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    Major Progress In CO2 And Global Warming Reduction
    By News Staff | January 26th 2013 01:25 PM | 20 comments | Print | E-mail | Track Comments

    At least in America, CO2 emissions have dropped dramatically. The energy sector, the largest producer of CO2, is already back at early 1990s levels of emissions and the traditionally worst offender, coal, is at early 1980s levels.

    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-industrialized level around the year 1750. If we continue to emit greenhouse gases at our current rate, estimates are that we risk doubling that atmospheric CO2 level in roughly 2050.


    Developing nations have easily offset American reduced emissions but industrialized nation reductions may still be good enough, since 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. If confirmed by other studies, this could have far-reaching impacts on efforts to achieve the political targets for climate."

    Temperature rise is leveling 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. 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.

    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.




    The researchers have arrived at an estimate of 1.9°C as the most likely level of warming. Photo: Shutterstock

    Man-made 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.

    Natural changes also a major factor

    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."

    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.


    Comments

    how much of this so-called leveling off from 2000-2010 though, is due to the rapid ice melt in the arctic, causing more extreme cold weather in other regions? given the weather extremes we are increasingly seeing - droughts, bushfires, storms etc, i would be highly skeptical of a report saying its not as bad as most scientists think. you only have to look at the methane now being released from rapid melt in the arctic to realise we still have a problem

    Hank
    You could put any study in a closed logical system like that and debunk it just as easily. There are few accurate temperature readings before 1980, for example, so it is easy for skeptics to claim that the comparisons from the past are off.   We haven't had anywhere near the extremes we had in the 1970s, that's for sure, we just have 24 hour news and storms that elect presidents today. Back then it was just called weather.

    If there are flaws in the study, they come out pretty quickly. Circling a respected researcher with pitchforks is not the way to go. 
    Hank, please what you wrote is just bunk. Few accurate records before 1980? Dr. Richard Muller and his team verified otherwise. Do you believe that? No extremes like we had in the 1970's. Please read Dr. James Hansen's paper that proves otherwise and folks in the drought areas and Hurrican Super storm Sandy feel otherwise.
    Actually, the article is flawed, our emissions really have not gone down. We are just exporting our coal to China and the natural gas from fracking release methane, 10X more heat trapping than CO2.
    So, you can write just about anything you like, but please not this nonsense.

    Hank
    Terms like 'bunk' and 'nonsense' and invoking a storm as evidence show you are in the advocacy camp more than the science one, and that has some value, but it doesn't do any good at all regarding getting constructive policy decisions made.  If you have an issue with the paper, take it up with the researcher.  Call her a shill for Big Oil or wherever you are going next.

    P.S. Methane is 23X the warming impact of CO2.  You got everything else in your comment wrong as well, so I should have let it all go, but I can't help myself.
    Thor Russell
    You can't say methane is x* stronger than CO2 without mentioning a timeframe. Methane has a half life of 7 years, but CO2 doesn't. The average affect of methane over shorter periods of time is greater than over longer times. Just saying it is 23X without mentioning a timeframe is incorrect/misleading.
    Thor Russell
    Hank
    It's neither, by me, I was responding to the statement made by someone else in their context.  Please don't follow up with another comment of minutiae telling me how I should respond to dummies, rather than addressing the dummy themselves.
    Thor Russell
    ? what do you mean "its neither" You specifically said 23*, which is just as wrong as 10*. I wasn't telling you how to respond to the previous commenter, I am not interested in them. 

    My interpretation of your comment and position and I am sure many other people is that you believe methane is 23* stronger than CO2, which is clearly also misleading/wrong and needs to be pointed out. The relative strength of methane vs CO2 is not a minutae and many people make dubious decisions because they are NOT aware that methane because of the half life issues behaves very differently to CO2 in terms of how it affects the 21st century climate.  (e.g. the very topical methane emitted by fracking!) This unhelpful misunderstanding is encouraged whenever someone gives a simple multiplier for methane vs CO2 but doesn't mention half life. If you want to talk sensibly about comparing fracking to coal power, then the half life of methane is an essential concept, not a minutae.
    Thor Russell
    Hank
    I wrote "Methane is 23X the warming impact of CO2". That is a precise statement, whereas 10X was not correct in any way.
    Thor Russell
    The warming impact depends on the timescale, without mentioning timescale, any figure is misleading.

    If you take an approximately 300 year timescale, then methane is 10X stronger. 
    If you take about a 100 year timescale, then methane is 23X stronger, if you take 20 years, its 72* stronger.
    http://en.wikipedia.org/wiki/Greenhouse_gas
    When you don't mention timescale, 10X stronger is every bit as correct/incorrect as 23X stronger.


    If you are talking immediate warming impact, its probably >100* stronger.
    Thor Russell
    Hank
    The warming impact depends on the timescale, without mentioning timescale, any figure is misleading.
    It's not misleading, it is just a way for you to talk. Who doesn't know this? Science 2.0 is not The Daily Mail, there is no one reading this site who does not understand the basics of this...but only two people here are educated by Wikipedia. 
    MikeCrow
    Jeremy, Have you actually looked at the raw data? You personally? Not the homogenized data that bares no resemblance to what was actually measured.
    Never is a long time.
    Yes the evaporation cooling system has been working overtime here on planet earth for some time. I find it fascinating how continue to focus on ways to measure instead of solve. Perfect Planet earth will win, imperfect man will fail. Even a global temperature rise of 2 degrees Celsius will disrupt our lives and challenge our ability to cope. http://clmtr.lt/cb/onZ0eV

    Thor Russell
    Once again, even a skeptic site isn't impressed by papers such as these:
    http://wattsupwiththat.com/2011/12/29/unified-climate-theory-may-confuse...

    Thor Russell
    MikeCrow
    Well, there's a reply to the comments on that thread, it was the second link provided.
    I included those to provide the backup to the last link, which I got to from this post.

    But here's the problem

    Where the red line is the results of the non-co2 based model which is the basis of the various papers, compared to the IPCC's CO2 based models.

    But here's the good news for humanity, and not so good new for AGW


    Even after butchering surface station data, it's obvious the models, and the climate sensitivity they rely on are wrong.
    Never is a long time.
    Thor Russell
    I read the links, and am not convinced by the ozone model etc. I havn't got time to go into it and do it justice in your mind so I will just leave it there. However I have nothing against the suggestion that recent data should lead to the CO2 doubling estimate being revised down. 2-4C was the range, and if it ends up as 2C then I don't consider that wrong. Its entirely possible that some of the temp rise from 1980-2000 was due to the PDO being in a warm phase. 
    To me the global temp with just PDO but no AGW is

    f(x) = sin(x)
    but with AGW it is
    f(x) = 0.8x + sin(x)
    Now with the second graph you get not just no rise, but even a time when temps actually go down. However in no way does that diminish the significance of the 0.8x term in the long run. sin(x) has no effect on the long time average, 0.8x has all the effect.




    The question is, is it 0.8x, 2x, or 0.5x? If you are not sure at what stage on the sin(x) curve you are measuring, then there is uncertainty. Now I think that the actual data in the current decade will tell us quite a bit, and more than advances in modelling in that period. However if there is no warming for 10+ years that in no way disproves the hypothesis because x + sin(x) is flat for quite a while, if sin(x) has a period of decades. It does of course lower the estimate of what a doubling of CO2 will cause, which I am not arguing against. Global heat imbalance and ocean heat content changes are very important measurements to have as there is far more heat energy in the oceans than the atmosphere.

    http://www.skepticalscience.com/The-Earth-continues-to-build-up-heat.html

    If this graph is wrong, its more important than land temperature measurements to me. There is no obvious pause here.

    Thor Russell
    MikeCrow
    The model is a decomposition of actual satellite temperature measurements, based on 5 inputs
    Ozone concentration,Aerosols index, Reflectivity, and Sun spot number, and past temperature record. It results in what looks to be a more accurate output temp than any of the CO2 based models.

    As for the continued build up:
    Because of a lack of data, we use a linear trend for the deep-ocean contribution. For the depth range 700–3000 m for 1955 to 2003, the trends are 0.07 ± 0.1 mm yr−1 and 1 × 1021 J yr−1 [Levitus et al., 2005; Antonov et al., 2005], but these estimates may be biased low because of inadequate deep-ocean sampling, particularly in the early part of the record. Below 3000 m and since the 1980s, the trends are 0.09 ± 0.06 mm yr−1 and 1 × 1021 J yr−1 [Purkey and Johnson, 2010]. There are few long-term observations to indicate if this is a recent or a longer-term trend. Either way, it would contribute less than 5 mm to sea level since 1961 and we use this trend for the full period.

    From Revisiting the Earth's sea-level and energy budgets from 1961 to 2008

    Which is the Church paper listed in your SKS reference.
    New research has been published that finds the planet has continued to build up heat well into the 21st century. Church et al 2011 extends the analysis of Murphy 2009 which calculated the Earth's total heat content through to 2003.


    from here:

    And this


    from here
    So it looks like heat's still accumulating in the models, not not when you go and measure the actual ocean.
    Never is a long time.
    Thor Russell
    I am not convinced by the first model, it shows a short timescale and for that kind of a situation you can fit all sorts of parameters to get a good fit. There have been several models I have seen put forward like that, which fail over a longer scale or are given unrealistic physical assumptions just to fit and of course fail to predict in later years. I expect that if you take the model back to 1900 it won't agree that well anymore. If one parameter e.g. ozone is determined by CO2 or something you can easily get cause and effect wrong. 
    The ocean temps are more interesting, I will look into it and keep it in mind as more data comes in. The argo program will no doubt be useful. 
    http://en.wikipedia.org/wiki/Argo_(oceanography)

    Even if heat is going into the deep ocean, if that pattern continues it will make the heating less that it otherwise would be, though of course when the PDO changes, some of that heat has gone down could come back up again. My prediction is in 10 years time things will be heating up faster than they are now, because natural cycles will be adding not subtracting to CO2 heat trapping but we shall see of course.
    There is definitely still a lot to learn, however it cuts both ways; the arctic ice has melted faster than anyone predicted and uncertainty around a mean isn't a case for inaction.
    Thor Russell
    MikeCrow
    The model is a mathematical model, as opposed to a physical model. But you're right that it might not have a complete set of required inputs yet, and as the missing effect shows up in the temp record the results will start to diverge. But, that in itself doesn't make if ineffective. The model can be retrained with a more extensive temp record and additional inputs to work from.
    BTW, this is really what Newton's equation of gravity is, a mathematical model of gravity, it wasn't until a long time after Newton that a physical basis of gravity was figured out, at the same time the equation became more complex.

    As for Arctic ice, it's melting is just a fancy way to cool the oceans (and it's not unprecedented), Warm water exposed to space radiates far more heat than ice does, and above ~70-80 degrees, the albedo of water is much higher than water at the equator due to Sun light reflecting off it's surface.

    I think we'll be going into a multi-decade cooling period, between the rapid cooling of things like open arctic waters, and the significant reduction of Solar activity, I think it's going to get bad. And if I'm right that much of the increase of atm co2 is from warming waters, co2 will start dropping.

    Which reminds me of something I read, the seasonal variation of CO2 is ~6ppm, while it's been increasing ~1-2ppm/years, so even if that 2 ppm is all human, seasonal variation is still 3+ times as strong.
    Never is a long time.
    MikeCrow
    And then there's
    The new results from the North Greenland Eemian Ice Drilling (NEEM) project, managed by Denmark's Centre for Ice and Climate, show that during the Eemian interglacial, the climate in North Greenland was about 8 degrees Celsius warmer than at present. The Eemian interglacial period began about 130,000 years ago and ended about 115,000 years ago.

    Showing current warming isn't unprecedented. Soot has a bigger impact than expected. Jet contrails cause warming. Waste heat has a bigger impact than expected. Surface temps are suspect and need adjusted 80 years after the fact. The Sun might be a bigger factor than TSI suggests.
    And my own work suggests no loss of nightly cooling, and normal variations far exceed any co2 signal.
    Never is a long time.