Climate Scientists 95 Percent Certain that Global Warming Is Man-Made

Reuters has gotten hold of a copy of the new report by the United Nations' Intergovernment Panel on Climate Change that aims to summarize the best scientific data with regard to the causes, effects, and trends of climate change. From Reuters:

Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities - chiefly the burning of fossil fuels - are the main cause of warming since the 1950s.

That is up from at least 90 percent in the last report in 2007, 66 percent in 2001, and just over 50 in 1995, steadily squeezing out the arguments by a small minority of scientists that natural variations in the climate might be to blame.

That shifts the debate onto the extent of temperature rises and the likely impacts, from manageable to catastrophic....

The report will flag a high risk that global temperatures will increase this century by more than that level, and will say that evidence of rising sea levels is now "unequivocal".

Projected sea level rise by 2100 has been increased from 18 to 59 centimeters in the last report to 29 t0 82 centimeters (11.4 inches to 32.3 inches). The report also apparently backs off on the claim that warming has already made hurricanes worse. The new IPCC report will evidently try to explain why global average temperatures have been essentially flat for the past decade:

An IPCC draft says there is "medium confidence" that the slowing of the rise is "due in roughly equal measure" to natural variations in the weather and to other factors affecting energy reaching the Earth's surface.

Scientists believe causes could include: greater-than-expected quantities of ash from volcanoes, which dims sunlight; a decline in heat from the sun during a current 11-year solar cycle; more heat being absorbed by the deep oceans; or the possibility that the climate may be less sensitive than expected to a build-up of carbon dioxide. (emphasis added) 

It will be very interesting to see how the new report handles the recent studies that suggest that climate sensitivity - conventionally defined as to how much warming can be expected from a doubling of carbon dioxide concentrations in the atmosphere - may be significantly less than had been earlier maintained. If those new studies are correct, that means that catastrophic warming is less likely and that humanity would have more time to address whatever problems future warming might cause.

The new IPCC Working Group 1 report on the physical sciences will be officially released on September 27.

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.

  • Cliché Bandit||

    I remain unconvinced that warming is a "Problem"

  • Live Free or Diet||

    It certainly has not been clearly demonstrated. History certainly doesn't back the idea for temperatures seen during the Holocene.

  • Drake||

    How about the temperatures seen during the Middle Ages and the Roman Republic (both warmer than today)?

  • RightNut||

    Jesus was CRUXIFIED by the ROMANS, does warmer weather still sound like fun to you? How many more Jesuses have to be CRUXIFIED before you deniers wake up?!

  • Rob||

    Five, but I can't promise anything.

  • Tejicano||

    We could throw a Juan or a Rafael in there too couldn't we?

  • Pro Libertate||

    How does confidence increase when the data seems to have become less, not more, reliable? Is this a rhetorical question on my part?

  • Cliché Bandit||

    If a kid asks where rain comes from, I think a cute thing to tell him is "God is crying." And if he asks why God is crying, another cute thing to tell him is "Probably because of something you did."
  • BiMonSciFiCon||

    Speaking of volcanoes, if you ever drop your keys into a river of molten lava, let 'em go, because man, they're gone.

  • RightNut||

    How many times have you dropped your keys into a river of molten lava?

  • gaijin||

    if you ever drop your keys into a river of molten lava, let 'em go

    But what if they are precious?

  • Killazontherun||

    That quote caught on with a lot of parents in the 80s and the poor kids who soaked it up also became more susceptible to the nonsense spouted by their loser hippie teachers. I blame Jack Handy for the rise of this new apocalyptic death cult infesting the nation with bad policy.

    DAMN YOU, FUNNY MAN! DAMN YOU!

  • paranoid android||

    My favorite was always (paraphrased):

    "A kid once asked me what happens when we die. I told him our bodies go into the ground and get eaten up by worms, and he ran off crying. I probably should have told him the truth, that God sends most of us to hell to be tortured for all eternity, but I didn't want to upset him."

  • Live Free or Diet||

    If I answer "yes" should I have answered at at?

  • Pro Libertate||

    I don't know. I think it depends whether the second question was also rhetorical.

  • Live Free or Diet||

    Due to that uncertainty, I am even more certain the answer is yes!

  • tarran||

    No it's not.

    The worse the actual real world evidence gets, the more loudly the people whose livelihood depends on the movement's success scream it's getting better.

    Donna Laframboise, did a pretty good job investigating the various people who form the body of writers and editors of the IPCC report, which she wrote up in The Delinquent Teenager Who Was Mistaken for the World's Top Climate Expert.

    The same laughable process is still at play. At this point the Earth could be sliding into an ice age, and the IPCC would still be blaming fossil fuels and mankind, and calling for more widespread energy poverty.

  • Pro Libertate||

    You have to wonder if the people who benefit financially from AGW alarmism won't try to take steps to actually warm the Earth.

  • Swiss Servator - past LTC(ret)||

    Set fire to Algore?

  • anon||

    I freaking wish.

  • fish||

    He's pretty fatty....it would look like you set fire to a pile of old tires. Are you comfortable with that?

  • anon||

    Kinda like smelling your own fart; you know it's gonna be bad, but you just gotta do it.

  • Smilin' Joe Fission||

    Look at who owns green energy companies and you will find who profits from global warming alarmism.

  • WTF||

    How does confidence increase when the data seems to have become less, not more, reliable?

    a) Consensus! The purge of the deniers is almost complete!
    b) FYTW.

  • ||

    c) But things are not as they teach us.
    d) FTWIHAIHTTS.

  • Calidissident||

    It seems odd to me that there was such a large increase since 2001, despite the fact that the warming trend has been stagnant since the late 90s

  • Rasilio||

    "Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities are the main cause of warming since the 1950s."

    Translation that every non scientist will miss (excluding a good chunk of climate scientists who will miss it as well) ...

    "It is likely that most but not all of the warming was the result of anthropogenic causes, however we havn't got the slightest friggin clue whether most means 51%, 75%, or 99%"

  • ant1sthenes||

    It's worse than that. If they have 9 other possible natural factors plus all man-made factors in a tenth category, it just needs to be the largest of the ten.

    It could be 11% and still be the "main" factor, depending one what they mean by that.

  • Westmiller||

    Exactly correct. The "confidence level" is also a statistical trick. It has nothing to do with scientific evidence (all of the climate models have failed), but the number of paid IPCC personnel in one small category of "attribution" who endorse the finding.

  • WTF||

    How does confidence increase when the data seems to have become less, not more, reliable?

    a) The purge of the Deniers is almost complete! Consensus!
    b) FYTW

  • WTF||

    SQUIRRELS!!

  • T||

    Wow, they get blamed for everything. Is there a global squirrel cabal secretly in charge of mankind's destiny?

    I would think a global cabal you could defeat with enough time and .22 ammo wouldn't be that effective.

    Wait, there's a shortage of .22 right now...

  • Swiss Servator - past LTC(ret)||

    Wait, there's a shortage of .22 right now...

    Yes, yes there is.

    /Squirrel

  • Chaucer||

  • Redmanfms||

    This movie looks fucking awesome.

  • Not an Economist||

    Hey, there the ones really responsible for global climate change.

  • ||

    Climate Scientists 95 Percent Certain that Global Warming Is Man-Made

    "Rent-seekers Look to Maintain Employment and Funding"

  • Brett L||

    Goddammit. These guys have more or less destroyed everything the anti-alchemists built from the end of the 15th century until the middle of the 20th. Say, Francis Bacon to Richard Feynman.

  • tarran||

    No... they have not.

    They have seized control of institutions and organizations.

    But science is a process, and any individual or organization can take up that process at any time.

    Organizations are temporary.

  • Brett L||

    Fair point. I think I said a similar thing to someone else. Its just that goddamn Johnson and the war.

  • John||

    But in doing that they are destroying people's faith in science. Once people start to think science is just a political tool, it is going to be very hard to get them to believe in any science no matter how compelling.

    See the vaccine hysteria for example.

  • Westmiller||

    Why would people believe that IPCC "science is just a political tool"?

    Just because that's the explicit *purpose* of the IPCC, in it's official charter statement: to provide "useful" advice to politicians?

    http://www.ipcc.ch/organization/organization.shtml

  • The Late P Brooks||

    Blah blah fucking blah.

  • Brett L||

    More evidence of AGW. Its a baby orca crying you evil denialist fucks. Why do you want to make Gaia nad bsby killer whales cry?

  • ||

    The cult gets more culty. Who could have imagined?

  • Swiss Servator - past LTC(ret)||

    Comet Hale-Bopp, here they come!

  • BakedPenguin||

    The top of the Heaven's Gate logo looked just like the Green Bay Packers logo.

    Coincidence?

  • Ted S.||

    Hale-Bopp
    dit dit doo wop
    dit dit dit dit duh
    Hale-Bopp
    dit dit doo wop
    Oh ooh oh oh

  • T||

    When confronted by unbelievers, double down on proclaiming the inerrancy of your faith. It's always the way, ain't it?

  • Paul.||

    Zzz...

  • Diomasach||

    So if burning fossil fuels is the main cause of warming since 1950, what about the 20,000 some odd years before that? Come on folks, those glaciers went somewhere! And it's got to be somebody's fault!

  • John||

    What does "90% certain" even mean? How can you be 90% certain of something? Sure, if you are talking about events in the future, speaking in percentages makes sense. But they are talking about interpreting current and past events. Unlike the future, the past doesn't deal in percentages. It either happened one way or it didn't. Saying you are 90% certain that this or that happened in the past is just another way of saying you don't know.

  • Palin's Buttplug||

    Romney was 90% certain to lose to Obama back in October - according to Nate Silver.

    That is what it means.

  • John||

    http://www.youtube.com/watch?v=RnYUFKFs5As

    BUSHPIG!!!

    No one even feels sorry for you anymore shreek.

  • cw||

    Uh, yeah, you made no point whatsoever.

  • Palin's Buttplug||

    Only losers deny overwhelming probability.

  • John||

    Probably only applies to the future not the past. The past either happened one way or it didn't. You have a such a low IQ. But make up for it by having poor reading comprehension.

    It is funny to think there are probably four or five equally stupid leftists who run this sock puppet account. And each one out does the other for stupidity. How do you people feed yourselves or remember to breath.

  • Palin's Buttplug||

    Before the election you dismissed Sliver as a partisan hack while predicting an easy Romney win.

    You are the sucker at the table, John. And you are too stupid to realize it even after repeated warnings.

  • RightNut||

    Silver is a partisan hack.

  • cw||

    I am 90% certain you were a monkey in a past life. Only losers deny overwhelming probability.

  • ||

    Overwhelming probability? According to a group of guys who have a huge incentive to keep saying "climate is changing"? What a shock. Anyways, it's not surprising you're already championing this crap as fact when it hasn't even been published or made it through peer review.

  • ||

    Trying to be condescending when you are utterly ignorant of how confidence intervals work is just kinda sad. I mean, it's embarrassing to watch, but you're so stupid you aren't even embarrassed by it.

  • cw||

    It's curious how they are certain that anthropogenic activity caused a worldwide warming trend over the past 60 years, yet natural variations are responsible for a warming hiatus in the last 15, when anthropogenic activity has grown tremendously.

  • John||

    That is a good question. More importantly, the entire statement is nonsense. To accurately estimate your chances of being correct, you have to understand the phenomena you are talking about. And if you understand the phenomena, you know what happened and thus are 100% right. It is the past, not the future. So when you say I am whatever percent certain, you are just saying you don't know what happened.

  • ||

    “We are 95% certain humans are responsible for the increase the past 60 years.”
    “But what about the lack of increase the past 15 years?”
    “We are 50% certain that nature is responsible for that.”
    “But there’s more human influence now than 60 years ago.”
    “We are 100% certain that you are an idiot for asking those questions.”

  • ant1sthenes||

    Someone's never heard of confidence intervals. Or, you know, science, which tends to deal with heavily with statistics, probability, significance, and that sort of thing.

  • John||

    We are not talking about predictions we are talking about describing a past event.

  • ||

    The analysis is still probabilistic in nature though. Even a backward-looking analysis can examine unknown contributors to a given outcome using probability.

  • albo||

    "Fixing" global warming is the environmentalist-statis wet dream. There's probably global warming porn out there somewhere.

    Personally, we should try to reverse global warming, because it could be keeping the next ice age at bay, and mile-high glaciers sitting on top of Wisconsin will destroy millions of Packers fans.

  • Anonymous Coward||

    mile-high glaciers sitting on top of Wisconsin will destroy millions of Packers fans.

    How is that a problem?

  • BiMonSciFiCon||

    In the event that this were to occur, the Bears would still find a way to lose to the Pack.

    Go Pack Go.

  • Coeus||

    There's probably global warming porn out there somewhere.

    There is (watch til the end).

  • Anonymous Coward||

    it is at least 95 percent likely that human activities - chiefly the burning of fossil fuels - are the main cause of warming since the 1950s.

    And prior to that?

  • John||

    And how do you know you are 95% certain? You can't. Either you know what happened or you don't. There is no guess or probability.

  • ||

    Confidence intervals don't indicate certainty. They indicate likelihood that a given data range will contain a certain parameter. I didn't link out to the study, but in that context, I would guess they're analyzing peer-revied global warming - err, sorry, climate change - studies, and the increasing confidence interval just indicates a higher likelihood that those studies will conclude anthropogenic causes of warming. IOW, it may just mean they are more in lock-step. It says nothing about the actual validity of the conclusions.

  • anon||

    And prior to that?

    You assume they care about evidence that might contradict the claims of the apocalypse being nigh.

    They do not.

  • cw||

    The whole political-economy ramifications of this are just like with practically everything the government does:

    Adopt more interventionist policies to stem a perceived problem; if problem abates, credit the interventions; if problem continues, double down on interventions and blame non-interventionists.

    With this formula, and coupled with an uncritical media, you can accomplish anything in the minds of the masses!

  • anon||

    Goddamnit Ron, quit lighting the Retard Beacon. John can't help but to respond to them.

  • John||

    It is mean of me to take advantage of their illness.

  • Smilin' Joe Fission||

    This is the result of global warming alarmism in politics (Warning this is for Ontario, Canada).

    “The province’s claim that 50,000 jobs will be created by the GEA [Green Energy Act] was unsupported by any formal analysis and the province has since admitted both that the vast majority of any GEA-related jobs will be temporary, and that the 50,000 figure does not account for offsetting permanent job losses due to electricity price increases under the GEA,” the report concluded. “Consequently, the claim has no basis in fact.”

    Taken together, the green energy subsidies will add some $18-billion to Ontario power rates, more than 30 times the $585-million cost of the [gas-fired] power plant cancellations. But it gets worse because, as in the case of the cancelled power plants, Ontarians still won’t get the power supply they’re paying for, or at least not much of it.
  • John||

    We have people in positions of power who believe things that are total superstition but is called "science". It really is like electing faith healers to run national health policy.

  • Smilin' Joe Fission||

    It is disgusting. Ontario already has one of the cleanest, both in respect to CO2 and pollution, electricity grids since 50%+ of the electricity is from nuclear power. The rest is mainly from hydro and nat gas.

    These wind farms and solar farms are getting massive subsidies to set up. It really is a transfer of wealth from the poor to the rich who own these green energy companies.

  • Scruffy Nerfherder||

    Scammers gonna' scam

  • anon||

    Dude, Guam tipping over isn't a joke.

  • Scruffy Nerfherder||

    Congress in a nutshell, right there.

  • Scruffy Nerfherder||

    I wouldn't expect anything less from Canuckistan

  • Smilin' Joe Fission||

    Well at least the premier, Dalton McGuinty, was essentially fired over it. Even though he should b getting jail time for the absolute corruption that has occurred over the cancelled natural gas plants and crazy crony green-energy idea.

  • Scruffy Nerfherder||

    He had good intentions Joe. That's all that counts.

  • JW||

    UN apparatchiks discover a problem that only UN apparatchiks can solve. News at 11.

  • ||

    The entire theory is nonsensical.

    CO2 went from 250 ppm to 400 ppm. That makes the total amount of CO2 in the atmosphere 0.04% (Venus is 96.5% for comparison). So two times nothing is what again? NOTHING!

    So to make the theory fit, they claim there are negative feedback loops. IOW, an increase in CO2 will warm the world slightly and that in turn will release more CO2 from the ocean floor and the permafrost...

    That implies negative static stability. A system cannot exist in nature with negative static stability. The second you deviate (a volcano) the entire system diverges.

    The entire theory is dubious at best, and there is obviously some force in place preventing preventing the predicted results. CO2 levels are still increasing. Where's the heat?

  • John||

    There isn't any. And since they can't reliably recreate temperature records going back before 1979, they have no idea if the "warming" that has occurred is in any way out of the ordinary.

    The entire thing is complete nonsense. And shame on anyone who believes it.

  • cw||

    Tony would argue the heat's sunk into the deep ocean.

  • ||

    Heat and Mass Transfer, how does it work?

  • Not an Economist||

    That is the leading theory by climate scientist and there is some evidence to back that up (whether the evidence is accurate is another story). They are still trying to figure out how the heat got into the deep ocean and how it might come back.

    Just remember, the science is settled.

  • ||

    One would think, as a scientist, how it got there without warming the atmosphere might be the first question you'd ask yourself.

  • ||

    " an increase in CO2 will warm the world slightly and that in turn will release more CO2 from the ocean floor and the permafrost..."

    Which is hilarious because the exact opposite is true: The increase in C02 in the very short term MIGHT cause a slight uptick in temperature, but it will increase evaporation of surface water, which will sequester all of that atmospheric CO2 back to the sea floor, leading to a decrease in temperature.

  • Auric Demonocles||

    Negative feedback loops would keep the system stable. You are talking about *positive* feedback loops.

    /controls engineer

  • ||

    I stand corrected.

    Give me a break, it's been 25 years since my stability and control class.

  • R C Dean||

    My amateur understanding is that there is a limit to how much heat CO2 can trap. There are diminishing returns that hit a ceiling.

    That's why the models all have to posit feedback loops that mysteriously get triggered when the temperature hits levels that it has hit repeatedly in the past without ever triggering those feedback loops.

  • Goldwin Smith||

    So they admit that temperatures have been flat? How many scientists predicted that? What sort of new hypotheses have they made to fix the flaws of the previous ones?

    And how can it be the "warmest year on record" if temperatures are flat?

  • John||

    Every year is the new warmest year on record. It is sort of like we have always been at war with Oceania.

  • ||

    Oh, they aren't lying. It is hotter. But the increase is insignificant and is not even close to what the climate models predict.

    You'll notice you never hear them compare the increases with what was predicted. Just...the hottest year on record.

  • wef||

    I recommend looking at Luboš Motl's take on this. To summarize:

    1. First of all, the figure 95% isn't really calculated in any way. It's literally pulled out of the air. [i.e., bullshit rhetorical, flourish for drawing attention of the jaundiced masses.] 2. Even if the figure 95% were credible, it's just painfully low. [Given confirmation bias and the sexy-results filter of contemporary science kabuki.] And 3. Even if the figure 95% were credible, calculated, and replaced by a much higher figure, the statement we have "learned" is completely unspectacular, pretty much inconsequential, and unworthy of spending another dollar. [WTF does "main cause" mean? A half, a third, a quarter, a fifth, etc., of a half a degree increase over the course of 60 years?]

    http://motls.blogspot.com/2013.....-ipcc.html

  • John||

    I am 95% sure this is the main cause of what happened. That statement means nothing. It is not even wrong. It can't be right or wrong because it doesn't make any sort of assertion that can be judged.

  • Raston Bot||

    It will be very interesting to see how the new report handles the recent studies that suggest that climate sensitivity - conventionally defined as to how much warming can be expected from a doubling of carbon dioxide concentrations in the atmosphere - may be significantly less than had been earlier maintained.

    *** SPOILER ALERT ***

    it won't.

  • John||

    Ron can't get over his love of the top men on this issue. No matter the evidence, he just can't come out and say it is all crap.

  • Brandon||

    How do they arrive at the 95% number? I would like to see the supporting data and the calculations.

  • OldMexican||

    Reuters has gotten hold of a copy of the new report by the United Nations' Intergovernment Panel on Climate Change


    Once we start with an absurdity, you know you're in for being bamboozled.

    An IPCC draft says there is "medium confidence" that the slowing of the rise is "due in roughly equal measure" to natural variations in the weather and to other factors affecting energy reaching the Earth's surface.


    I had assurances from them and others that Climate Change(TM) was a totally, unequivocally artificial (i.e. man-made) phenomenon. Either it is or it isn't. If climate is sensible to natural variables, then any supposed increase in CO2 due to human activity becomes nothing more than another variable and thus not as compelling as a sales pitch when the time comes to open the purses of the rich dupes and corrupt politicians.

    or the possibility that the climate may be less sensitive than expected to a build-up of carbon dioxide


    We may be witnessing the slow but steady process of back-peddaling from all the extraordinary claims and scares with which they bombarded us for two decades. It is certainly fun to watch, especially because these dolts still cling to the notion that there is no such thing as the Internet and massive data storage, where their claptrap can be revisited until the sun becomes a white dwarf.

  • John||

    At some point they will find a new excuse to oppose progress and move on from AGW. As I said above, it makes no logical sense to ascribe a percentage to the likelyhood of your understanding of a past event being correct. If you don't understand the event, you have no idea how likely your hypothesis is. And if you do understand it, you know whether it happened that way or not with 100% certainty.

    They don't know and the data doesn't match their predictions. But they can't admit that so they pulled this percentage out of their ass so they wouldn't have to admit they don't know.

  • Harvard||

    I've been away. Have they solved that nasty cow flatus thingey yet??

    Beano in grist perhaps??

  • Tejicano||

    I find it pretty much hilarious that the left will ferret out any evidence of some entity making a PROFIT and ascribe all manner of ill-intentions which that graft inspired. But when it comes to AGW they see no possibility that the people whose entire living depends on the certainty of man-made global warming could be influenced by that fact to push the results in their own favor. In addition, most of those people would at best be marginally employed without the AGW crusade.

    OTOH, just about every DENIER has no financial skin in the game which makes sense that they would be more impartial.

    This scenario alone would be enough to give me pause to believe anything said by the AGW pushers.

  • Mr Whipple||

    ...United Nations' Intergovernment Panel...

    You may as well just say it came from the Federal Reserve or the IMF, or Jamie Dimon's personal secretary or a cartel of alternative energy companies.

  • ||

    Koch brothers! Big Oil! False consciousness!

  • Canman||

    Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities - chiefly the burning of fossil fuels - are the main cause of warming since the 1950s.

    Is this hw they compute their error margin?

    http://climateaudit.org/2008/0.....rpshooter/

  • robert-j||

    Makayla. you think Don`s story is terrific... on sunday I bought Jaguar XJ when I got my cheque for $7323 this last month and just a little over 10-k last month. with-out a doubt this is the most comfortable work I have ever had. I started this eight months/ago and immediately startad bringin in at least $82.. per-hour. I follow the details here, http://www.jobs76.com

  • Anthony Ricigliano||

    Interesting new findings on Global Warming.

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