11 February 2010

Weather is not Climate

Let's see if I can make this simple.

What happens in the weather this week or next tells us absolutely nothing about the role of humans in influencing the climate system. It is unjustifiable to claim that a cold snap or heavy snow disproves or even casts doubts predictions of long-term climate change. It is equally unjustifiable to say that a cold snap or heavy snow in any way offers empirical support for predictions of long-term climate change. This goes for all weather events.

Further, it is professionally irresponsible for scientists to claim that some observed weather is "consistent with" long-term predictions of climate change. Any and all weather fits this criteria. Similarly, any and all weather is also "consistent with" failing predictions of long-term climate change. The "consistent with" canard is purposely misleading.

Knowledge of climate requires long-term records -- on the time scale of a decade and longer. Don't look to the weather to learn about climate, unless you have a long time to watch. Using the weather to score cheap political points in the climate debate appears to be a tactical area of agreement among those who otherwise disagree about climate change.


  1. Lots o' Consistent With here:


  2. For the more mathematically inclined, I wrote up a little demo of this distinction using a forced version of Lorenz's 1963 system. It also talks about how the hand-waving about solving initial value problems as opposed to boundary value problems is not really very useful (or technically accurate) for giving people insight into these differences.

  3. In fewer words:
    Correlation should make you curious not convinced.

  4. Greetings from Baltimore where we are enjoying 3 feet of weather that's not climate. This type of weather (although not this much) had been predicted by meteorologists as a consequence of a mild El-Nino in a cool phase of the PDO similar to what happened in the late '70's. I fully agree with the concept that this prooves nothing about the climate but if one subsribes to the premise that the oceans currents and their temperature cycles drive climate, then you really need a minimum of one cycle and preferably 2 cycles to even begin to get a handle on the climate trends. For the PDO that's a minimum of 60 years and ideally 120 years of observations. Instead we always reference back to the late '70's, when the global warming started in earnest (which was at the end of the last cool phase of the PDO) and track to end of the positive phase of the PDO around the turn of the century then draw linear plots off into stratosphere. So you really cannot look at one exceptional event except to observe that this seems to happen with a certain regularity. Perhaps when the weather is not climate discussion starts, we might use it as an opportunity to ditch the 30 year (half a PDO cycle view) and get folks to focus on 60 or 120 year views to really begin to put these events in context.

  5. Yes - I know a snow storm is not evidence that AGW is false (especially with the UAH global temps at an El Nino peak).

    But is it so much fun to watch the alarmists squirm because for years they relied on the public's natural tendency to equate weather with climate to sell the 'AGW is a crisis' meme.

  6. We had to suffer 'the 2003 European heatwave is proof of global warming.' Then it was floods are proof of 'global warming.' Now we see various factions of climate alarmists claiming less snow and more snow is consistent with 'global warming' theory.

    It's just the weather, non of which is inconsistent with or beyond the bounds of Holocene natural variability.

    I've heard it said that some people think that they control the weather and climate by attempting to manipulate atmospheric CO2. It takes all sorts, I suppose!

  7. Profession irresponsibility has defined the entire public relations effort of the IPCC and associated groups. Media reporting for more than a decade has consisted entirely of scientists behaving irresponsibly and making claims that they know are not supported.

    What does that tell you about the science they are doing?

  8. What's humorous is to watch the learned, enlightened scholars claim that this cold and snowy weather is proof of global warming... especially since Rio is having a heat wave.

  9. Weather isn't climate but is really cheap politics.

    My gut feel is the minimum time frame to look at climate direction is closer to 50 years than 10.

    Maybe even 100 years.

  10. Raven, the public opinions on AGW is indeed driven by science, politics, media and weather. Different weather are favourable for different advocates. Lately I have noticed that many sceptics in Sweden are using the cold weather as an explicit argument that AGW are most likely false. Thus, these sceptics are explicitly ignorant and proud of being ignorant. This is sad, since I hoped, and still hope, that sceptics can help to nuance and reframe the debate in constructive ways. Overall, I am not very impressed by the sceptics slack scientific standards and the way that they so often confuse sound critique of science with their own political views, usually a mix of conservative values and neoliberal politics.

    Also the comments by some sceptics on Pielkes blog gives a rather mixed feeling. Demand for "objectivity" and "sound" science on the one hand, and biased views on what this "objectivity" and "soundness" is on the other hand. Their is a strong bias in this demand. Sceptics should take it seriously, if sceptics wants to be taken seriously on their own terms. For me, I believe that the fundament of the discussion is wrong, objectivity and impartiality is not possible, the whole problem is staged wrong before the debate has even started.

    Yes, AGW is a cricis meme, for some it is a threat to the so called american lifestyle (driving big cars, eating lots of food, live in big houses, consumption, consumtion, comsumption ... SELF-INTEREST!) whereas for others it is a threat for survival (food, water, starvation... yes, also self-interest).

    WE should all take the science AND the politics seriously. Pielke is doing a good job on this.

  11. Weather is not climate, but climate is weather.
    Until the credibility of AGW promoters completely collapses, they will continue to reverse the relationship.
    Most skeptics look at these events- and point out that they are well within the range of normal variation in a highly variable system. In other words, the point is that the weather we have been experiencing is proof of nothing but normal.
    However, the AGW social movement has sensitized people to see *proof* of the climate apocalypse at every turn. AGW opinion leaders take full advantage of this sensitivity.

  12. "What happens in the weather this week or next tells us absolutely nothing about the role of humans in influencing the climate system."

    Hmmm...have you discussed this theory with Kevin Trenberth? ;-)


    "Kevin E. Trenberth, chief of the climate-analysis branch of the National Center for Atmospheric Research in Colorado, said, 'There are very good reasons to believe that the current U.S. heat wave is at least partly caused by global warming.'"

  13. The wagons are being circled, though.


  14. Ah, you may be absolutely correct to point out that weather is not climate.Alas, as we all have been subject to every conceivable weather event being related to the so-called 'global warming', can we not even enjoy the thought of the reverse being related to 'global cooling' ;-)

  15. This is a very timely post. I watched the first story on the Keith Olbermann show last night and it was on the GOP (and commenters like Rush L) using the current blizzard blowing through DC as proof that there is no AGW. He pointed out the obvious that weather is not climate. But then he went a step farther and used the current weather as proof that AGW is real, as AGW is supposed to bring severe weather events! So Mr. Olbermann went from making a legitimate point to being as scientifically unsound as those he was criticizing. In some ways, what he did was much worse. No one would accuse Rush or GOP lawmakers of relying on science to make their points. But Olbermann is making a categorical statement to blast someone based on science, and he got the science wrong.

    One can blame skeptics and deniers for the lack of confidence in AGW (or Global Climate Change), but the damage being done is by those making really broad and definitive statements that goes far beyond what the science can say or support.

    But it's not only non-scientist who fall victim to the "weather as climate" trap. One of the amazing elements in your recent posts on how your research (and the literature) on trends in disaster lost was being misused (mischaracterized, misrepresented), were those that wanted to change your findings based on the Atlantic hurricane seasons of 2004, 2005. Basically they wanted to overturn a long-term (multi-decadal) trend based on the most recent 2 years. It made me wonder what part of "weather is not climate" don't they understand, unless it is only when something happens that doesn't fit with their hypothesis. I'd expect principles to be stable across a range of outcomes, not in politics, but at the very least, in science.

  16. Andreas:
    There are lots of possible natural events that if they happen will create huge difficulties for large portions of mankind. There is a need to size these various possibilities in terms of their effects, their likelihoods and the feasibility of doing something about them where the cost of doing it is of the same order of magnitude as the effects of doing nothing. Answering these questions is very difficult.
    You are undoubtedly correct in saying that some skeptics are not particularly objective in their criticisms. Alas I fear that many pro-CAGWers are equally non-objective in their alarmism. One hallmark of the latter is the use of hyperbole in framing criticisms. This normally provokes skeptics - both those who are scientific and those who are largely political.
    If you want to understand the skeptics viewpoint, sans your hyperbolic self-interest nonsense, I urge you to carefully read two classics, along with our host's Honest Broker: Bjorn Lomborg's Skeptical Environmentalist (apparently the IPCC authors did not which explains a number of the errors) and the late Aaron Wildavsky's But Is It True?

  17. Roger, you are missing something here: events like these prove that weather that effects people occurs no matter what, and it also proves that people like RFK Jr who make overstated claims about weather phenomenon are wrong.


    Do you really think that a simple real world illustration of the overstatement of claims is not important?

    It is also worth noting that it is reasonable to point out that events like this should become rarer and there isn't as yet indication that such a tendency has occurred.

  18. bernie, sorry for the hyperbole.
    All sides use hyperbole and gets provoked, its part of the problem with the climate debate.
    I am provoked by the fact that 1) neither believers nor sceptics are following their own standards 2) that the standards are vicious since they results in what Pielke calls "stealh issue advocacy".

    I think we agree on 1. I will try to explain 2:
    First, self-interest is all but nonsense. It is the number one explanation to climate politics. Self-interest is also important to what we percieve as sound, neutral and even objective. What is percieved as neutral and sound in the US context is much different from the European context. The "objectivists" may think that they are objective, but they are not (this is equally true of believers and sceptics). I am provoked that so many believers and sceptics does not acknowledge their own subjectivity and respect their subjectivity as a legitimate and important aspect of the climate issue.

    I understand Lomborgs basic claim, not as a claim on physical changes in nature, but on how we value nature and society and whether society is improving or not. This regards 1) how to frame environmental issues 2) how to value, what is valuable, etc. But the fundament tells us that we must discuss the physical aspects but not values, so the debate is predestined to be vicious. We must separate the debate on:
    1: physical-biological (empirical)
    2: social-economic-political (empirical)
    3: appropriate frames (value-laden)
    4: how to value and respond (value)
    as the same time as we are aware of that they are intertwined in empirical reality.

  19. Roger,
    What about the cost of a cold snap versus a warm snap. Say climate change would mean less cold snaps and more warm snaps (as I am told), what would this mean for cost for society, I have the feeling it would be net beneficial.

    greetings from a snowy netherlands, where we have almost run out of roadsalt.

  20. According to the BBC

    Scotland records coldest (ever) winter

    By combining the temperatures of January and December it showed they were the coldest since 1914 - the year data started being logged.


    Is that weather or climate ?

    The only thing to do was fell a tree in the garden which is over 100 years old, and dust down the paleoclimatology skills. It turns out that it is actually five degrees warmer than a century ago.

    Conclusion :- it's definitely weather, and the BBC are being funded by Exxon Mobile as we all suspected.

  21. From Jonathan Rose in the Christian Science Monitor on the Global Warming and the Psychology of Weather:

    "The Earth is warming, which is changing weather patterns and often causing localized weather volatility as opposed to localized warming. Extreme storms, droughts, intense rains, unusual amounts of snow or lack of snow are all signs of global warming. People know the weather is getting less predictable. They call it “weird weather.”"

    This is terrible stuff.

  22. Hans,
    In the U.S., more people die in heat waves than in cold snaps. Although I am sure (as Roger would point out) this depends on climate and socio-economic conditions and is probably not true in, say, Finland.

  23. TSL, its commonly accepted that cold kills far more people than heat, even in the United States. Study with references:


    "Cold-related deaths are far more numerous than heat-related deaths in the United States, Europe, and almost all countries outside the tropics, and almost all of them are due to common illnesses that are increased by cold."

    Sure, Wikipedia may tell you that heat waves are the most lethal type of weather phenomenon, and its probably correct. But more people still die in winter than in summer.

  24. #19 Andreas

    "What is percieved as neutral and sound in the US context is much different from the European context."

    Yes...the US has 238 Billion tonnes of coal sitting in the ground, compared to the EU's 29 Billion Tonnes.

    If the US didn't have the Coal our discussions would more closely mirror EU discussions.

  25. I want a clear definition of climate change. If it's an average of weather over the long term and all analyses show nothing much has changed over the last hundred years then clearly there is no climate change happening at all by that definition.

    If however it's only to be defined as a global temperature anomaly then it needs to be clearly called global warming not climate change and it needs pointed out that despite the overall warming there wasn't much change in long-term weather, ie climate, so fears that it will in the future are groundless pessimism.

    The problem is the conflation - warming has happened -> warming is climate -> climate has changed -> climate means long term weather -> more freak weather is happening. Yet this progression is just not backed up with any facts. Though that doesn't stop several publicity-hungry scientists from inventing that it has - even going so far as to outright lie that the models predict it will happen.

    But it gets worse because if we expect that warmth brings wilder weather then surely cold must bring the opposite. Yet they predicted in the 70's that cold would bring exactly the same wild weather as is now predicted for warmth. The only way out of this logic conundrum is to realize that some things might get worse, others might get better but since there is no sign that 0.6 degrees of warming over a century has caused anything abnormal then there is no need for such blind panic. That is the reality behind all the pseudo-scientific arm-waving.

  26. Hello Roger,

    Just a heads up, you used an image from Getty images at top.

    From personal experience let me warn you that they have a team of people constantly scouring the web looking for licensing violations. On one website a couple of years ago I sued a couple of thumbnail sized images, not even knowing they originated from Getty.

    I got a nasty letter from their legal dept. demanding $2000.00 for what they claimed was a licensing violation (even though it seemed fair use).

    The matter was resolved, but I will never ever use Getty images for anything again.

    You are welcome to use this image from my website:


    which looks similar and is in fact public domain since funded by the US Senate.

  27. 23-And yet heat related mortality is on the decline, even as urbanization and general atmospheric warming occurs.

    It seems that people are just...resilient. Who would have thought that a species that emerged from the equatorial grasslands to dominate virtually every continent and every environment on earth could adapt to climate change!

  28. Its hot. Its cold. It rains. It snows.

    Its Global Cooling. Then Global Warming. Then it Climate Change.

    Its hard cold science facts. Then its not so factual science. Then its completely void of fact and science.

    It’s a-political. Then it’s a little political. Then its all about politics.

    Its not about money. Then it’s a little about money. Then its all about money.

    The whole environmentalist movement is about saving the earth. Then its about saving the earth with some political power. Then it’s a series of socialist organizations hijacking the environmentalist movement.

    Global + Baloney = Globaloney.

  29. This also brings us back to the salient policy point around all this.

    No AGW, mild AGW, significant AGW, whatever. The largest costs to society will come through weather events that would have occurred under any of those scenarios.

    For policy purposes, this should be treated no differently to earthquake or tsunami risk. Adaptation and planning, not change mitigation.

  30. Congratulations. You have managed to forget the entire point of monitoring climate. You have tried to turn it into some mathematical construct that means the climate is the long term average of the weather. That is about as useful as telling someone that the average temperature in Minneapolis is about 40°F. That is an entirely useless fact. Climate is just as much about measuring the extremes of the weather and that knowledge is much more important.

    If one is going to invest in a citrus plantation in Florida, the one climate fact one wants to know is the probability of a hard frost in the next twenty years. Not the average temperature, nor the average monthly temperature, but the probability of a single extreme event. One might also want to know the probability of a hurricane. The average wind speed is just kind of useless.

    Record breaking snowfalls along the east coast are extreme weather events that are part of the climate and are much more important that knowing the average temperature. People want to know if they should invest in air conditioning for heat waves and snowblowers for the winter.

    The extremes of the weather are just as much part of the climate as the average and knowledge of the extremes are more important than the averages. A single record breaking storm is important even if it has insignificant effect on the average.

  31. Gary P. -Do you agree that these variables from the Wikipedia definition (below) are the correct ones to measure climate? Are you saying that the variances are just as important as the means?
    Are you suggesting that the variances around the means have increased due to AGW?
    If that is true, do we have data to compare the variances for the last 50-100 years?
    From Wikipedia
    "Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and numerous other meteorological elements in a given region over long periods of time. Climate can be contrasted to weather, which is the present condition of these same elements over periods up to two weeks."

  32. Like throwing snake eyes and saying, "See. The dice are loaded."

  33. Gary P
    Now if someone could predict these extreme events that would indeed be highly useful. However just saying that it'll be a mild winter due to global warming then when we get a cold winter they then also attribute that to global warming is actually worse than saying they just don't know.

    And if you have been misled by some irresponsible journalism into thinking that computer models can predict these things then be aware that they can't even get the average local temperatures correct, never mind extreme events in those locales.

    Study by all means but don't pretend to know things that you absolutely don't!