norwegian project, however, researchers have arrived at an estimate of 1.9°C as the most likely level of warming.
Manmade climate forcing
“In our project we have worked on finding out the overall effect of all known feedback mechanisms,” says project manager Terje Berntsen, who is a professor at the University of Oslo’s Department of Geosciences and a senior research fellow at the Center for International Climate and Environmental Research – Oslo (CICERO). The project has received funding from the Research Council of Norway’s Large-scale Programme on Climate Change and its Impacts in Norway (NORKLIMA).
“We used a method that enables us to view the entire earth as one giant ‘laboratory’ where humankind has been conducting a collective experiment through our emissions of greenhouse gases and particulates, deforestation, and other activities that affect climate.”
For their analysis, Professor Berntsen and his colleagues entered all the factors contributing to human-induced climate forcings since 1750 into their model. In addition, they entered fluctuations in climate caused by natural factors such as volcanic eruptions and solar activity. They also entered measurements of temperatures taken in the air, on ground, and in the oceans.
The researchers used a single climate model that repeated calculations millions of times in order to form a basis for statistical analysis. Highly advanced calculations based on Bayesian statistics were carried out by statisticians at the Norwegian Computing Center.
2000 figures make the difference
When the researchers at CICERO and the Norwegian Computing Center applied their model and statistics to analyse temperature readings from the air and ocean for the period ending in 2000, they found that climate sensitivity to a doubling of atmospheric CO2 concentration will most likely be 3.7°C, which is somewhat higher than the IPCC prognosis.
But the researchers were surprised when they entered temperatures and other data from the decade 2000-2010 into the model; climate sensitivity was greatly reduced to a “mere” 1.9°C.
Professor Berntsen says this temperature increase will first be upon us only after we reach the doubled level of CO2 concentration (compared to 1750) and maintain that level for an extended time, because the oceans delay the effect by several decades.
The figure of 1.9°C as a prediction of global warming from a doubling of atmospheric CO2 concentration is an average. When researchers instead calculate a probability interval of what will occur, including observations and data up to 2010, they determine with 90% probability that global warming from a doubling of CO2 concentration would lie between 1.2°C and 2.9°C.
This maximum of 2.9°C global warming is substantially lower than many previous calculations have estimated. Thus, when the researchers factor in the observations of temperature trends from 2000 to 2010, they significantly reduce the probability of our experiencing the most dramatic climate change forecast up to now.
Professor Berntsen explains the changed predictions:
“The Earth’s mean temperature rose sharply during the 1990s. This may have caused us to overestimate climate sensitivity.
“We are most likely witnessing natural fluctuations in the climate system – changes that can occur over several decades – and which are coming on top of a long-term warming. The natural changes resulted in a rapid global temperature rise in the 1990s, whereas the natural variations between 2000 and 2010 may have resulted in the levelling off we are observing now.”
Climate issues must be dealt with
Terje Berntsen emphasises that his project’s findings must not be construed as an excuse for complacency in addressing human-induced global warming. The results do indicate, however, that it may be more within our reach to achieve global climate targets than previously thought.
Regardless, the fight cannot be won without implementing substantial climate measures within the next few years.
Sulphate particulates
The project’s researchers may have shed new light on another factor: the effects of sulphur-containing atmospheric particulates.
Burning coal is the main way that humans continue to add to the vast amounts of tiny sulphate particulates in the atmosphere. These particulates can act as condensation nuclei for cloud formation, cooling the climate indirectly by causing more cloud cover, scientists believe. According to this reasoning, if Europe, the US and potentially China reduce their particulate emissions in the coming years as planned, it should actually contribute to more global warming.
But the findings of the Norwegian project indicate that particulate emissions probably have less of an impact on climate through indirect cooling effects than previously thought.
So the good news is that even if we do manage to cut emissions of sulphate particulates in the coming years, global warming will probably be less extreme than feared.
| About the project |
| Geophysicists at the research institute CICERO collaborated with statisticians at the Norwegian Computing Center on a novel approach to global climate calculations in the project “Constraining total feedback in the climate system by observations and models”. The project received funding from the Research Council of Norway’s NORKLIMA programme.The researchers succeeded in reducing uncertainty around the climatic effects of feedback mechanisms, and their findings indicate a lowered estimate of probable global temperature increase as a result of human-induced emissions of greenhouse gases.The project researchers were able to carry out their calculations thanks to the free use of the high-performance computing facility in Oslo under the Norwegian Metacenter for Computational Science (Notur). The research project is a prime example of how collaboration across subject fields can generate surprising new findings. |
- Written by:
- Bård Amundsen/Else Lie. Translation: Darren McKellep/Carol B. Eckmann
- h/t to Andrew Montford via Leo Hickman
anticlimactic says, January 25, 2013 at 3:30 pm: “I see no reason why the exact effect of CO2 doubling could not be measured directly in a lab experiment. It is only sunlight and air so is not a complicated experiment. We can measure temperature changes to a millionth of a degree so any effect could be measured. I doubt if this experiment will be performed as I suspect the answer would be ‘zero’.”
=========================================================
An experiment of the kind has already been performed and your suspicion is justified: http://www.wmconnolley.org.uk/sci/wood_rw.1909.html
Stupid in, stupid out. Come on researchers!!!! It has even been simplified to just include 4 letters! E N S O. But I know. It sucks doesn’t it. To have to admit that you can’t predict the temperature response unless you can match ENSO and atmospheric teleconnection factors. And then you can only go out maybe 5 years. Gee. That would mean that your next grant would depend on how good your prediction was. That must suck too. So much easier to “stupid in, stupid out” and stand in the gravy train of long term gorrific predictions.
Given the degree to which the Earth sequesters cold in the mountain ice fields and polar regions it has tremendous capacity to self-regulate just with joule for joule cancellation. Add to that a variable cap of sea ice that can shrink to allow heat to escape or grow to retain it, we have a one-two punch for stabilization and stable it has been for eons. We have similar capacity to adapt to changes in the composition of the atmosphere. If CO2 increases every living thing grows in numbers to consume it. The weather warms to increase the zone of life – we know that alpine flowers are increasing their range of altitude because the alarmists tell they are escaping the heat. An odd conclusion, to say the least, but a conclusion that supports their flawed world view. They are moving into opportunity.
It is time we quit worrying over the natural climate variations and start worrying over the unnatural variations of climate nutters.
Greg House (to anticlimactic)
An experiment of the kind has already been performed and your suspicion is justified: http://www.wmconnolley.org.uk/sci/wood_rw.1909.html
>>>>>>>>>>>>>>>>
All this time on this blog Greg, all the remarkably gifted physicists who have taken hours of their time to tutor you…. and not just gifted scientists, but ones who most engineering and physics students would be honored just to have met, let alone be tutored by them, and still you cling to your fallacies.
The explanation of the greenhouse effect you link to is entirely correct except that it has NOTHING to do with the greenhouse effect of CO2. They are two completely different physical effects which unfortunately have acquired the same name. Further, even if that were not true, understanding radiative physics on the scale of the atmospheric column cannot possibly be replicated with cardboard boxes.
anticlimactic, I suggest you search this site for articles by Ira Glickstein or search the web for an experiment by Heinz Hugg on Daly’s site (be sure to read the criticisms that accompany the experiment documentation)
Gail Combs says:
January 25, 2013 at 3:50 pm
RMB says: January 25, 2013 at 7:42 am
“You can not heat water from above. surface tension blocks the heat very emphatically and very convincingly. Thats why there is no climate sensitivity.”
>>>>>>>>>>>>>>>>
bones says: January 25, 2013 at 2:21 pm
Baloney. This is the kind of hopelessly wrong stuff that the CAGW sympathisers pray that they will find here.
>>>>>>>>>>>>>>>
When RMB says ‘heat’ he is talking about infrared radiation and therefore he is correct.
But when he says that surface tension has anything to do with it, he is not. It is one thing to say that IR is absorbed in a very thin surface layer (which he did not say), quite another to say that surface tension has anything to do with it and even then, it is incorrect to say that none of that heat is conducted downward.
The researchers used a single climate model that repeated calculations millions of times in order to form a basis for statistical analysis. Highly advanced calculations based on Bayesian statistics were carried out by statisticians at the Norwegian Computing Center.
Oooo…I am in such awe.
“These results are truly sensational,” says Dr Leck. “If confirmed by other studies, this could have far-reaching impacts on efforts to achieve the political targets for climate.”
The global warming movement has done absolutely nothing whatsoever to “achieve” anything, except wasting money and energy. This statement by Leck is self-serving and megalomaniacal.
Desert Yote is right.
Nyar nyar deniers, we’ve finally overcome hiding the decline!
Well you gotta admit they’re persistent little Devils with our taxes and those millions of repeated calculations won’t leave much evidence of their cherry pickin fingers behind them.
Statistics are meaningless if the future does not replicate the past. And why would it? We have introduced an independent variable. Two distinct trends in the satellite era. Which is a satistical model to choose? Well, at least they didn’t average them.
“…and stand in the gravy train of long term gorrific predictions.” Pamela Gray
I’d love it ig someone could make a neat list of all the proud predictions and all subsequent results, all by date on one neat page. The folks need an overview.
davidmhoffer says, January 25, 2013 at 7:13 pm:Greg House (to anticlimactic)
An experiment of the kind has already been performed and your suspicion is justified: http://www.wmconnolley.org.uk/sci/wood_rw.1909.html
>>>>>>>>>>>>>>>>
The explanation of the greenhouse effect you link to is entirely correct except that it has NOTHING to do with the greenhouse effect of CO2. They are two completely different physical effects which unfortunately have acquired the same name.
=========================================================
No, this is not correct.
The experiment by professor Wood dealt exactly with the alleged mechanism of the so called “greenhouse effect” (and debunked it), the IPCC presented 70 years later: back radiation.
The IPCC presented the “greenhouse effect” as warming by back radiation, 70 years after professor Wood demonstrated that this mechanism does not work at all or is negligible. Here is what the IPCC stated: “The Sun powers Earth’s climate, radiating energy at very short wavelengths, predominately in the visible or near-visible (e.g., ultraviolet) part of the spectrum. Roughly one-third of the solar energy that reaches the top of Earth’s atmosphere is reflected directly back to space. The remaining two-thirds is absorbed by the surface and, to a lesser extent, by the atmosphere. To balance the absorbed incoming energy, the Earth must, on average, radiate the same amount of energy back to space. Because the Earth is much colder than the Sun, it radiates at much longer wavelengths, primarily in the infrared part of the spectrum (see Figure 1). Much of this thermal radiation emitted by the land and ocean is absorbed by the atmosphere, including clouds, and reradiated back to Earth. This is called the greenhouse effect.” http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-1-3.html .
Every person is, of course, entitled to invent his/her own private “greenhouse effect” allegedly working differently, but it is the IPCC version which is politically relevant, because certain policies are based exactly on the IPCC reports and not on davidmhoffer’s or other blog users’ versions.
Mosher says…”And sensitivity to 2x c02 cannot be zero. If it were then changes in solar input would be zero.”
Why? How many logical fallacies can you break in one sentance? There are two primary factors in maintaing any system at a steady T. One is the amount of energy going in, The other is the residence time of said energy. Enery itself is immortal. Therefore the bigger the increase in residence time, while input remains constant, the greater the increase in T.
Light a volcano in Iceland for two hundred days and watch most of that energy leave the earth’s surface ocean.land, and atmospheric system fairly quickly. Have that same volcano go off at the bottom of the ocean and almost all the energy released from the mantel is still within the earths system, accumalating every day for the entire period. Hold a match size flame on the side of a pot near the top and you will never much affect the T of the water in the pot; place that same flame under the pot with a raised bottom and watch the T cont to rise. Stating that only the W/M 2 input mattters, is poor science indeed.
Gail, much of your comment and charts showing how deep disparate solar radiation penetrates into the ocean deovetails perfectly with my comments on residence time. BTW, the chart is not correct in that the dyspotic zone of sunlight in the deep tropical oceans is about 800′, So what is the residence time of the different solar spectrum reeaching below the ocean surface?
re bones says:
January 25, 2013 at 7:39 pm
—————————————————————–
Nobody said none of the energy is conducted down, just very little. Most goes to evaporation, which increases WV, which decreases radiation reaching the surface by about 30% in a clear sky, let alone when that WV forms clouds, convecting heat up (Thunderstorms) to radiate away, while preventing radiation from reaching the surface, let alone below the surface. So you tell me the net affect of all this. ( I left out dozens of factors) You would be the first as the IPCC can not, the LWarmers can not, the sceptics can not. It is ok to say we do not know, but the observations do not support CAGW theory.
There was a young lady several years ago (16 at the time I think) who wrote an excellent piece on “Global Warming” or “Climate Change” if you will, and why she thought it was cyclical. I used to have it bookmarked but after several computer changes and one stolen, it is gone. I have searched my backups and it just isn’t popping up. From what I recall, she was pretty dead on with what a lot of highly educated and well trained people are now starting to say but she was WAY, WAY ahead of the curve. I wonder if anyone knows what became of her and whether she has been swayed in her opinion. She did an excellent presentation. I see similar presentations here now, but hers was years ago.
Anyone remember?
If you make your living by producing a climate model and running it on a supercomputer then there is a limit to how far from reality you can let your model get before it starts to look completely ridiculous and your funding is endangered. We’ve now reached that point with a number of these models. We are now seeing new models produced with somewhat less crazy numbers, and older models coming under pressure to adjust their predictions downwards to be less at odds with reality.
But models are still very much a game of “tell me what number you want”. There are so many adjustable parameters assumptions and simplifications in these things that you can make them predict pretty much anything. So although there will be lots of scientific talk about measurements requiring adjusted parameters and newly discovered feedbacks and whatnot to explain all the changes, underneath it all this is still just a bidding game where people pick numbers which are big enough to be alarming so they’ll get funded, but not too big lest people start to laugh.
Henry@Willis
I think to explain the phenomena of why the oceans do not get warmer than 30-33C
When the top layer of molecules of the water in the reservoir reaches a certain temp., namely the boiling point at ruling pressure, it simply evaporates and thereby it cools the remaining liquid in the reservoir. Namely to change state from liquid to gas causes (strong) cooling on the surface that is left. I find the same thing in my swimming pool. Water heated by the sun seldom gets higher than 30-33 but evaporation increases tremendously as we go from, say, 27 to 32….
When water vapor condenses to form clouds and rain, all heat that was taken is put back in the atmosphere. This also helps earth keep the temperature of the planet evenly spread.
Is it not amazing how this planet was put together.
Wayne, you write “Anyone remember?”
I remember her very well indeed, but cannot recall her name. If it comes back to me, I will post again. As I recall what happened was that there was so much negative publicity that her father persuaded her to cease and desist from what she was doing.
Greg House;
Every person is, of course, entitled to invent his/her own private “greenhouse effect” allegedly working differently, but it is the IPCC version which is politically relevant, because certain policies are based exactly on the IPCC reports and not on davidmhoffer’s or other blog users’ versions.
>>>>>>>>>>>>>
The IPCC version is correct, The idiocy you linked to has nothing to do with what the IPCC says and the rest of your bloviating is nothing more than sl@yer sh!t reworded which Anthony has thankfully banned. The problem with the IPCC is the magnitude of the direct ghe from co2 and the magnitude and sign of feedbacks. I’ve no interest in discussing further with you, I simply directed readers to articles that deal with the actual physics of the matter rather than letting them be misled by someone who repeatedly demonstrated that the very basics of physics are either beyond his ability to understand or subject to some deliberate attempt to remain ignorant in the face of facts, a trait you sure with the most ardent of warmist alarmists.
“But the findings of the Norwegian project indicate that particulate emissions probably have less of an impact on climate through indirect cooling effects than previously thought.”
Well, the AGW proponents aren’t going to like hearing that. If particulate emissions don’t have the cooling effect that AGW proponents think, they’ll have to look around for another explanation for their models inability to match observations.
“In the Norwegian project, however, researchers have arrived at an estimate of 1.9°C as the most likely level of warming.”
“If we continue to emit greenhouse gases at our current rate, we risk doubling that atmospheric CO2 level in roughly 2050.”
Doesn’t that mean, if CO2 is logrithmic in effect, that we should have already seen roughly 60% of that warming by now (meaning we should be 1.14C warmer now than when the atmosphere contained 280ppm? Is it?
I suspect we will continue the accelerated emission of CO2 courtesy of China and India, the rate of emission won’t remain constant at all.
Here is a little ‘gem’ from Guardian
http://www.guardian.co.uk/science/2009/sep/03/arctic-temperatures-climate-change#_
‘explaining’ it all. 🙂
HenryP says:
January 26, 2013 at 3:12 am
“I think to explain the phenomena of why the oceans do not get warmer than 30-33C
When the top layer of molecules of the water in the reservoir reaches a certain temp., namely the boiling point at ruling pressure, it simply evaporates and thereby it cools the remaining liquid in the reservoir.”
At the equator surface temperatures are limited by the local wet adiabatic lapse rate to 30C because any excess above that infringes the lapse rate and causes immediate intensification of the thunderstorm belt at the intertropical convergence zone which moves heat to the top of the troposphere and controls surface temperatures in that region.
@ur momisugly Wayne Delbeke; It was Kristen Byrnes, and her original work was called “Ponder the Maunder”. The website doesn’t seem to be available, but I think you can find excerpts, and some additional writings of hers, in addition to an NPR interview she did in 2008. A very bright young lady. Her interest in climate was only a passing one. She only did Ponder for extra credit, and I don’t believe she expected to find what she did, nor was she expecting the amount of attention she got from it.
Wayne Delbeke says:
January 25, 2013 at 11:22 pm
You’re probably thinking of Kristen Byrnes. Her web site is down, I don’t have time at the moment to see if the content is elsewhere.
http://wattsupwiththat.com/2008/04/15/kristen-byrnes-interview-on-npr/
The NPR story is still up.
There might be something hanging off http://www.zimbio.com/Ponder+the+Maunder
I was going to surevey the NH USHCN stations for the Surface stations project, but she beat me to it.