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Thread: Climate Change / Global Warming Discussion

  1. #1881
    Member tigerade's Avatar
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    For Flash:
    For example, speaking of Antarctic ice, just last month Nature reported this:
    If climate science were a religion as you have previously claimed, the scientists might have said something like "There was no error, there never has been an error and we have been infallible the whole time". Instead these scientists said "We made a mistake, it's already been corrected, but we are agnokwoledging the existance of the error". That is perfectly fine, what else would you have them do? I respect someone that admits a mistake or imperfection and seeks to correct that and make it better. In fact, if we were unwilling to address our own errors, science just wouldn't be what it is today. It's not about protecting ego's or someone's personal confidence, it's about trying to constantly refine and improve our body of knowledge. A body of knowledge that I am very much in favor of accumulating further.

    they all draw from the same relatively small pool of primary data sets -- air temp, ocean temp, sea ice extent, etc. What I have seen of the quality and stewardship of these data does not inspire confidence.
    As opposed to what? Ignorance? Are there better data sets that you are aware of? What is the alternative? A foggy picture is clearer than no picture at all. Again this is all opinion. No one expects for data to be perfect all day every day. There are mechanisms built in to uphold the integrity of data, such as dealing with ice core impurities which I'll talk about in a minute. Pretty Good Data > No data. Inferring evidence from pretty gooid data != wild guess.

    (2) Climate science is necessarily anecdotal. We only have one planet, and it only has one history -- with ice ages, sunspot cycles, volcanoes and countless other confounding variables. It would be great if we could do a real AGW experiment: start with 100 identical Earths, 50 with human CO2 emissions and 50 without, and see whether there's a statistically significant difference after 100 years. Absent that luxury, we can only reason anecdotally and ex post facto about the one Earth we have. That very uniqueness also argues for erring on the side of caution, which is why I support lowering our overall footprint whether we fully understand it or not.
    I agree that such as a experiment would be ideal, but of course we do not live in an ideal universe where knowledge is handed to us on a silver platter. However I do think that looking for clues in the past and inferring from what we can find is more helpful than nothing.

    This article talks about how we can estimate past temperatures and past composition of the atmosphere from ice cores. Notice that the article also has links to how they take isotope measurements and their gas analysis techniques. I think this is very helpful.
    What does past climate change tell us about global warming?

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    And this article, from the same organization, addresses the question of ice core impurities and how they are handled:
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    We also know the Earth wobbles in the Earth's orbit around the sun via the Milankovitch cycles:
    http://www.sciencecourseware.org/eec.../Milankovitch/

    How Milankovitch cycles drive climate change:
    Milankovitch Cycles

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    But Milankovich cycles don't explain current warming, in fact the planet was cooling for the past 6,000 years:
    A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
    Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
    Climate Change - isn't it natural?
    5. Climate Change -- isnt it natural? - YouTube
    A Climate Minute - Natural Cycle - YouTube

    Here a couple studies about how temperature rise lags CO2 rise:
    Synchronous Change of Atmospheric CO2 and Antarctic Temperature During the Last Deglacial Warming
    Understanding the role of atmospheric CO2 during past climate changes requires clear knowledge of how it varies in time relative to temperature. Antarctic ice cores preserve highly resolved records of atmospheric CO2 and Antarctic temperature for the past 800,000 years. Here we propose a revised relative age scale for the concentration of atmospheric CO2 and Antarctic temperature for the last deglacial warming, using data from five Antarctic ice cores. We infer the phasing between CO2 concentration and Antarctic temperature at four times when their trends change abruptly. We find no significant asynchrony between them, indicating that Antarctic temperature did not begin to rise hundreds of years before the concentration of atmospheric CO2, as has been suggested by earlier studies.
    http://www.nature.com/nature/journal...ture10915.html
    The covariation of carbon dioxide (CO2) concentration and temperature in Antarctic ice-core records suggests a close link between CO2 and climate during the Pleistocene ice ages. The role and relative importance of CO2 in producing these climate changes remains unclear, however, in part because the ice-core deuterium record reflects local rather than global temperature. Here we construct a record of global surface temperature from 80 proxy records and show that temperature is correlated with and generally lags CO2 during the last (that is, the most recent) deglaciation. Differences between the respective temperature changes of the Northern Hemisphere and Southern Hemisphere parallel variations in the strength of the Atlantic meridional overturning circulation recorded in marine sediments. These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.
    There are other ways to change the climate naturally, and that has happened:

    The End-Permian mass extinction:
    High-precision timeline for Earth’s most severe extinction
    End-Permian Mass Extinction Took Only 60,000 Years, Say Researchers | Paleontology | Sci-News.com

    Cretaceous–Paleogene mass extinction:
    Extinction patterns, δ18 O trends, and magnetostratigraphy from a southern high-latitude Cretaceous–Paleogene section: Links with Deccan volcanism
    Princeton University - Massive volcanoes, meteorite impacts delivered one-two death punch to dinosaurs

    However, there is currently no evidence that volcanoes are causing the rapid rise in CO2:
    Do volcanoes emit more CO2 than humans?

    So in short, that's two alternate explanations for global warming that just aren't adequate - Volcanoes. If volcanoes were causing the rising CO2 levels, then why did they start doing that around the start of the industrial revolution? And why is it that rising CO2 levels in the atmosphere fit so closely the amount of CO2 that humans are emitting in the atmosphere?

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    Also, how could current warming be blamed on the Milankovitch cycles if we were cooling for the past 6000 years but started warming around 150 years ago?
    Milankovitch Cycles OSS Foundation

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    Then the third possible explanation for global warming - the sun. What if global warming is being caused by the sun? If so, we would be able to see some kind of correlation - but we don't.

    Sun & climate: moving in opposite directions

    Solar activity and temperature are headed in two different directions.
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    So that's a few alternative explanations for global warming that can easily be ruled out. But they are not the only alternative explanations, and that brings me to my next point.

    (3) Yes, there is a trust component. Climate science, today, self-selects for believers. I would be more inclined to trust both the quality of the data and the interpretation of that data if the scientists themselves were all incurable skeptics, constantly looking for any systematic bias, cause-effect inversion, or alternative hypothesis. That work is left to "crackpots" now, which does not serve the science or the public well.
    That is quite an audacious claim. What is it that makes you believe that climate scientists are not intellectually honest, and that they suffer from confirmation bias and group think? The same could just as easily be said about the skeptics, could it not? But I think you raise an important point. You central argument there seems to be that there has no honest debate within the scientific community about climate change, and that they are either intentionally or unintentionally corrupting their research. Again, a very bold claim. However it is easily and demonstrably false. There was a LOT of debate about climate change, and there still is. I will give you a small taste:

    The scientific debate on climate change:
    1. Climate Change -- the scientific debate - YouTube

    The History of Climate Science
    Skepticism: Arrhenius vs. Ångström
    The findings did meet with a lot of skepticism during the early 20th Century: the objections were centered around claims of oversimplification, failure to factor in changes in cloudiness, and results of laboratory tests by another Swede, Knut Ångström (1857-1910). Ångström instructed a laboratory assistant to measure the passage of infra-red radiation through a tube filled with carbon dioxide. The tests began with slightly lower amounts of the gas than would be found in a complete section of the atmosphere from top to bottom - although to truly represent the atmosphere, a 250 cm tube, as opposed to the 30 cm one that was used, would have been closer to the mark. Then, the amount of carbon dioxide was reduced by a third: they found what they regarded as very little change and came to the conclusion that the absorption bands of the light spectrum at which carbon dioxide absorbs were quickly saturated - clogged-up, so that their absorption would not increase.
    Another problem raised at the time was that water vapor also absorbs infra-red radiation, and in the available and by modern standards rather low-resolution spectrographs of the time, the absorption bands of the two gases overlapped one another. It was thought, therefore, that increasing carbon dioxide would be countered by it being unable to absorb infra-red radiation in bands of the spectrum that the much more abundant water vapor was already blocking.

    However, the precision of the measurements obtained by Ångström has since been shown to have been poor: his reported decrease of absorption accompanying a 33% decrease in carbon dioxide concentration was 0.4%, when it would in reality be about 1%, enough to make a significant change to planetary temperatures. Not only that, total saturation in the lower atmosphere is not a problem for the Greenhouse Effect: if the upper layers of the atmosphere remain unsaturated, they will still prevent heat getting out into space. The atmosphere cannot simply be treated as a tube full of gas: it has multiple layers, each with its own properties, and how these layers interact is important.

    But back then, it was concluded that Arrhenius was wrong and Ångström moved onto other research, despite Arrhenius publishing a paper critical of the experiments and explaining how in the dry upper atmospheric layers, the role of water vapour was of limited importance. This was - and still is - because water vapor in the upper troposphere occurs in concentrations several orders of magnitude less than in the lower troposphere where most of our weather occurs. As luck would have it, however, nobody took a lot of notice of that and, in effect, the carbon dioxide greenhouse effect hypothesis went to sleep for over two decades.
    Despite such advances, much doubt was still expressed in the scientific community: climatologist Helmut Landsberg commented in 1970 that the rise of CO2 at the then rate might bring a 2°C rise in temperature over the coming four centuries. This, he felt, could "hardly be called cataclysmic." It was also pointed out, by climatologist Hubert Lamb among others, that the uncertainties included a failure to explain previous temperature fluctuations, known from historical data, over the previous centuries. In addition, temperatures had declined a little since the 1940s yet carbon dioxide levels had increased. What was that about? S. Ichtiaque Rasool and Stephen Schneider of NASA, for example, modelled the effects of pollution in the form of aerosols and sulphur emissions in the atmosphere and discovered that a significant increase of such pollution could - possibly - lead to a cooling episode. Such findings even led to a small minority of scientists and a larger number of commentators musing over whether the current interglacial was coming to an end. Were we about to enter a new ice-age? The media loved that one: despite being a minority view, it was nice and dramatic, thereby making news headlines.

    As for your last part..

    Finally, on the question of belief vs. skepticism vs. denial, let me put it this way: if climate change were a stock that we could trade, a believer would buy it, a denier would sell it, and a skeptic wouldn't touch it. I am in the latter camp. If I had to put money on it, I wouldn't, one way or the other. If you put a gun to my head and forced me to either buy or sell, I'd buy, if that's any consolation.
    On your last point - again this is opinion. Why are you telling us your personal feelings on the matter? I strongly have argued, and still do... that is the evidence that should pursuade, not a personal argument. Please don't try harder to appeal to our emotions. Show us the evidence that you think is compelling and any alternative explanation for global warming that you think is plausible. And enough with the gun stuff, this isn't drama class.

  2. #1882
    Senior Member Raffy.Roma's Avatar
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    Great post Tiger. In your post I would like to point out the fact that in the last 800.000 years the Temperature Anomaly has always risen when the concentration of CO2 and CH4 increased. I also would like to say that each Ice Age in the last 800.000 years happened in correspondance of a peak of the Temperature Anomaly and that in the last 800.000 years the concentration of CO2 in the atmosphere that we have today of 400 ppm was never achieved (maximum 300 ppm).

    So what are we waiting for to lower the CO2 concentration in the atmosphere? I don't think that anybody want another Ice Age within the next century.
    PLEASE NOTE: Posts are the copyrighted intellectual property of the author and are intended as part of a conversation within this forum. My words may NOT be quoted outside this forum without my expressed consent.

  3. #1883
    Member tigerade's Avatar
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    China creating the world's largest carbon trading market in 2016 (cap and trade)
    Log In - The New York Times
    Last edited by tigerade; Today at 06:54 PM.

  4. #1884
    Senior Member dhrivnak's Avatar
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    Quote Originally Posted by Raffy.Roma View Post

    So what are we waiting for to lower the CO2 concentration in the atmosphere? I don't think that anybody want another Ice Age within the next century.
    Raffy If you think reducing CO2 is difficult, try taking out of the atmosphere. That is a MUCH more costly and difficult. Let's focus on moving to electric vehicles and solar PV to power them. Maybe you can be the one to show Italians how it can be done.

  5. #1885
    Senior Member Raffy.Roma's Avatar
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    Quote Originally Posted by dhrivnak View Post
    Raffy If you think reducing CO2 is difficult, try taking out of the atmosphere. That is a MUCH more costly and difficult. Let's focus on moving to electric vehicles and solar PV to power them. Maybe you can be the one to show Italians how it can be done.
    You are right David. In fact I am always advertizing electric vehicles and solar PV in Italy but here there is almost no interest at all for this matter. In particular people are not available to spend money in advance for these technologies and don't consider the Climate Change/Global Warming issue a real threat. IMO an intervention (incentives and so on concerning electric vehicles and solar PV) at Government level in Italy would be needed to get some results with respect to this matter.
    PLEASE NOTE: Posts are the copyrighted intellectual property of the author and are intended as part of a conversation within this forum. My words may NOT be quoted outside this forum without my expressed consent.

  6. #1886
    Member tigerade's Avatar
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    Rep message I got - "Wow VERY well put! I assume you do not mind me sharing part of your answer."

    I don't know who "me" is, but yes you are very much welcome. It did take about an hour or two this morning to make that post. I did not do it to necessarily persuade Flash, but to show all of you how to look for the wealth of information available with scientific organizations' websites as well as reading abstracts from scientific papers. The paper may be behind a paywall but almost all the time you can read the abstract. Finding legitimate scientific research is an increasingly important skill in an era where this is such motivation to mislead people on science. If I inspired anyone's curiosity, pushed anyone to have a greater desire to find evidence and good information, that I'm very happy to hear that.

    Now back to climate stuff:

    China Could Reach 100 GW Of PV Capacity By 2018

    China is aiming for 100GW of Solar PV in 2018. To put that in perspective, the whole world passed the 100GW in Mid-2013. So China wants to have us much solar PV installed in 2018 as the entire world did in 2013, that is a crazy amount of solar.

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