Rorschach blot
People see the most interesting things in the world around them. Some people see Stephen Hawking's initials in the universe's microwave background radiation. Others seek patterns in the clouds or lines on a palm. People are hard-wired to look for meaning in patterns. Not all patterns have meaning, but many do. Geologists, for instance, pay a lot of (legitimate) attention to patterns in ancient sediments: these patterns, called primary structures, give information about current flow direction, exposure to air, and the presence of living organisms. Others can orient us to which way was "up" when the sediments were deposited. Cross-bedding, mudcracks, and bioturbation are some examples of patterns with meaning. Seeing a dog's face in a rock exposure is an example of a pattern that lacks meaning, as surely as if one saw the same dog's face in the meaningless blobs of ink in a Rorschach test.
Lately, I've been thinking about the human predisposition for perceiving meaning in patterns.
The week before last, I gave a presentation at a local middle school about climate change. Before my talk, one of the teachers came up to me to ask if I thought that global warming could have triggered the earthquake. He whispered conspiratorially, "There have been a lot of earthquakes lately!" I said no, because (1) I couldn't think of a plausible mechanism for that to work in Haiti* and (2) there are perfectly good tectonic reasons for the Haiti earthquake, and (3) there haven't been more earthquakes lately than usual, at least not in any significant way.
As I type these words, the first snowflakes are falling in the second major snowstorm to hit Washington, DC, in less than a week. The first, dubbed Snowmageddon or the Snowpocalypse, dumped more than 18 inches of snow on the capital city. The city does not respond well to that amount of snow: schools shut, the government closed, and there were insane panicked runs on groceries at the area's stores. The new storm, dubbed Snoverkill, adds insult to injury with another 6 to 16 inches predicted. The schools I teach for, NOVA and GMU, have both been closed since last Friday. The way it's looking now, I'm not going to be working again until this coming Friday -- a full week lost due to the white stuff.
What's interesting to me is how people react to the snow. I mean this on two levels: one is the obvious fact that both the culture and infrastructure of Washington, DC, are quite poorly equipped to deal with a couple feet of snow. However, that's not as interesting as the way the snow serves as a reflection on people's mental states. Some people look at the two big snowstorms coming back to back and say, "Where's global warming now?" Others look at the same two storms, with fear that this is the new paradigm like The Day After Tomorrow, and say, "See what climate change hath wrought?" The thing is, they are both wrong.
Weather is not climate, even when two weather events occur in the same week. Tamino calculates that you need about 14 years of temperature data to tease out the long-term trend. Nine years isn't enough, and one week isn't enough. Yet people notice the "clumping" of these data: "two storms in one week! That's a pattern! It must therefore be significant! If it's significant, it's therefore reflective of a common cause, and that common cause is the one I have already decided to be true. Therefore these two storms are evidence of global warming / global cooling**" (depending on who you're listening to).
The thing is, data are clumpy. There is going to be noise in the data. When it comes to snowstorms, the noise is the weather. The noise is superimposed upon a longer-term trend. That trend is the climate. Likewise with earthquakes: no one expects earthquakes to occur with a periodicity regular enough to set to music. Earthquakes of a certain size have a certain probability of occuring in a given period of time, but there's no guarantee that one will occur. If you calculate the average number of earthquakes during a given period of time, and then compare any period of time to that average, your comparison time period will either have more earthquakes than the average or less earthquakes than the average. Ditto for snowstorms: some winters will be more snowy. Some winters will be less snowy.
There are exceptions, such as earthquakes triggered by other earthquakes, or a common cause. The recent earthquake storm at Yellowstone is sufficiently constrained in time and space to suggest that it indeed is a group related by a common cause (though it does not show a magmatic signature, another case of people seeing what they want in the data). Haiti's aftershocks play the same game, though not every earthquake that occurs in Haiti is necessarily connected to the big shock.
Anyhow, this stuff has been on my mind this week. The world is one big Rorschach blot, and humans see what they want in it. We are psychologically all too likely to jump from pattern recognition (noticing clumps in data) to conclusions (often pre-determined), without taking the time to really analyze whether there is in fact a trend present, and if that trend is significant, and if there is a logical causal mechanism to explain that trend.
We are a species that seeks meaning: some augur the future from tea leaves, while others engage in science and reason. Some methods of gaining access to meaning are themselves meaningful. Others are meaningless. Both surround us.
Stay warm out there.
________________________________________
* Though potentially up in Greenland it could work due to glacial melting causing unloading on the crust, changing the stress field that's keeping a fault locked in place.
** It's probably also worth pointing out that snow does not equal temperature. It's precipitation. People are visually susceptible to the sight of snow: it registers more than numbers.
Lately, I've been thinking about the human predisposition for perceiving meaning in patterns.
The week before last, I gave a presentation at a local middle school about climate change. Before my talk, one of the teachers came up to me to ask if I thought that global warming could have triggered the earthquake. He whispered conspiratorially, "There have been a lot of earthquakes lately!" I said no, because (1) I couldn't think of a plausible mechanism for that to work in Haiti* and (2) there are perfectly good tectonic reasons for the Haiti earthquake, and (3) there haven't been more earthquakes lately than usual, at least not in any significant way.
As I type these words, the first snowflakes are falling in the second major snowstorm to hit Washington, DC, in less than a week. The first, dubbed Snowmageddon or the Snowpocalypse, dumped more than 18 inches of snow on the capital city. The city does not respond well to that amount of snow: schools shut, the government closed, and there were insane panicked runs on groceries at the area's stores. The new storm, dubbed Snoverkill, adds insult to injury with another 6 to 16 inches predicted. The schools I teach for, NOVA and GMU, have both been closed since last Friday. The way it's looking now, I'm not going to be working again until this coming Friday -- a full week lost due to the white stuff.
What's interesting to me is how people react to the snow. I mean this on two levels: one is the obvious fact that both the culture and infrastructure of Washington, DC, are quite poorly equipped to deal with a couple feet of snow. However, that's not as interesting as the way the snow serves as a reflection on people's mental states. Some people look at the two big snowstorms coming back to back and say, "Where's global warming now?" Others look at the same two storms, with fear that this is the new paradigm like The Day After Tomorrow, and say, "See what climate change hath wrought?" The thing is, they are both wrong.
Weather is not climate, even when two weather events occur in the same week. Tamino calculates that you need about 14 years of temperature data to tease out the long-term trend. Nine years isn't enough, and one week isn't enough. Yet people notice the "clumping" of these data: "two storms in one week! That's a pattern! It must therefore be significant! If it's significant, it's therefore reflective of a common cause, and that common cause is the one I have already decided to be true. Therefore these two storms are evidence of global warming / global cooling**" (depending on who you're listening to).
The thing is, data are clumpy. There is going to be noise in the data. When it comes to snowstorms, the noise is the weather. The noise is superimposed upon a longer-term trend. That trend is the climate. Likewise with earthquakes: no one expects earthquakes to occur with a periodicity regular enough to set to music. Earthquakes of a certain size have a certain probability of occuring in a given period of time, but there's no guarantee that one will occur. If you calculate the average number of earthquakes during a given period of time, and then compare any period of time to that average, your comparison time period will either have more earthquakes than the average or less earthquakes than the average. Ditto for snowstorms: some winters will be more snowy. Some winters will be less snowy.
There are exceptions, such as earthquakes triggered by other earthquakes, or a common cause. The recent earthquake storm at Yellowstone is sufficiently constrained in time and space to suggest that it indeed is a group related by a common cause (though it does not show a magmatic signature, another case of people seeing what they want in the data). Haiti's aftershocks play the same game, though not every earthquake that occurs in Haiti is necessarily connected to the big shock.
Anyhow, this stuff has been on my mind this week. The world is one big Rorschach blot, and humans see what they want in it. We are psychologically all too likely to jump from pattern recognition (noticing clumps in data) to conclusions (often pre-determined), without taking the time to really analyze whether there is in fact a trend present, and if that trend is significant, and if there is a logical causal mechanism to explain that trend.
We are a species that seeks meaning: some augur the future from tea leaves, while others engage in science and reason. Some methods of gaining access to meaning are themselves meaningful. Others are meaningless. Both surround us.
Stay warm out there.
________________________________________
* Though potentially up in Greenland it could work due to glacial melting causing unloading on the crust, changing the stress field that's keeping a fault locked in place.
** It's probably also worth pointing out that snow does not equal temperature. It's precipitation. People are visually susceptible to the sight of snow: it registers more than numbers.
Labels: analogies, climate change, dc, movies, nova, primary structures, science and society, snow
8 Comments:
A truly outstanding post. Well said!
I'm distracted by the name "Snoverkill." (Sounds like the name of a river in upstate New York or something.)
Very nice post. Reminds me of reading the classic paper from Zeller (1964) called 'Cycles and Psychology' that I read in an advanced strat class years ago. In the paper they summarize an experiment where they gave people synthetic strat columns made from random numbers in the phone book and people, of course, interpreted cyclic patterns.
It might make a fun exercise for a class.
You can find that paper here.
While we, here, haven't received the amount of snow from these storms as others, both hit us. And, an AGW denier tried to draw a correlation...
So, rather than try and convince someone that has made up their mind, I retorted with the same fallacy: "I think that the folks in Vancouver would beg to differ".
That shut him up!
Yesterday, when me and my girlfriend were waiting at the railway station for the train to arrive, we listened to a couple of people exclaiming: "global warming can't be true, look at all these amounts of snow! And it's so cold! Surely, the thing on the news, that IPCC scientists made mistakes in the report, it must be true." Too bad I don't have their e-mail address to send them the link to this blog :)
Thanks Callan for putting things in proper perspective.
I heard the same old denial stuff yesterday where I was working. Since they are my customers I generally do not respond to their criticisms, but it is ironic how the same fallacious denial critcisms and conclusions from ancedotal evidence(regarding the weather) seem to spread around...i.e. that the scientists blame everything anomalus on GW, that they lie or it is a socialist,UN sponsered one world government conspiracy; these AGW believers are just trying to get rich off these scare tactics and take away our cars, ad infinitum etc.
It is depressing though that so many people listen to those in the media who either want to foster denial for power or political purposes or do not understand the science of climate change and give out wrong information.
There are almost 7 billion people on this planet and growing using enormous amounts of energy and resources;producing massive amounts of waste, something unprecedented in the human history. To think that we have only a neglible effect on the life sustaining biology of this planet and that we can continue complacently doing the same short-sighted things for the next 50 years that we have done for the last 150 years is the biggest delusion of all.
My comment to AGW has to do with balance and equilibrium. If we (aka, Humans) are stressing the system by putting way too much CO2 in the atmosphere then we should be seeing responses like exceedingly rapid tree growth (in both numbers and size)and increases in coral reefs and shelly organisms.
I still find it hard to believe that low atmosphere emissions of CO2 has a global impact. Now, a volcano spewing CO2 30,000ft into the upper atmosphere is another story.
Jack Siegel:
Warmer waters do not facilitate coral growth in historical coral ranges, especially when those same waters are dosed with extra CO2. Coral bleaching is triggered by temperatures rising above those at which corals are comfortable. When oceans absorb CO2 from the atmosphere, it lowers the pH of the water (making it harder for corals to precipitate CaCO3).
As for trees, I don't know as much about them, except to say that there are many factors which control plant growth: temperature, moisture, soil nutrients, sunlight energy, and CO2 in the atosphere. It is unambigous that CO2 levels are rising. If the plants aren't responding the way you had expected, I suggest you take it up with the plants.
Your second comment about lower-atmosphere vs. higher-atmosphere CO2 emissions appears to be mixing up SO2 with CO2. Sulfur dioxide is not the same chemical compound as carbon dioxide. When sulfur aerosols get injected into the high atmosphere by exceptional volcanic eruptions, it has an immediate and significant effect on the weather the following year. It cools the climate. The classic example to cite is the eruption of Tambora in 1815, and the ensuing "year without a summer" in 1816. Note that this is not CO2, but SO2 -- and no one really talks about what elevation CO2 is emitted at. I haven't heard anything to suggest that the elevation of CO2 emissions are in any way significant.
So, unless I am reading your comments wrong, you have some fundamental misunderstandings of the natural facts relevant to the issue being discussed. Hopefully my explanations above will set your understanding straight -- these are objective facts, not ideological viewpoints.
I respect that you find it "hard to believe" that our emissions of CO2 have an impact on the planet. Probably that has something to do with the fact that CO2 is an invisible gas which you cannot directly observe with your senses. Do you doubt that humanity has an effect on erosion rates? ...What about changes to biodiversity?
...Changes to forest cover? Like CO2 increases, erosion increase, biodiversity decrease and forest cover decrease are all measurable quantities. The good news is that you don't have to believe anything. You can measure these variables. The data can be gathered. No belief is required for a dispassionate analysis of these systems. Of course, if you opt for "belief" over data, that's your choice.
Though you voice no specific ideology in your comments (only ignorance of the facts), I cannot help but wonder whether your ignorance stems from ideological motivations (resisting investigating the science underlying climate change because of a fear of being convinced to the opposite ideological viewpoint), or whether it stems from sheer intellectual laziness.
I guess I don't really need to know the ultimate source of your illiteracy of the climate system, though. I thank you for your question, so that I can debunk those myths here. A public-interest science blog needs to address issues like this directly, and I'm grateful for the opportunity.
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