I’m no expert, but a century worth of data shows the change in global temperatures:


Global Annual Mean Surface Air Temperature Change

Source: NASA


Global Air Temperature

Source: Climatic Research Unit : Information sheets


Global Temperatures of the Last Five Centuries

Source: NOAA Paleoclimatology Program


Global Glacier Thickness Change

Source: The National Snow and Ice Data Center, Cryospheric Research Since 1976 University of Colorado


Sea Ice Decline Intensifies

Source: The National Snow and Ice Data Center, Cryospheric Research Since 1976 University of Colorado


Sea Level Change

Source: University of Colorado at Boulder


Proxy Temperature Studies

Source: NOAA

Category: Data Analysis, Digital Media, Science, Technical Analysis

Please use the comments to demonstrate your own ignorance, unfamiliarity with empirical data and lack of respect for scientific knowledge. Be sure to create straw men and argue against things I have neither said nor implied. If you could repeat previously discredited memes or steer the conversation into irrelevant, off topic discussions, it would be appreciated. Lastly, kindly forgo all civility in your discourse . . . you are, after all, anonymous.

24 Responses to “Global Warming? What Evidence Do You Have?”

  1. bell8865 says:


    As a believer (and I believe you probably are too) in the quality of data, I would suggest you review this site and then tell me how we can rely on this data to draw conclusions like the above.

    This issue is politically motivated and the faulty data collection methodology leaves a lot to be desired. This site details the issues in painstaking detail. After reviewing this, let me know if you change your mind.


  2. KidHorn says:

    You don’t get it. No one questions whether or not temperatures are rising. The question is whether this is being caused by increased CO2 emissions from burning fossil fuels. Since there are millions of variables involved with weather, there’s no way to prove the connection between increased CO2 and increased temperature. After all, there were times in earths history when temperatures went up without humans burning fossil fuels. It might just be a big coincidence. If you disagree with me, you’re being unamerican and siding with those terrorists who want the Saudi government to fail.

  3. Blif says:

    To me this is the biggest (long run) economic issue hiding in plain site. This article was written before the latest IPCC report. All predictions and modeling has proven overly optimistic since then:

  4. tom brakke says:

    The political and scientific aspects of this will continue to be debated by those on both sides. In the meantime, people that are charged with valuing businesses need to think through the ramifications for analysis:


  5. slimsam says:

    Thank God people in the early 1900′s weren’t doing everything they could to RAISE global temperatures. Little did they know that their 100 DECLINE in global temps was about to stop, and start to go back up..

    Lets hope the people of the early 2000′s don’t do anything to start COOLING the planet.. This will only compound the problem when mother nature starts to cool the planet back down again soon (like she has been doing for the past 11 years)…

  6. tedstevens says:

    wtf Barry…

    1. how old *do you think* then planet is?
    2. what percentage of the above number is 200 years?
    3. evidence showing the net effect of MMGW…anyone anyone bueller?

    Barry…quality over quantity…don’t turn this into a spam blog…boooooooooooo!!!

  7. CaptiousNut says:


    But what, isn’t the Earth something like 4.5 billion years old?

    How highly would you esteem a scientist pontificating on the stock market from an hour’s worth of price action?

  8. mhm says:

    This another evidence that a branch of “science” is becoming the new religion… the fall from the Enlightenment, of sorts.

    So humanity sinned again and mother earth is displeased. All must repent and refute/destroy evil machines that polluted the paradise, the garden of eden that was earth before men created the combustion engine. Or else, Flood 2.0 will undo us all.

    What next, Gore will build an Ark? Can’t use wood (trees are people too). Actually, where is he now?…

  9. gregh says:

    1. Ice cores show a positive correlation tween co2 and heat.
    2. Humans are releasing c02 at an unnatural rate (rates not seen on the planet since humans have been walking upright).
    3. Too much c02 could cause the earth to heat in a way that interrupts natural equilibrium quickly turning green parts of the planet into desert and wrecking havoc in other places.

    So how much c02 is too much? that is the big question. If we have trouble answering this question do we just ignore the problem?

  10. tedstevens says:


    1. Ice cores show a positive correlation tween co2 and heat.
    2. Humans are releasing c02 at an unnatural rate (rates not seen on the planet since humans have been walking upright).

    given 1 and 2 above…wouldn’t this be a logical 3?

    3. net global ice core is decreasing

  11. gregh says:

    Ted, my ice core mention was just a way of saying that globally scientists are 99% sure that greenhouse gases and earth heat are related. I wasn’t refering to ice cores in the context of ice melting.

    Ice cores can be drilled centuries deep, greenhouse gases are trapped in the layers and can be measured across centuries. Earth temps can also be extrapolated from these drilled cores across centuries… the pattern shows more co2 and temperate in lock-step like gld and inflation.

    ok, back to the bailouts

  12. Brendan says:

    I don’t see the point in arguing this. It seems to me that this argument is just perpetuated by those who have vested interest in continuing to use fossil fuels to distract from the real problems with fossil fuels, and by people who are fooled by the rhetoric. Global warming continues to be a science that is hard to pinpoint, so an argument can keep being made that the current thinking MIGHT be wrong. The sad thing is that those on the other side of the argument keep falling for it, rather than shifting the discussion to the many things that are definitely wrong with fossil fuels.

    The bottom line is burning fossil fuels has many, many proven problems. Number one on the list is adverse health affects. Not only does this reduce the quality of life, but also has an enormous economic impact. There is no question that the biproducts of burning things like coal, including sulfer dioxide in the air that cause and/or exacerbate breathing problems, acidified rain that causes structural damage, fish stocks directly damaged by mercury, fish stocks damaged by bleaching of coral, etc., etc., etc. have economic and quality of life impacts that exceed the cost of implementing other solutions that exist today. Basically everyone gets to subsidize the coal and oil industry by paying more for health insurance and by living in lower quality air, eating lower quality food, etc. And this doesn’t take into account the enormous subsidized costs for protecting the shipping and extraction of oil on the ocean and throughout the world. So whether or not global warming exists/is-a-problem/is-caused-by-human-activity the bottom line is that there are plenty of reasons to move to renewable energy. Possibly preventing a global warming catastrophe is just icing on the cake. Whether you are are on the right or the left, you should be for moving to renewables, either because they are a social issue that improves the quality of life, or because you believe in order for free markets to work, the external costs must be paid for by the beneficiary to allow for fair market competition. At 10 years old, these articles ring truer today than they did when written (as you read these, recall how much health care costs have increased in the last 10 years).

  13. gregh says:

    What is a discussion on this site without chart porn?

    on ice core data – awesome chart from the Intergovernmental Panel on Climate Change, 1997. I love the axis label – “time before 2005″. This chart is concentrations over 10,000 years paired with radiative forcings*


    radiative forcings*
    Radiative forcing is a measure of the influence that a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system and is an
    index of the importance of the factor as a potential climate change mechanism. Positive forcing tends to warm the surface while negative forcing tends to cool it. In
    this report, radiative forcing values are for 2005 relative to pre-industrial conditions defined at 1750 and are expressed in watts per square metre (W m–2).

  14. Simon says:

    I believe the globe is warming, I believe that burning fossil fuel is the cause. I don’t believe we know enough to predict more than a short distance in to the future. 25 years max.

    I hope that our planet has stability loops that will kick in before she gets too hot. For example with a high surface temperature you would expect air moisture content to become very high. Water vapor is a green house gas, and traps heat. But it also forms clouds which reflect heat. At some point hopefully cloud cover would start reflecting heat more significantly than the heat trapped by them.

    Before that point it could become awfully hot and damp. Perhaps we might see some large lizards making a come back? Dick Fuld looks a bit like a lizard to me.

  15. schadenfreude says:

    Barry, Barry, Barry,
    Honestly, have you looked at the evidence from the other side?
    Global warming (in the last half-century) is a fact. The notion that it is caused by anthropogenic greenhouse gases is a THEORY and a very poorly supported one at that. Here’s a good place to begin the de-brainwashing process…


  16. Archiphage says:

    NASA… as in *this* NASA?


    BR: Do you think citing an editorial somehow disproves decades of scientific measurement?

  17. culion says:

    Barry, simply presenting charts without any discussion is a bit like saying the market will go up tomorrow without presenting any analysis. These charts and their deficiencies have been discussed in many places from peer reviewed journals to newspaper articles. Charts and poor data come and go (recall the now debunked hockey stick that Gore and the IPCC hung their hat on). Likewise ‘consensus’ scares come and go (recall the ‘global cooling’ warnings of the seventies).

    There are many questions about climate change that are unanswered. As you contemplate the charts (some of the comments and links above will help) here are a couple of simple observations to think about that are not mentioned too often in the smoke and mirrors world of media hype and political hand waving:

    1. The earth has been warming since the Little Ice Age around 1825 (that is what happens when the earth leaves an ice age) at a roughly linear rate of .5 degrees C/century versus the current rate which is slightly higher. Does it seem reasonable that one should subtract the natural rise in temperature from the current observations in order to determine how much additional warming is due to ‘modern’ human activities and if so has this been done?

    2. Although temperature has on average increased linearly since the Little Ice Age there are periods that all agree are different. For example, from 1910 to 1940 temperatures increased but from 1940 to 1975 temperatures decreased (here comes the ‘global cooling’ uproar) in spite of an increased concentration of CO2 in the atmosphere. How does one explain this discrepancy? CO2 certainly has a warming affect but how much? Might something else be going on that is even more powerful? Perhaps the correlation between solar activity and temperature found by Harvard scientists many moons ago has something to do with the earth’s heating and cooling.

  18. agent601 says:

    Squash that global warming guilt into a pin-head sized ball by getting 14 billion free carbon offsets:


  19. robj says:

    For the skeptics claiming we should wait to actuntil the waves are over Galveston because of bad data and bad science, proxy data is fraught with problems. But climate science has been focusing on that issue for the last 1o years, and the successful recovery of ice cores going back more than 100,000 years give much further confidence about atmospheric composition.

    Yes, warming goes in short-term and long-term cycles. Geologically, the last 50 years is quite unusual, just as the last year of stock market returns has been quite unusual. The explanatory principle (theory) linking greenhouse gases (CO2 and methane, principally) and the Milankovitch cycle as the main drivers of the glacial/interglacial cycles is not in dispute–save by the fringe who violate Occam’s razor in trying to dispute the relationship. Skepticism plays a useful role in driving science to overcome it with new data, but the skeptic position over the last 5-6 years of research is finding fewer and fewer places to hide and still come up with plausible explanations for why the last 150 years should not be explained primarily by greenhouse gas.

    Review the longterm correlation between CO2 and warming (going back millions of years), review the the changes geologically in greenhouse gas composition which usually change extremely gradually on a decadal or even century basis (warming can go up rapidly once a trigger point is reaches, as at the end of the last interglacial period when the North American ice dam gave way or North American cooling if the gulf stream convection breaks down), then review again the steep climb in CO2 going back to the Mauna Lai measurements in the 1950s and confirmed by icebubble results. CO2 is increasing over the last 150 years at a rate a thousand time the normal geologic increase, and this neatly overlays the Industrial Revolution.

    Those who say this is “just” a theory are using theory in the common sense (Rush Limbaugh or creationism), not the scientific sense of theory. Science is built upon theory, and currently there is no legitimate competing theory to explain the phenomena of the last 50 years. The opening of the Northwest Passage for the first time in European conquest of the New World is one example, although I wish we had the data for the Arctic during the Viking colonization, since that is the only possible comparable period in the last millenia.

    So we can hope for a short-term cooling cycle of 20-40 years to give us more breathing time to adjust, but those who base their policy on this are the ones who lay all their money on a number on the roulette table when they first walk in the casino door. Read the last two IPCC science reports and you’ll see–legitimate doubts remain but increasingly study results increasingly confirm greenhouse as the main driver of what we have been seeing, as the South American, North American, and Alpine glaciers go into rapid retreat and the coral reefs (going back a long, long, time) begin to disappear because of the two drivers of ocean heat and acidity. These are outliers that cannot be dismissed as a mere 30 year heat shift.

    For a blog on many of these issues by climate scientists, see realclimate.org It’s a very useful way also of following climate research studies as the data sets first come in or papers are published. Otherwise, read the technical summary to the most recent IPCC science report, which condenses it down into a manageable 40-50 pages.

  20. gnomic says:

    All of the national science academies say that the planet is getting warmer, than man is the cause, specifically the gases caused by burning fossil fuels, and that not doing something about it will result in dire consequences for humanity and most other species on the planet. Sure, they could ALL be wrong, but then we don’t know what’s is causing it and we are dead anyway. OR we can act now and see if things get better or at least stop getting worse.

    But hey, if we’ve learned anything in this financial crisis, its lets ignore the smart people and take our lumps. Because its better to be rich and dead than rich and alive.

  21. DavidB says:

    A few points:

    1. First off, unless we call it climate change the crowd will appear divided and we’ll lose both people and thus the push.
    2. Climate change has been off the docket for at least a couple months. Once a theory is challenged with facts, we need to let it slide to the back of the agenda so that the media and government totalitarianizers don’t lose any more credibility than is absolutely necessary.
    3. Climate change is now in the same grouping as bird flu, SARS, AIDS, air borne AIDS, Bush’s aides, Bin Laden, Iraq, ebola virus and many of the other impending-crises-that-are-going-to-devastate-the-entire-world that are more than 6 months old. See point #2.
    4. The current public manipulating crisis is of course the financial crisis. Please don’t confuse the public and get them to be thinking about something else, not even something they were thinking about 6 months ago. The current push, since you seem to have not read the latest memo, is trying to panic them into letting the banking system and big business loot the Treasury. Your full cooperation in this matter is appreciated and imperative.
    5. Please read and fill out the latest poll on what the next crisis will be. Selections are:
    a. Food riots in the third world
    b. revolution in either:
    iii. America
    iiii. The entire world
    c.World tire shortage crisis(sponsored and suggested by goodyear)
    d. World kiwi fruit crisis(we’re leaning towards this one as the most credible and believable)

    Please fill out the form and submit it as soon as possible. This financial crisis is quickly approaching its best before date and our reporters are running out of ideas

  22. this happened to be the QOTD:

    If you torture the data long enough, it will confess to anything. —Ronald Coase

    thought it apt..

  23. Kyle says:


    I couldn’t agree more. Imagine if we had spent all that AIG bailout money on wind power plants.