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  1. #3136
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by otoc View Post
    You got anything more than a personal statement that "Mars" is getting warmer? Again, is it a global issue, or one from outside forcings? That blog links to scientific studies, btw.

    No comment on
    ??

    You want more? Supply something other than a just simple statement in the form of a question to back your apparent position. I'm in no mood to discuss, let alone argue an opinion of yours, with a game where you want me to do all the work for you simply because you are rigid in a position. I know your position. I've repeatedly read it here. Climate change is a complete swindle/sham/lie in your mind.
    In other words, no, you don't have anything to prove that Mars is getting warmer 'cause of the sun besides a five year old kinda sorta explanation from a blog that links to non-conclusive scientific studies.

    I didn't think so.

  2. #3137
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by Dutchcedar View Post
    In other words, no, you don't have anything <insert>more</insert> to prove that Mars is getting warmer 'cause of the sun besides a five year old kinda sorta explanation from a blog that links to non-conclusive scientific studies.

    I didn't think so.
    lol, fixed it for ya, dutch. Right, I'm not wasting any more time to give you more until you give something to back and actually describe the facts behind your opinion. Until then, you and your little boy taunts can have a great day. Solar activity is down, btw.

  3. #3138
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    Re: The Great Global Warming Thread (merged)

    The question about Mars has been posed many times in this thread, going back to its beginnings in 2007, if I recall correctly. The responses remain very similar.
    Supply something other than a just simple statement in the form of a question to back your apparent position. I'm in no mood to discuss, let alone argue an opinion of yours, with a game where you want me to do all the work for you simply because you are rigid in a position. I know your position. I've repeatedly read it here. Climate change is a complete swindle/sham/lie in your mind.
    Right, I'm not wasting any more time to give you more until you give something to back and actually describe the facts behind your opinion. Until then, you and your little boy taunts can have a great day.
    Very scientific discussions like this are spawned by the mere mention of temperature rising on Mars.

    Its not just here in TLR. Its the same from AGW zealots everywhere.

    At least this time, we weren't replayed the photos of Polar Bears drifting on small ice floes.

    But we do appreciate the blog analysis that predates this entire thread and the usual tizzy fit.

  4. #3139
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by Dutchcedar View Post
    The question about Mars has been posed many times in this thread, going back to its beginnings in 2007, if I recall correctly.
    lol, then it should be easy for you to supply something. Nevermind if I stop this toothpulling of trying to get wtf you base your position on.

    2007 must be a reference to a study by Fenton that referenced work by Gessler in 2005. And you find timelines to be discounted? Gee whiz, dutch, selective as always?

    Fenton's position was about albedo
    Our results suggest that documented albedo changes affect recent climate change and large-scale weather patterns on Mars, and thus albedo variations are a necessary component of future atmospheric and climate studies.

    and was later discounted by Richardson later in 2007.
    Title:
    Some Coolness on Martian Global Warming and Reflections on the Role of Surface Dust Authors:
    Richardson, M. I.; Vasavada, A. R. Affiliation:
    AA(Caltech, 1200 E. California Blvd, Pasadena, CA 91125, United States Publication:
    American Geophysical Union, Fall Meeting 2007, abstract #P31D-05 Publication Date:
    12/2007 Origin:
    AGU AGU Keywords:
    1605 Abrupt/rapid climate change (4901, 8408), 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513), 5445 Meteorology (3346), 5464 Remote sensing, 6225 Mars Bibliographic Code:
    2007AGUFM.P31D..05R Abstract

    Recent comparisons of global snap-shots of Mars' surface taken by the Viking and Mars Global Surveyor (MGS) cameras have been used to suggest that Mars has darkened, and hence has warmed, between the 1970's and 1990's. While this conclusion is not supported by more quantitative analysis of albedo data, the idea of Martian darkening and warming has found its way into the terrestrial climate change debate. Through blogs and other opinion pieces it has been used, both amusingly and disturbingly, to argue that Mars' apparent natural warming should alleviate our concerns about anthropomorphic climate change on Earth. Relating planetary research results to terrestrial analogs is instructive and promotes public understanding, but this example provides a cautionary tale of misinterpretation in this age of politicized science. The dust cycle is the dominant short-term component of the Martian climate. The atmosphere is strongly forced via dust's modification of atmospheric radiative heating rates, while dust loading displays dramatic interannual variability, from background opacity to aperiodic global dust storms. Until recently, the atmospheric component of the dust cycle was better documented than the surface component (which on Mars can be gauged via albedo). But now thanks to the combination of regional imaging, spot thermal infrared spectra, and spot short-wavelength photometry sampled at synoptic time and length scales by MGS, a rich new view of the relationship between specific meteorological phenomena and the patterns of surface dust is emerging. Seasonal cap winds, local, regional, and global dust storms, and monsoonal circulations all redistribute surface dust on large spatial scales, while dust devils are surprisingly shown to be insignificant. Rapid and widespread albedo modification is accomplished by storms that darken relatively bright regions through dust removal, and deposit dust upon largely dust free areas, brightening them. (It is not possible with existing data to infer dust deposition or erosion in perennially dusty areas.) However, most of the dust deposited on darker regions is removed within one Martian year. This rapid cleaning suggests that darker areas retain their dust-free albedo over decadal time scales because any dust deposited there can be eroded at commonly experienced wind speeds. Bright regions recover more slowly, sometimes requiring several martian years. The depletion of these dust sources in some years may play an important role in the interannual variability in dust storm occurrence and intensity by introducing a multiyear "memory" into the system. The observation of the 2001 global storm and its wake allows predictions to be made for the recovery following the 2007 global storm: the southern hemisphere should retain a transient brightening until after the seasonal cap has advanced and retreated. The MGS data show that albedo is a dynamic and evolving meteorologically and climatologically active variable, not a static boundary condition. Overall, the major story that albedo has to tell is one of major dust storms and recovery from them; not of secular changes; and that the changes are mostly cyclic such that surfaces tend to return to their pre-storm albedos. We speculate that this system of fine balances is dynamically controlled, such that interannual occurrence of dust storms and the partial dust coating of the surface should be robust against the expected large changes of orbital parameters throughout Martian geological history.
    Here's another perfect example of Mars temps increasing with a dust storm.
    Mars Express watches a dust storm engulf Mars

    Wed Dec 12, 2007 at 11:14 UTC

    This summer, Mars suffered a titanic dust storm that engulfed the entire planet. The dust storm contributed to a temporary warming effect around Mars, which raised the temperature of the atmosphere by around 20-30C.
    Quote Originally Posted by Dutchcedar View Post
    The responses remain very similar.Very scientific discussions like this are spawned by the mere mention of temperature rising on Mars.

    Its not just here in TLR. Its the same from AGW zealots everywhere.

    At least this time, we weren't replayed the photos of Polar Bears drifting on small ice floes.

    But we do appreciate the blog analysis that predates this entire thread and the usual tizzy fit.
    Funny response. Empty, but funny. I am enjoying your "tizzy fit" though.

  5. #3140
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by Dutchcedar View Post
    The question about Mars has been posed many times in this thread, going back to its beginnings in 2007, if I recall correctly. The responses remain very similar.Very scientific discussions like this are spawned by the mere mention of temperature rising on Mars.

    Its not just here in TLR. Its the same from AGW zealots everywhere.

    At least this time, we weren't replayed the photos of Polar Bears drifting on small ice floes.

    But we do appreciate the blog analysis that predates this entire thread and the usual tizzy fit.
    Funny how all the heating on Mars can be explained away by the cultists as a result of natural phenomena. But here on big blue any implied warming has gotta be man~made.



    The only truth behind MMGW here is that it is indeed "man made"... with the aide of computer models whose predictive (in)accuracy is only equaled in failure by the the very people whom feed the manipulated data into them.

    "The most dangerous myth is the demagoguery that business can be made to pay a larger share, thus relieving the individual. Politicians preaching this are either deliberately dishonest, or economically illiterate, and either one should scare us...
    Only people pay taxes, and people pay as consumers every tax that is assessed against a business."


    -The Gipper


  6. #3141
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    Re: The Great Global Warming Thread (merged)

    ^^^ Well, yeah.

    What strikes me is how the "science" is always political, needs government funding to exist and seems to come from one side of the political fence and one side only.

    I know, we'll soon see a post about how McShame agrees with the cultists.

  7. #3142
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    Re: The Great Global Warming Thread (merged)

    Same can be said of the debunkers.

  8. #3143
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    Re: The Great Global Warming Thread (merged)

    ^^^ Yeah, those debunkers get lots of government cash to push their agenda.

  9. #3144
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    Re: The Great Global Warming Thread (merged)

    The previous administration was pretty apt at it and the lobbies are still pretty flush.

  10. #3145
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by AMDScooter View Post
    Funny how all the heating on Mars can be explained away by the cultists as a result of natural phenomena. But here on big blue any implied warming has gotta be man~made.
    Funny how your thought of a rebuttal is to not provide anything other than a constant whine from the sidelines with nothing in rebuttal. Yes the situation on Mars was explained. You disagree? Great. Provide something other than taunts.

    Quote Originally Posted by AMDScooter View Post


    The only truth behind MMGW here is that it is indeed "man made"... with the aide of computer models whose predictive (in)accuracy is only equaled in failure by the the very people whom feed the manipulated data into them.

    Here we go again. But at least you provided something, if not an anonymous graphic that shows nothing, that states you feel that there has been, let's see now, Global Cooling for the last 12 years?

    At least you aren't waffling and slidestepping like you did last time you were, were not, might be, could be, posting a position that there is not warming and went away after I posted a skeptic's observation that there is in fact warming continuing. So let's post an update from Roy Spencer's blog on the topic from John Christie's sat data....
    July 2010 UAH Global Temperature Update: +0.49 deg. C

    August 3rd, 2010
    YR MON GLOBE NH SH TROPICS
    2009 1 0.251 0.472 0.030 -0.068
    2009 2 0.247 0.565 -0.071 -0.045
    2009 3 0.191 0.324 0.058 -0.159
    2009 4 0.162 0.315 0.008 0.012
    2009 5 0.139 0.161 0.118 -0.059
    2009 6 0.041 -0.021 0.103 0.105
    2009 7 0.429 0.190 0.668 0.506
    2009 8 0.242 0.236 0.248 0.406
    2009 9 0.505 0.597 0.413 0.594
    2009 10 0.362 0.332 0.393 0.383
    2009 11 0.498 0.453 0.543 0.479
    2009 12 0.284 0.358 0.211 0.506
    2010 1 0.648 0.860 0.436 0.681
    2010 2 0.603 0.720 0.486 0.791
    2010 3 0.653 0.850 0.455 0.726
    2010 4 0.501 0.799 0.203 0.633
    2010 5 0.534 0.775 0.292 0.708
    2010 6 0.436 0.550 0.323 0.476
    2010 7 0.489 0.635 0.344 0.422


    The global-average lower tropospheric temperature remained high, +0.49 deg. C in July, 2010, although the tropics continued to cool as La Nina approaches.
    As of Julian Day 212 (end of July), the race for warmest year in the 32-year satellite period of record is still too close to call with 1998 continuing its lead by only 0.07 C:

    YEAR GL NH SH TRPCS
    1998 +0.62 +0.73 +0.51 +0.90
    2010 +0.55 +0.74 +0.36 +0.63

    To exceed 1998 as the warmest year, the daily global average temperature for the remainder of this year (1 Aug to 31 Dec, 2010) will need to average above +0.466 deg. C.
    As a reminder, five months ago we changed to Version 5.3 of our dataset, which accounts for the mismatch between the average seasonal cycle produced by the older MSU and the newer AMSU instruments. This affects the value of the individual monthly departures, but does not affect the year to year variations, and thus the overall trend remains the same as in Version 5.2. ALSOwe have added the NOAA-18 AMSU to the data processing in v5.3, which provides data since June of 2005. The local observation time of NOAA-18 (now close to 2 p.m., ascending node) is similar to that of NASAs Aqua satellite (about 1:30 p.m.). The temperature anomalies listed above have changed somewhat as a result of adding NOAA-18.
    [NOTE: These satellite measurements are not calibrated to surface thermometer data in any way, but instead use on-board redundant precision platinum resistance thermometers (PRTs) carried on the satellite radiometers. The PRT's are individually calibrated in a laboratory before being installed in the instruments.]
    And scoot, note the change in the data set by Spencer, or manipulation as you like to say. Priceless, as is the illusion that there is no warming on a global level when a reasonable trending average, oh sorry, reasonable trending man-made manipulation is done.

  11. #3146
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by otoc View Post
    Funny how your thought of a rebuttal is to not provide anything other than a constant whine from the sidelines with nothing in rebuttal. Yes the situation on Mars was explained. You disagree? Great. Provide something other than taunts.



    Here we go again. But at least you provided something, if not an anonymous graphic that shows nothing, that states you feel that there has been, let's see now, Global Cooling for the last 12 years?

    At least you aren't waffling and slidestepping like you did last time you were, were not, might be, could be, posting a position that there is not warming and went away after I posted a skeptic's observation that there is in fact warming continuing. So let's post an update from Roy Spencer's blog on the topic from John Christie's sat data....


    And scoot, note the change in the data set by Spencer, or manipulation as you like to say. Priceless, as is the illusion that there is no warming on a global level when a reasonable trending average, oh sorry, reasonable trending man-made manipulation is done.
    Righto... Those temps could be adjusted again at any time couldn't they? As I have stated many times, it's been both warmer and cooler and temp adjustments are constantly being made. None of the previous warming or cooling could have possibly been a result of hooman activity.

    MMGW only exists in computer models. I have requested time and again and will do so now.. show me the IPCC approved and "peer reviewed" model that predicted what the global climate has done accurately as a result of that 33bil co2. Let me request in advance you don't link to one of the recently manipulated and "adjusted" realclimate models. Show me a model that made a prediction from say 10 years ago that matches that satellite data you just provided above.

    I eagerly await the usual response...


    **EDIT** In regard to those constant adjustments I mentioned above..

    UAH Global Temperature – still in a holding pattern

    While Sea Surface Temperatures are cooling sharply as shown here, global surface temperature is still oscillating around 0.40 to 0.50C for the last four months. This is not surprising as the air temperature is strongly correlated with the SST but lags behind by about 3 months. Expect drops in the months ahead. – Anthony

    July 2010 UAH Global Temperature Update: +0.49 deg. C

    Br Dr. Roy Spencer, PhD


    The global-average lower tropospheric temperature remained high, +0.49 deg. C in July, 2010, although the tropics continued to cool as La Nina approaches.


    As of Julian Day 212 (end of July), the race for warmest year in the 32-year satellite period of record is still too close to call with 1998 continuing its lead by only 0.07 C:

    YEAR GL NH SH TRPCS
    1998 +0.62 +0.73 +0.51 +0.90
    2010 +0.55 +0.74 +0.36 +0.63

    To exceed 1998 as the warmest year, the daily global average temperature for the remainder of this year (1 Aug to 31 Dec, 2010) will need to average above +0.466 deg. C.

    As a reminder, five months ago we changed to Version 5.3 of our dataset, which accounts for the mismatch between the average seasonal cycle produced by the older MSU and the newer AMSU instruments. This affects the value of the individual monthly departures, but does not affect the year to year variations, and thus the overall trend remains the same as in Version 5.2. ALSO…we have added the NOAA-18 AMSU to the data processing in v5.3, which provides data since June of 2005. The local observation time of NOAA-18 (now close to 2 p.m., ascending node) is similar to that of NASA’s Aqua satellite (about 1:30 p.m.). The temperature anomalies listed above have changed somewhat as a result of adding NOAA-18.

    [NOTE: These satellite measurements are not calibrated to surface thermometer data in any way, but instead use on-board redundant precision platinum resistance thermometers (PRTs) carried on the satellite radiometers. The PRT's are individually calibrated in a laboratory before being installed in the instruments.]


    YR MON GLOBE NH SH TROPICS
    2009 1 0.251 0.472 0.030 -0.068
    2009 2 0.247 0.565 -0.071 -0.045
    2009 3 0.191 0.324 0.058 -0.159
    2009 4 0.162 0.315 0.008 0.012
    2009 5 0.139 0.161 0.118 -0.059
    2009 6 0.041 -0.021 0.103 0.105
    2009 7 0.429 0.190 0.668 0.506
    2009 8 0.242 0.236 0.248 0.406
    2009 9 0.505 0.597 0.413 0.594
    2009 10 0.362 0.332 0.393 0.383
    2009 11 0.498 0.453 0.543 0.479
    2009 12 0.284 0.358 0.211 0.506
    2010 1 0.648 0.860 0.436 0.681
    2010 2 0.603 0.720 0.486 0.791
    2010 3 0.653 0.850 0.455 0.726
    2010 4 0.501 0.799 0.203 0.633
    2010 5 0.534 0.775 0.292 0.708
    2010 6 0.436 0.550 0.323 0.476
    2010 7 0.489 0.635 0.344 0.422
    Last edited by AMDScooter; 08-04-2010 at 04:46 PM.
    "The most dangerous myth is the demagoguery that business can be made to pay a larger share, thus relieving the individual. Politicians preaching this are either deliberately dishonest, or economically illiterate, and either one should scare us...
    Only people pay taxes, and people pay as consumers every tax that is assessed against a business."


    -The Gipper


  12. #3147
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    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by AMDScooter View Post
    Righto... Those temps could be adjusted again at any time couldn't they?
    huh? The posting I used by Spencer? You do realize you've used Spencer via Watts because he is skeptical of man's influence. The point was simple. He shows warming where you say there is cooling and he changes data sets where you criticize the use of data.

    Quote Originally Posted by AMDScooter View Post
    As I have stated many times, it's been both warmer and cooler and temp adjustments are constantly being made. None of the previous warming or cooling could have possibly been a result of hooman activity.
    Sorry, not playing the slidestep game today. Here we go again, just like the last time. This time you posted a graphic that in no uncertain terms stated cooling for the last 12 years. I gave you the latest from Spencer. Warming dude. Whether or not you need to be absolutely convinced it is due to human activity is not the point since you offer nothing to support that opinion of yours. I'm not going to have my time wasted trying to prove or disprove what is in your mind other than to say the various forcings are included in the models.

    Again. You stated cooling. Yet Christy and Spencer show otherwise. If you can't focus on a simple single point you make with the rebuttal I give, for what purpose do you expect me to respond? So you can go in circles? Sorry. Yet again, not playing.

    Quote Originally Posted by AMDScooter View Post
    MMGW only exists in computer models. I have requested time and again and will do so now.. show me the IPCC approved and "peer reviewed" model that predicted what the global climate has done accurately as a result of that 33bil co2.
    DUH. Yeah. And Gravity only exists as a theory. I've linked in the past to articles and now you repeat it again just like you dance around posting a set position that there is cooling for the last decade, show some unrelated anonymous chart and then demand more from others.


    Quote Originally Posted by AMDScooter View Post
    Let me request in advance you don't link to one of the recently manipulated and "adjusted" realclimate models. Show me a model that made a prediction from say 10 years ago that matches that satellite data you just provided above.

    I eagerly await the usual response...
    Oh god, scoot. We go from you stating cooling when there isn't, you ignore the fact that there is warming and you "request" proof of models with the exclusion of climate scientists while you continually post blog entries from anonymous authors with no background in the field as empirical proof. Stop the freaking dual standards for if they continue I'll just say you believe in divine intervention for all climate changes.

    Here's two links with authors noted mostly not associated with RealClimate. But that will end the nonsense for me unless you exclude the weatherman Watts from future posts.
    cont...

  13. #3148
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    Re: The Great Global Warming Thread (merged)

    2. proof

    How reliable are climate models?



    There are two major questions in climate modeling - can they accurately reproduce the past (hindcasting) and can they successfully predict the future? To answer the first question, here is a summary of the IPCC model results of surface temperature from the 1800's - both with and without man-made forcings. All the models are unable to predict recent warming without taking rising CO2 levels into account. Noone has created a general circulation model that can explain climate's behaviour over the past century without CO2 warming.

    Figure 1: Comparison of climate results with observations. (a) represents simulations done with only natural forcings: solar variation and volcanic activity. (b) represents simulations done with anthropogenic forcings: greenhouse gases and sulphate aerosols. (c) was done with both natural and anthropogenic forcings (IPCC).
    Predicting/projecting the future

    A common argument heard is "scientists can't even predict the weather next week - how can they predict the climate years from now". This betrays a misunderstanding of the difference between weather, which is chaotic and unpredictable, and climate which is weather averaged out over time. While you can't predict with certainty whether a coin will land heads or tails, you can predict the statistical results of a large number of coin tosses. In weather terms, you can't predict the exact route a storm will take but the average temperature and precipitation over the whole region is the same regardless of the route.
    There are various difficulties in predicting future climate. The behaviour of the sun is difficult to predict. Short-term disturbances like El Nino or volcanic eruptions are difficult to model. Nevertheless, the major forcings that drive climate are well understood. In 1988, James Hansen projected future temperature trends (Hansen 1988). Those initial projections show good agreement with subsequent observations (Hansen 2006).

    Figure 2: Global surface temperature computed for scenarios A, B, and C, compared with two analyses of observational data (Hansen 2006).
    Hansen's Scenario B (described as the most likely option and most closely matched the level of CO2 emissions) shows close correlation with observed temperatures. Hansen overestimated future CO2 levels by 5 to 10% so if his model were given the correct forcing levels, the match would be even closer. There are deviations from year to year but this is to be expected. The chaotic nature of weather will add noise to the signal but the overall trend is predictable.
    When Mount Pinatubo erupted in 1991, it provided an opportunity to test how successfully models could predict the climate response to the sulfate aerosols injected into the atmosphere. The models accurately forecasted the subsequent global cooling of about 0.5 C soon after the eruption. Furthermore, the radiative, water vapor and dynamical feedbacks included in the models were also quantitatively verified (Hansen 2007). More on predicting the future...

    Figure 3: Observed and simulated global temperature change during Pinatubo eruption. Green is observed temperature by weather stations. Blue is land and ocean temperature. Red is mean model output (Hansen 2007).

    Uncertainties in future projections


    A common misconception is that climate models are biased towards exaggerating the effects from CO2. It bears mentioning that uncertainty can go either way. In fact, in a climate system with net positive feedback, uncertainty is skewed more towards a stronger climate response (Roe 2007). For this reason, many of the IPCC predictions have subsequently been shown to underestimate the climate response. Satellite and tide-gauge measurements show that sea level rise is accelerating faster than IPCC predictions. The average rate of rise for 1993-2008 as measured from satellite is 3.4 millimetres per year while the IPCC Third Assessment Report (TAR) projected a best estimate of 1.9 millimetres per year for the same period. Observations are tracking along the upper range of IPCC sea level projections(Copenhagen Diagnosis 2009).

    Figure 4: Sea level change. Tide gauge data are indicated in red and satellite data in blue. The grey band shows the projections of the IPCC Third Assessment report (Copenhagen Diagnosis 2009).
    Similarly, summertime melting of Arctic sea-ice has accelerated far beyond the expectations of climate models. The area of sea-ice melt during 2007-2009 was about 40% greater than the average prediction from IPCC AR4 climate models. The thickness of Arctic sea ice has also been on a steady decline over the last several decades.


    Figure 5: Observed (red line) and modeled September Arctic sea ice extent in millions of square kilometres. Solid black line gives the average of 13 IPCC AR4 models while dashed black lines represent their range. The 2009 minimum has recently been calculated at 5.10 million km2, the third lowest year on record and still well below the IPCC worst case scenario (Copenhagen Diagnosis 2009).
    Do we know enough to act?

    Skeptics argue that we should wait till climate models are completely certain before we act on reducing CO2 emissions. If we waited for 100% certainty, we would never act. Models are in a constant state of development to include more processes, rely on fewer approximations and increase their resolution as computer power develops. The complex and non-linear nature of climate means there will always be a process of refinement and improvement. The main point is we now know enough to act. Models have evolved to the point where they successfully predict long-term trends and are now developing the ability to predict more chaotic, short-term changes. Multiple lines of evidence, both modeled and empirical, tell us global temperatures will change 3C with a doubling of CO2 (Knutti & Hegerl 2008).
    Models don't need to be exact in every respect to give us an accurate overall trend and its major effects - and we have that now. If you knew there were a 90% chance you'd be in a car crash, you wouldn't get in the car (or at the very least, you'd wear a seatbelt). The IPCC concludes, with a greater than 90% probability, that humans are causing global warming. To wait for 100% certainty before acting is recklessly irresponsible.

    Further reading

  14. #3149
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    Re: The Great Global Warming Thread (merged)

    3. more proof
    Comparing IPCC projections to observations

    The best way to check the reliability of climate models is to compare projections to actual observations. However, this is a catch-22. You need a decent time period to accurately discern climate trends amid the noise of weather fluctuations. Over that time, the climate model would've been superseded by new models running on faster computers at higher resolutions using better understood science. Nevertheless, a paper recently published in Science, Recent Climate Observations Compared to Projections (Rahmstoorf 2007), gives it a shot, comparing 2001 IPCC projections to observations up to 2007.
    This is a short period for comparing climate trends. However, the 2001 model projections were essentially independent from the observed climate data since 1990. Sea-level data were not yet available at the time. Plus the climate models used by the IPCC are physics-based and not "tuned" to reproduce the most recent temperatures.

    CO2 levels

    They start by comparing IPCC projections of CO2 levels to observations at Mauna Loa, Hawaii. Estimating CO2 levels is a complicated business, factoring in economical development, industrial emissions, carbon sinks, etc. The IPCC get it fairly right although you can't credit them too much. A kid with a ruler and some graph paper could've got it fairly right.

    Figure 1: Monthly carbon dioxide concentration (blue thin line) and its long term trend (strong blue line) as measured at Mauna Loa, Hawaii. Dashed line is IPCC's projected carbon dioxide levels.
    Temperature

    More interesting is the comparison of the various IPCC projections of global temperature change (coloured dotted lines) with observations from HadCRUT (blue) and NASA GISS data (red). The thin lines are the observed yearly average. The solid lines are the long term trends, which filter out short term weather fluctuations.

    Figure 2: Global land and ocean surface temperature from GISS (red) and the Hadley Centre/Climatic Research Unit (blue) up to 2006. Thin lines are yearly average, solid lines are long term trends. Dashed lines are IPCC projections. Grey range encompasses IPCC uncertainty in climate sensitivity.
    It's immediately apparent the IPCC underestimated temperature rise with observations warmer than all projections. The paper proposes several possible reasons for the difference. One is intrinsic internal variability which is possible over such a short period. Another candidate is climate forcings other than CO2 such as aerosol cooling being smaller than expected.
    A third candidate is an underestimation of climate sensitivity. The IPCC assumed a climate sensitivity of 3C with an uncertainty range between 1.7 to 4.2C (this is indicated in the grey area of Figure 2). However, there are a number of positive feedbacks in the climate system that are poorly understood and hence not given much influence in IPCC models. Add to this the fact that model uncertainty is inherently skewed towards greater sensitivity. My guess is higher climate sensitivity is part of the story but not all. More on climate sensitivity...
    Sea levels

    IPCC underestimation is even worse when it comes to sea levels, projecting a best-estimate rise of less than 2 mm/year. Satellite data shows a linear trend of 3.3 0.4 mm/year and the tide gauge reconstruction trend is slightly less. Both sets of observations fall well above the IPCC uncertainty range. Again, internal variability may play a part over such a small period. As the largest contributor is ocean thermal expansion, warmer than expected temperatures would be a significant part of the discrepancy. Rapidly increasing melt from Greenland and Antarctica may also contribute although ice sheet contribution is a small part of sea level rise.

    Figure 3: Sea-level data based primarily on tide gauges (annual, red) and from satellite altimeter (3-month data spacing, blue, up to mid-2006) and their trends. Dotted lines are IPCC projections. Grey range encompasses model uncertainty.
    Conclusion

    A common skeptic characterisation of the IPCC is that they exagerate warming projections and the dangers from global warming. In actuality, IPCC projections tend to underestimate climate change, particularly for sea level. Perhaps a more appropriate characterisation is a middle-of-the-road, conservative approach to science.
    Update 27 Mar 2008: Tamino sheds more light on the IPCC projections, contacting Stefan Rahmstorf directly who provided an updated version of his temperature graph:

    Figure 4 courtesy of Tamino: Solid blue and red lines are trends from GISS and HadCRU data, dashed lines are IPCC projections included in the TAR.

  15. #3150
    Joined
    Apr 2002
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    10,810

    Re: The Great Global Warming Thread (merged)

    Quote Originally Posted by AMDScooter View Post
    **EDIT** In regard to those constant adjustments I mentioned above..

    UAH Global Temperature still in a holding pattern
    wtf again scoot. "In regard to those constant adjustments I mentioned above"?

    I already posted the original article by Spencer as proof of continued warming vs your graphic of 12 years of cooling.

    I even highlighted his manipulation, er, adjustment of data in rebuttal to you complaining about how data is used. My point was simple. YOu accept it from some and knock it for others without mercy or understanding.

    So tell me, why did you have to repost that same article I used, because it was via the Watts blog?

    Because he used "holding pattern" in his title?

    Spencer stated the year 2010 is showing to be close to the year 1998. Two selected years and not a trend for the decade which was your point. His chart showed no such thing as 12 years of cooling.

    The trend I'm seeing is you simply argue things around here without even taking the time to read a post from another, or worse, you don't seem to bother to read beyond a title. This is getting ridiculous even for you.

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