Humans Are the Certain Cause of Climate Change

So says the new IPCC report on the science of global warming.

Today, the United Nations' Intergovernmental Panel on Climate Change (IPCC) published a new Summary for Policymakers (SPM), cataloguing what is known about the physical basis for man-made global warming. The IPCC states that there is now 95 percent certainty that more than half of the warming over the past 60 years can be attributed to human activity. Since 1951, global average temperature has increased by approximately 0.6°C to 0.7°C. The dominant cause for increasing average global temperatures, the panel finds, is the rising level of carbon dioxide in the atmosphere emitted by burning fossil fuels. In addition, "Each of the last three decades has been successively warmer at the Earth's surface than any preceding decade since 1850. In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years."

Beyond the certainty that humanity is causing the planet to warm more than it otherwise would, what does the SPM have to tell us? One crucial issue is climate sensitivity, conventionally defined as the amount of warming that doubling carbon dioxide in the atmosphere would eventually produce. In its 2007 report, the IPCC estimated that climate sensitivity was between 2 degrees Celsius and 4.5 degrees Celsius, with the best estimate being 3 degrees Celsius. The new report finds that "climate sensitivity is likely in the range 1.5°C to 4.5°C (high confidence), extremely unlikely less than 1°C (high confidence), and very unlikely greater than 6°C (medium confidence)." In IPCC parlance, likely means that the authors believe that there is more than a 66 percent chance that they’ve gotten the right estimate for climate sensitivity, whereas extremely unlikely means that they think there is less than 5 percent chance that they are wrong.

However, several recent studies have reported that climate sensitivity could be somewhat lower than the SPM suggests. For example, an article in the May Nature Geoscience concluded that the "most likely value of equilibrium climate sensitivity based on the energy budget of the most recent decade is 2.0 °C, with a 5–95% confidence interval of 1.2–3.9 °C." This is a whole degree lower than the best estimate calculated by the IPCC in 2007. Interestingly, the new SPM, unlike its predecessor reports, provides no best estimate of climate sensitivity. In any case, lower climate sensitivity would mean that future warming will be slower, giving humanity more time to adapt and to decarbonize its energy production technologies.

A big issue bedeviling the IPCC is how to take into account the 15-year "hiatus" in which average global temperatures have not significantly increased. Such a long pause was not predicted by any of the climate computer models relied upon by the IPCC. The new SPM deals with this awkward situation basically by waving it away, asserting that a 15-year pause is too short a time from which to draw any conclusions regarding future warming trends.

"Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends," the SPM states. Nevertheless, the report asserts this: "The long-term climate model simulations show a trend in global-mean surface temperature from 1951 to 2012 that agrees with the observed trend (very high confidence)." What is the observed long-term trend? An increase of 0.12 °C per decade. To illustrate how sensitive temperature trends are starting and ending dates, the SPM notes that for 15-year periods starting in 1995, 1996, and 1997 the global average temperature trends are 0.13, 0.14, and 0.07 °C per decade, respectively.

So are the models relied upon by the IPCC really all that good at simulating trends in global average temperature? An August 28 article in the journal Nature Climate Change suggests that they are not. The Canadian climate researchers pointed out that while global average temperatures rose over the past 20 years at a rate of 0.14 ± 0.06 °C per decade, 37 of the models relied upon by the IPCC simulated an average rise of 0.30 ± 0.02 °C per decade. "The observed rate of warming given above is less than half of this simulated rate, and only a few simulations provide warming trends within the range of observational uncertainty," conclude the authors. It gets worse. For the period after 1998 until 2013, the researchers note, "The observed trend of 0.05 ± 0.08 °C per decade is more than four times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade." Given this disparity, how can the IPCC have "very high confidence" that model projections agree with observed temperature trends when they clearly don’t?

The new SPM elsewhere does acknowledge with "medium confidence" that internal decadal variability is the cause of much of the difference between observations and the simulations. The SPM adds that the models cannot be expected to simulate the timing of the sort of natural climate variability that has produced the current 15-year pause. "If the IPCC attributes to the pause to natural internal variability, then this begs the question as to what extent the warming between 1975 and 2000 can also be explained by natural internal variability," the Georgia Tech climatologist Judith Curry observes. "Not to mention raising questions about the confidence that we should place in the IPCC's projections of future climate change."

Another significant issue addressed by the SPM is projected sea level rise. As warming seas expand and as icecaps and mountain glaciers melt in Greenland and Antarctica, the extra water drains into the ocean, increasing sea level. In its 2007 report, the IPCC crudely estimated that sea level could rise by 2090 by between 7 to 24 inches. For context, sea level rose about 8 inches between 1870 and 2004. Taking into account various scenarios about how much future warming the world might expect, the new SPM has boosted projected sea level rise from a low of 10 to a high of 38 inches by 2100. If warming turns out to be lower than the models project, then so too will future sea level rise.

"Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions," declared Thomas Stocker, the co-chair of the physical science group, in a press release. The Obama administration is all on board: In a statement hailing the new report, Secretary of State John Kerry warned, "Boil down the IPCC report and here’s what you find: Climate change is real, it's happening now, human beings are the cause of this transformation, and only action by human beings can save the world from its worst impacts." The action will resume when the 19th Conference of the Parties to the United Nations Framework Convention on Climate Change convenes in Warsaw this November. Stay tuned.

Editor's Note: We invite comments and request that they be civil and on-topic. We do not moderate or assume any responsibility for comments, which are owned by the readers who post them. Comments do not represent the views of Reason.com or Reason Foundation. We reserve the right to delete any comment for any reason at any time. Report abuses.

  • Brett L||

    1983–2012 was likely the warmest 30-year period of the last 1400 years

    Huh. Why would we pick a 30 year span? That's weird.

  • Pro Libertate||

    Can that be right? There was a warm period in the Middle Ages where they were growing grapes in Great Britain. Or was that Grape Britain then?

  • Brett L||

    Certainly, agriculture in Greenland was around later than 600 CE. How long is hard to tell, because we're still finding stuff under glacial melt.

  • Square||

    Are you sure about that? Everything I've read suggests it was considerably colder in Europe in the middle ages. Where did you hear about the grapes?

  • ||

    I just googled "wine making in medieval britain" and the first link was to RealClimate from 2006. The author tries to argue that there are too many variables in viticulture for it to be a good proxy.

    I laughed for two minutes straight at his complete lack of self-awareness.

  • Square||

    I think I read the same article, but the salient point was that however you read the evidence, there are far more vineyards in Britain now than there ever have been before.

    The article is definitely coming from a position, though, of "how can I make this evidence fit my theory?" He pretty much says that since we can't really make very good statements about general climate trends, the prevailing model of human-caused warming should remain unchallenged.

  • TheZeitgeist||

    Viticulture in Britain predates the Middle Ages, to the best of my knowledge it was Romans who introduced it - and were also the ones to pack it in after the climate cooled.

  • Tony||

    That wasn't a global phenomenon.

  • Bill||

    But Sandy was, right? And some heavy rain in Colorado is global, and the Arctic ice melting a bit more in some summers, they are all global, right?

  • Broseph of Invention||

    I remember 1257-1286 being pretty warm.

  • Adam330||

    Look, 15 years is clearly a "short records [that is] very sensitive to the beginning and end dates and do[es not in general reflect long-term climate trends," but 30 years is double that! Clearly it's long enough. Even though both 15 years and 30 years are a blink of an eye in context of the earth's climate.

  • Tony||

    Are you confused about something in these findings?

  • NotAnotherSkippy||

    Yes, he's confused about the fact that the IPCC thinks the warming of the first have of the 30 year period somehow trumps the complete lack of warming of the second half of the 30 year period. Or, as we like to call it in the biz: religion.

  • ||

    I'm confused how an increase of .01degreesC per year is anything more than a rounding error.

  • Super Hans||

    Indeed. Look at the accuracy of thermometers, particularly when you rely on century old instrumental records.
    And frankly, I'm not sure if modern satellite measurements are accurate to 0.01C.

  • mtrueman||

    I've never heard of a time span that wasn't weird. What's your point?

  • Diomasach||

    For the same reason they pick "the last 1400 years" - Because it helps them sell their point.
    That's why every single pro-AGW climate model starts 1400 years ago - coincidentally the coldest part of the Little Ice Age.
    Because if they showed you the ENTIRE climate history going back hundreds of thousands of years you would see a completely unremarkable cyclical warming trend.

  • tarran||

    From Two Minutes to Midnight by Steven McIntyre

    Conclusion

    No credence should be given to IPCC’s last-minute attribution of the discrepancy to “natural variability”. IPCC’s ad hoc analysis purporting to support this claim does not stand up to the light of day.
    Gavin Schmidt excused IPCC’s failure to squarely address the discrepancy between models and observations saying that it was “just ridiculous” that IPCC be “up to date”:
    The idea that IPCC needs to be up to date on what was written last week is just ridiculous.”
    But the problem not arise “last week”. While the issue has only recently become acute, it has become acute because of accumulating failure during the AR5 assessment process, including errors and misrepresentations by IPCC in the assessments sent out for external review; the almost total failure of the academic climate community to address the discrepancy; gatekeeping by fellow-traveling journal editors that suppressed criticism of the defects in the limited academic literature on the topic.
    Whatever the ultimate scientific explanation for the pause and its implications for the apparent discrepancy between models and observations, policy-makers must be feeling very letdown by the failure of IPCC and its contributing academic community to adequately address an issue that is critical to them and to the public.
  • tarran||

    That academics (e.g. Fyfe et al here; von Storch here) have finally begun to touch on the problem, but only after the IPCC deadline must surely add to their frustration. Von Storch neatly summarized the problem and calmly (as he does well) set it out as an important topic of ongoing research, but any investor in the climate research process must surely wonder why this wasn’t brought up six years ago in the scoping of the AR5 report.
    One cannot help but wonder whether WG1 Chair Thomas Stocker might not have served the policy community better by spending more time ensuring that the discrepancy between models and observations was properly addressed in the IPCC draft reports, perhaps even highlighting research problems while there was time in the process, than figuring out how IPCC could evade FOI requests.
  • Pro Libertate||

    If it's half, what's causing the other half of the warming? Assuming there even is a warming trend anymore.

  • Paul.||

    Planes flying around for environmental conferences in Rio.

  • Pro Libertate||

    Oh, I see. The one half is caused by brutish deniers, burning coal for entertainment, and the other half is caused by the enlightened faithful, burning fossil fuels under protest.

  • Paul.||

    They'll use their half the way they want to, you can use your half the way you want to.

  • Wind Rider||

    They'll use their half the way they want to, you can use your half the way you want to. they tell you to.

    FIFY

  • Tony||

    At least half.

  • Sevo||

    Yes, and a claimed less than 100% certainty.

  • Snark Plissken||

    Dear Editor,

    Ronald Bailey should stick to what he's bad at, writing science fiction books.

    Sincerely,
    Abraham Simpson

    --

    Almost actual letter I saw someone link to on The Tweeter.

  • Ron Bailey||

    SP: I wonder where the writer got his facts? A quick google search would have told him that I have never written science fiction - writing fiction is way too hard. I am however an avid reader of sci-fi.

  • Paul.||

    You don't have to tell me twice.

  • Juice||

    writing good fiction is way too hard

  • NotAnotherSkippy||

    Just ask the IPCC.

  • phandaal||

    ZING

  • Scarecrow Repair||

    Well sure, that's the point, he's saying your science articles ARE bad science fiction.

  • Ron Bailey||

    SP: I wonder where the writer got his facts? A quick google search would have told him that I have never written science fiction - writing fiction is way too hard. I am however an avid reader of sci-fi.

  • Cliché Bandit||

    HA SQUIRRELS EVEN AFFECT YOU!!!!

    awesome

  • ||

    Those are killer squirrels, not even afraid of the staff.

  • ||

    Since 1951, global average temperature has increased by approximately 0.6°C to 0.7°C.

    That's roughly .1°C per decade or .01°C per year. That's not a trend, that's a rounding error.

    Never mind the fact that we can't possibly know what causes such a "trend".

  • mtrueman||

    "That's not a trend, that's a rounding error."

    Your position is that we should ignore scientists and their fancy measuring equipment and rely on our own common sense. I find this unpersuasive.

    "we can't possibly know what causes such a "trend"."

    The article doesn't mention this, strangely enough, but CO2 has been known as a heat trapping greenhouse gas for more than 150 years. We humans emit some 20 billion tonnes of it into the atmosphere each year.

  • ||

    Your position is that we should ignore scientists and their fancy measuring equipment and rely on our own common sense. I find this unpersuasive.

    Google "calculating error". you will see that when calculating error you cannot use decimal places that appear when calculating average. You may also take note that there does not exist a device nor will there ever be a device that can measure the whole earth's temperature to .01th of a degree.

    Rounding errors are not common sense they are in fact science.

  • mtrueman||

    The .01 degree per year was Designate's contribution. The article stated that warming of .6 or .7 had taken place since 1951.

  • Sevo||

    "The .01 degree per year was Designate's contribution. The article stated that warming of .6 or .7 had taken place since 1951."

    .01/year X 60 years = 0.6. What is your point?

  • mtrueman||

    A figure showing the daily increase over 60 years would be even smaller than .01.

  • AlexInCT||

    After the revelations of abuse and outright lying, to achieve a political goal of all things, why does anyone think that anything that comes out of that IPCC circle jerk should be given any sort of credible thought? We should all be telling these hucksters to FOAD already. Let them go find another global crisis to hock their expansion of government powers and wealth confiscation schemes. Maybe they can pretend that we have an ice age because man has gotten too fat coming next.

  • mtrueman||

    There are some 15,000 US troops stationed in Kuwait to 'secure the supply of oil.' A global crisis waiting to happen, made possible by a grant from your local federal government.

    I think the scientific community is the least of our worries. They have a culture of skepticism, and are relatively open and above board. They may not tell us things we want to hear and that understandably leads to the anti-intellectual attitude on display here.

    Understand this, though. 'They' don't need scientists to bilk you and rob you.

  • VG Zaytsev||

    Sure they do. There's always a backlash when the thievery gets too blatant.

  • mtrueman||

    Government grants to climate studies must be about as unblatant a form of robbery as ever perpetrated, and just as tiny considering all the other forms of robbery going on.

    Maybe i'm naive but i still have respect for science and scientists and to see them slagged off as hucksters and parasites in the pages of Reason, without anyone stepping in to defend them, well that angers me.

  • Sevo||

    "Maybe i'm naive"

    Or stupid.
    It's not the total amount that drives corruption, it's the amount available to the individual tempted by corruption.
    Did you know that and you're hoping no one figures it out? Or are you stupid enough not to know that?

  • mtrueman||

    "it's the amount available to the individual tempted by corruption"

    Does this tempted individual have a name you care to share with us? I should point out also there is a world of difference between being tempted by corruption and corruption itself.

  • itsnotmeitsyou||

    I love how 15 years of data showing no warming is "too short a time from which to draw any conclusions regarding future warming trends."

    However, the data from the previous 15-20 years is absolute proof positive that we're all gonna die.

    derpity derp derp

  • Bill||

    Hansen made his first claims in 1988 so it was less than 10 years of warming.

    From 1988 to 2002 is 14 years.

  • Brett L||

    My favorite: For the period after 1998 until 2013, the researchers note, "The observed trend of 0.05 ± 0.08 °C per decade is more than four times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade."

    Wait, what? The observed trend is smaller than the error? That's not a trend, that's noise.

  • Brett L||

    Oh, wait. That's not the SPM.

  • tarran||

    Actually, one can pull a signal out of lossy, noisy data.

    In this case, though, the signal doesn't mean shit: the CAGW theory is utterly falsified by its failure to predict the behavior of the climate based on the current inputs.

    Perhaps humans could be significantly warming the planet. But, if they are it ain't the C02 triggering increased evaporation that in turn traps more hear raising temperatures theory that the IPCC is peddling.

    And their response to the people pointing out the increasing pile of data falsifying their hypotheses is getting pretty formulaic.

  • Brett L||

    Actually, one can pull a signal out of lossy, noisy data.

    The IPCC must not be able to or they wouldn't be taking about certainties of a line that drifts in one direction away from the trend. I'd like to see the fit on that line, though. I'll be surprised if its better than 0.85. I wonder if I still have access to Web of Science...

  • NotAnotherSkippy||

    Yes, you can pull a signal out of noisy data using accepted and proven statistical methods. But you're assuming that there is a signal... The not rejected null hypothesis is that there is not.

  • phandaal||

    This is what gets me. When confronted by a model that gives bad data, other people pursuing different types of scientific inquiry are vehement about throwing the model out the window or changing it to match observed data.

    Not so with these so-called scientists in the climate change field, though. It's just "Tax Everything RIGHT NOW."

  • mtrueman||

    Modelling the earth's climate must be one of the most hair-raisingly difficult intellectual challenges man has ever faced. Hyperbole? I'm not so sure. I'm certain however you are underestimating the difficulty of the task and the complexity of the climate.

  • VG Zaytsev||

    No, the hysterics are. First y claiming that global average temperature is meaningful in any way and secondly by claiming that a single variable controls that global average temperature.

  • mtrueman||

    You shouldn't really concern yourself over what hysterics say. Average global temperature is meaningful in some sense, though clearly a tricky concept.

    On the second point, i've come across self proclaimed skeptics who reject the whole global warming theory on the grounds that temperature doesn't increase lockstep with CO2 levels. To varying degrees, we all fall victim to what our common sense tells us should be the case.

  • CatoTheElder||

    How can an intellectually honest modeler be confident his 0.21 °C per decade model result is accurate within ± 0.03 °C per decade if measurements of the actual trend are only accurate within ± 0.08 °C per decade?

    Seriously, how does this make any sense?

  • Juice||

    They injected the uncertainty with consensus.

  • Fist of Etiquette||

    In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years.

    They can't know it. They can't credibly guess it. Absolute bullshit statement.

  • Pro Libertate||

    What's odd is I don't think it's true even based on what we do know. I know there was a warm period during the Middle Ages. Like warmer than now warm.

    I've seen some climatologist statements that the mean temperature then was lower than today, but that sounds fishy, knowing how dramatically warmer places like Britain and Greenland were then. Warmer than anytime in modern history.

  • Paul.||

    Most of that Medieval Warm Period was caused by an overabundance of Morris Dancing. So, still man-made.

  • johnl||

    1400 was during the little ice age. The Greenland colony was failing and British grape growing was history by then. That's why they chose that date for comparison.

  • Adam330||

    They say "the last 1400 years," which would put us back to 600AD.

  • Pro Libertate||

    Yes, that's right. That takes us back to before the Medieval Warming Period.

  • johnl||

    OK then they are just obviously wrong.

  • mtrueman||

    "knowing how dramatically warmer places like Britain and Greenland"

    Were there places that were cooler in that period? This is a global phenomenon, after all.

  • Paul.||

    They can't know it. They can't credibly guess it. Absolute bullshit statement.

    If they can tell me that shark migration patterns in the Atlantic changed because of racism, they can calculate how the temperatures in 1983-2012 (aka the early to late Madonna era) relates to the prior 1400 goals.

  • Paul.||

    *goals* Ha. I'm typing while a co-worker is having a meeting asking the consultant what his ultimate 'goal' is.

    That's incredibly funny, to me.

    Years... years is what I meant.

  • Cliché Bandit||

    you have demonstrated the veracity of a yes tree. In typing. Nice.

  • Sevo||

    "A big issue bedeviling the IPCC is how to take into account the 15-year "hiatus" in which average global temperatures have not significantly increased"

    If I'm not wrong, this is 15 years *and counting*, which means it's a lack of increase since 1998, which shows no sign of changing. That's a very different animal compared to 'a 15 year hiatus'.
    Waving that away while requesting massive changes in the economy is dishonest in the extreme.

  • lovewedleton||

    my best friend's aunt makes $67 an hour on the laptop. She has been fired from work for 5 months but last month her pay check was $13328 just working on the laptop for a few hours. try here

    ------------
    http://www.works23.com

  • Your Pal, Dan||

    Climate change denial derp

  • ThatSkepticGuy||

    Phil Plait has a bad habit of letting his politics and ego override his skepticism a la Chris Mooney.

  • Juice||

    Is he saying that the air heats the surface of the oceans and then that warmer water sinks to displace and warm the cold water at the bottom of the ocean?

  • Bill||

    Yes. Without ever showing up as an increase in temperature/heat in the upper 700 meters of the ocean which is a smaller volume so should increase in temp. more than deep layer. Stealth heat.

  • Sevo||

    Is there any evidence of the heat in the deep water? And "evidence" presumes some baseline against which to measure.

  • NotAnotherSkippy||

    A little bit, but the record of temps at the 2000m level is less than a decade so there's really no history there. Plus, as Bill pointed out the heat magically materializes in the deep layers and skips the intermediate layers. I guess I'm going to have to give back all of those A's in heat transfer and thermodynamics because that doesn't make any physical sense.

  • Coeus||

    The theory is that increasing temps have increased the natural transport mechanisms which already exist. So it's happening because of a blending of the top layer and the bottom. The colder water from the bottom is coming up and counteracting the increase of temps from AGW in the upper level, while the lower continues to warm. Not saying they're correct, but the mechanism they've postulated makes sense.

  • NotAnotherSkippy||

    No, it really doesn't because either the heat is transported directly (conducted) in which case you'll see a temperature gradient in the whole water column (and which can't happen because net heat can't flow from colder layers to warmer layers), or mass and heat are transported together which still results in mixing of the layers and you'll still see a signature in the intermediate layer. Or unless nature has figured out how to tunnel on a macroscopic scale...

  • Paul.||

    And not that I’m looking forward to this, but eventually the ocean cycle will switch back to warming, and land surface temperatures will once again begin their inexorable climb.

    Remember kids, when the predictions don't come to fruition, call it a *pause*.

  • ||

    "If the IPCC attributes to the pause to natural internal variability, then this begs the question as to what extent the warming between 1975 and 2000 can also be explained by natural internal variability," the Georgia Tech climatologist Judith Curry observes. "Not to mention raising questions about the confidence that we should place in the IPCC's projections of future climate change."

    Not to mention raising questions about the confidence that we should place in the IPCC itself as a scientific and policy-recommending body.

    When will they finally acquire the shame needed to admit that they're just guessing and to express as a top-line fact that warming over the short to medium term is a net positive for humanity?

  • Bill||

    No.

  • ThatSkepticGuy||

    "The new SPM deals with this awkward situation basically by waving it away, asserting that a 15-year pause is too short a time from which to draw any conclusions regarding future warming trends."

    We're just gonna take these goalpostd, and set them down right over here.

  • Adam330||

    Better leave them on their wheels, because they're going to need moving again soon.

  • VernieCBurton||

    like Thomas answered I'm in shock that a stay at home mom able to profit $9426 in four weeks on the computer. browse around this web-site .,., Bay35.cℴm

  • CE||

    Their conclusion would be a little easier to defend if climate change had been minor or insignificant in the time before human society started flourishing. But climate change before us was by all scientific evidence much more severe.

    And "climate change" in recent years has been well within the normal year-to-year variation, so there might be no real trend at all.

  • Tony||

    But climate change before us was by all scientific evidence much more severe.

    But never so fast.

    Also, you don't know more than a collection of the world's experts in their field. Just thought I'd throw that possibility out there.

  • Ballz||

    "experts" my ass

  • Juice||

    But never so fast.

    Bullshit. Temperatures increased 5-8 C in about 40-50 years after the Younger Dryas.

    http://en.wikipedia.org/wiki/Y.....ate_period

  • Sevo||

    Tony|9.27.13 @ 5:31PM|#
    "But never so fast."

    Can you read? Check the data for the last 15 years and counting.

  • Sevo||

    Here, Tony, you don't even have to take hours looking for it:

    "A big issue bedeviling the IPCC is how to take into account the 15-year "hiatus" in which average global temperatures have not significantly increased"

    15years, no measurable increase. Got that?

  • Coeus||

    I'll bet he doesn't know more than the world's experts in phrenology, either.

  • ||

    But never so fast.

    The last ice age ended over a 50 year period. In other words you have mile high glaciers covering Canada then 50 years later you had what Canada and its climate is today...minus the trees of course.

    I live in eastern Washington. The floods that occurred because of this define the landscape of where i live.

    If you ever played with water and dirt as a kid, making little dams then breaking them, you can see all the rivets and swirls the water. That is what the Eastern half of Washington state looks like from space.

    You are talking out of your ass Tony.

  • ||

    you can see all the rivets and swirls the water makes in the dirt.

  • Ron||

    with CO2 @ 400 PPM it is a physical impossibility for it to have an effect on the atmosphere. Just do the math. I did and hope to publish the results soon.

  • ||

    I don't think you can wait for peer review. You better call a press conference immediately!

    In case you are not kidding, the principal mechanism of warming isn't CO2 per se: it is higher CO2 causing higher H2O.

    The little hole in the theory is that no one knows owhat the hell clouds do to the system. And H2O has a tendency to form... wait for it... clouds.

  • Greg F||

    The little hole in the theory is that no one knows what the hell clouds do to the system. And H2O has a tendency to form... wait for it... clouds.

    And low level clouds have a net cooling effect by reflecting more incoming solar radiation back out into space.

    What dim bulbs like Tony never understood was this water vapor feedback never had any supporting evidence. It was simply assumed to be true. In essence the 'consensus' was built on a belief.

  • Bill||

    Like all religions are.

  • Ron||

    It still won't matter, let me give you a hint all of the CO2 can only have an affect of 1/2500th and that is the maximum. Its all based on the math, very simple math at that, and all science is based on math.

  • Homple||

    Also sprach IPPC! Ex cathedra as well.

  • elizabethturner||

    ℳy classmate's step-sister ℳakes $82/h hourly on the internet. She has been out of a job for 6 ℳonths but last ℳonth her pay was $20983 just working on the internet for a few hours. Read ℳore on this site...

    http://www.Works23.com

  • ||

    Isn't this the same group that has been making dire predictions based on climate models that are over 90% INaccurate for years now?

  • Jayburd||

    HIDE THE DECLINE! HEY ROCKY, WATCH ME PULL A HOCKEY STICK OUT OF MY ASS!

  • Sevo||

    Aw, Bullwinkle, that trick never works!

  • James Anderson Merritt||

    THIS TIME FOR SURE! RUFFLE UP MY SLEEVE... PRESTO!

  • James Anderson Merritt||

    Since the whole global warming/climate change thing started up, we have found not only glitches in the models, but also significant new variables that we hadn't known about previously. Unless you know ALL the factors pertaining to a situation, and you have thoroughly investigated and eliminated (or controlled for) ALL but one, you cannot then turn around and blame the remaining factor (in this case, human activity) by default for the current state of the world. You at very least need to come up with a positive affirmation of that factor's influence on and importance to the phenomenon in question. So I hope the IPCC report explains, in detail, how it has arrived at "95% certainty" for its conclusions implicating humanity. Are scientists, for example, 95% certain that they won't find any more significant variables? Or do they believe that they have found variables that explain 95% of the climate change? Or that they have certainly found 95% of the variables they will ever find? If I don't find that kind of explanation in the report, I won't be persuaded by their assertion of "95% certainty."

  • Sevo||

    ..."you cannot then turn around and blame the remaining factor (in this case, human activity) by default for the current state of the world."...

    Not sure this is relevant.
    Let's say humans are the cause of 50%. So?
    It's not yet been shown to be a major problem, it's not yet been shown we have a plan to really address the issue.
    What we need is a way to deal with climate change (which is pretty much a constant regardless of the 'cause') in a way that benefits humanity.
    Gee, I have an idea! How about we use the price signals of the market to do so?

  • OBD2 Scanner||

    the co-chair of the physical science group, in a press release

GET REASON MAGAZINE

Get Reason's print or digital edition before it’s posted online

  • Progressive Puritans: From e-cigs to sex classifieds, the once transgressive left wants to criminalize fun.
  • Port Authoritarians: Chris Christie’s Bridgegate scandal
  • The Menace of Secret Government: Obama’s proposed intelligence reforms don’t safeguard civil liberties

SUBSCRIBE

advertisement