So I was chugging through my back issues of Nature, when I came across a review of Charles Seife’s must-skip book, Proofiness: The Dark Arts of Mathematical Deception. This paragraph derailed me:
Seife coins the term “proofiness” to refer to the misuse of numbers, deliberate or otherwise. He dubs the simplest quantitative sins “fruit-packing”. These include: “cherry-picking” the data, as he says Al Gore did when describing climate change in An Inconvenient Truth….
When in doubt, pick on Al Gore, because 1) the media loves a good Gore smear and 2) you don’t have to do your own mathematical homework because you can be sure the media won’t bother. You’re only telling them what they already believe, even if it isn’t true, which in this case, it isn’t.
I went online because I remembered seeing the Gore smear first in the NYT review of Proofiness, headlined, “Fibbing With Numbers“:
Seife is evenhanded about exposing the proofiness on both sides of the political aisle, though we all know who’s responsible for a vast majority of it: the other side.
He calls Al Gore to task for “cherry-picking” data about global warming. Although Seife doesn’t dispute that the warming is real and that human activities are to blame for a sizable portion of it, he chastises Gore for showing terrifying simulations of what would happen to Florida and Louisiana if sea levels were to rise by 20 feet, as could occur if the ice sheets in Greenland or West Antarctica were to melt almost completely. That possibility, while not out of the question, is generally considered an unlikely “very-worst-case” scenario, Seife writes.
I was going to debunk that at the time, but as is often the case with ClimateProgress, more urgent subjects came up. That’s why I have 1100 draft posts on Word Press. But I digress.
Once I saw the Nature review I realized that this unjustified smear had probably been picked up in most every review — and that meant potentially hundreds of thousands if not millions of people would see it, far more than would ever read Seife’s must-skip book. So it deserves debunking.
Now the question was, how could I find out what Seife had written without wasting any money on his inadequately-researched book? It wasn’t searchable on Amazon, but, his publisher, Penguin, was kind enough to post the relevant excerpt titled, “Phony Facts, Phony Figures.” I’ll quote it at length to capture the full context (italics and bold emphasis added):
There are many roads that lead to proofiness. Potemkin numbers create meaningless statistics. Disestimation distorts numbers, turning them into falsehoods by ignoring their inherent limitations. A third method, fruit-packing, is slightly different. In fruit-packing, it’s not the individual numbers that are false; it’s the presentation of the data that creates the proofiness.
Supermarkets select their fruit and arrange it just so and package it so that even mediocre produce looks delectable. Similarly, numerical fruit packers select data and arrange them and dress them up so that they look unassailable, even when they’re questionable. The most skilled fruit packers can make numbers, even solid ones, lie by placing them in the wrong context. It’s a surprisingly effective technique.
A particularly powerful weapon in the fruit packer’s arsenal is what’s known as cherry-picking. Cherry-picking is the careful selection of data, choosing those that support the argument you wish to make while underplaying or ignoring data that undermine it.
Since real-world numbers are fuzzy, answers to numerical questions aren’t always clear-cut. Measuring the same thing in different ways can give different answers; some of the numbers will be too high, some will be too low, and, with luck, others will be reasonably close to the right answer. The best way to figure out where the truth lies is to look at all of the data together, figuring out the advantages and disadvantages of each kind of measurement so that you get as close to the truth as possible. A cherry picker, on the other hand, selects the data that support his argument and presents only them, willfully excluding numbers that are less supportive, even if those numbers may be closer to the truth. Cherry-picking is lying by exclusion to make an argument seem more compelling. And it’s extremely common, especially in the political world. (It’s also very common in the scientific world, thanks to a phenomenon known as “publication bias.” Peer-reviewed journals cherry-pick the most exciting papers, selecting them for publication. This means that papers with spectacular results are published in high-profile journals while less sexy ones (including negative results) are relegated to lesser journals or aren’t published at all. Publication bias distorts science, making new drugs, for example, seem more effective than they actually are.) Every politician is guilty of it, at least to some extent.
Al Gore is guilty of cherry-picking in his film An Inconvenient Truth. At the heart of the 2006 movie is a breathtaking and disturbing sequence where he shows computer simulations of what global warming will do to the surface of the earth. In a series of maps, he shows the world’s coastlines disappearing under the rising oceans. Much of Florida and Louisiana will be submerged, and most of Bangladesh will sink beneath the waves. The animations are stunning, leaving viewers with little doubt that global warming will dramatically reshape our planet. However, those animations are based upon a cherry-picked number: Gore’s pictures assume that melting ice will drive the sea level up by twenty feet.
Lots of scientists have tried to model the effects of global warming, and most have come to a very different conclusion. They tend to agree that global warming is real, that human activities are responsible for a sizable portion of that warming, and that the sea level will indeed rise over the next century. (Despite my singling out Al Gore for cherry-picking, there are unambiguous data that show that global warming is occurring. It’s just that sea levels aren’t going to rise twenty feet anytime soon.) There’s an outside chance that the sea level will rise by twenty feet or more if a very worst- case scenario occurs (such as the near-complete melting of the ice sheets in Greenland or West Antarctica). However, most serious estimates project a sea level rise much lower than what Gore used. Some climatologists say the oceans will rise two feet or so in the next century; some go as high as four feet””these are the best scientific guesses right now. Yet Gore ignores these more modest estimates and picks the most extreme model of sea level rise””the twenty-footer””so he can flash his dire graphics on the screen. It wowed the audiences, but it was cherry-picking.
Not. And most certainly not a good example of cherry picking.
Seife makes a bunch of mis-statements or poorly worded statements, but fundamentally, in his main accusation, he is just repeating a well-worn, but false talking anti-Gore talking point about the movie.
In fact, Gore did not specify that the 20 feet of sea level rise would occur over the next century.
This has been pointed out by so many different people that even a minimal amount of online research by Seife would have uncovered it. Just google “Gore an inconvenient truth Greenland” and you’ll even find Skeptical Science‘s post (#3), which links to an unofficial transcript of the movie. So we know precisely what Gore said on the matter:
“If Greenland broke up and melted, or if half of Greenland and half of West Antarctica broke up and melted, this is what would happen to the sea level in Florida. This is what would happen in the San Francisco Bay. A lot of people live in these areas. The Netherlands, the Low Countries: absolutely devastation. The area around Beijing is home to tens of millions of people. Even worse, in the area around Shanghai, there are 40 million people. Worse still, Calcutta, and to the east Bangladesh, the area covered includes 50 million people. Think of the impact of a couple of hundred thousand refugees when they are displaced by an environmental event and then imagine the impact of a 100 million or more. Here is Manhattan. This is the World Trade Center memorial site. After the horrible events of 9/11 we said never again. This is what would happen to Manhattan. They can measure this precisely, just as scientists could predict precisely how much water would breach the levee in New Orleans.”
Most famously, “Al Gore responds to the UK court case that questions An Inconvenient Truth.” Gore (via Kalee Kreider) responded:
Since the Fact Checker has afforded us the opportunity to respond specifically to the nine points at issue, we will do so.
Ice-sheet driven sea level rise. Scientists agree that the melting of Greenland or the West Antarctic ice sheet would raise sea levels around six meters. The movie does not give a timescale for when that melting might occur. There are uncertainties in the scientific community about the timescale, but this uncertainty does not negate the need to seriously consider these scenarios when considering solutions to the climate crisis. IPCC estimates a sea level rise of 59 centimeters by 2100. However, they exclude any water contributed by the melting of Greenland or Antarctica because they don’t know when either could happen. We hold our fate in our own hands. If we conclude a strong treaty–or if we pass strong legislation in the US to cut the pollution that causes global warming, it could make a real difference to our future and that of our children. Dr. Jim Hansen, head of NASA’s Goddard Institute for Space Studies and someone whom we trust, has said that we may see several meters of sea level rise by 2100 if we do not act.
You can accuse Gore of not stating when the 20 feet might happen — but not of making a quantitative error. And what he did certainly isn’t “cherry picking.”
It’s worth repeating what the climate scientists of RealClimate said about the supposed SLR error:
Ice-sheet driven sea level rise. Gore correctly asserted that melting of Greenland or the West Antarctic ice sheet would raise sea levels 20ft (6 meters). In the movie, no timescale for that was specified, but lest you think that the 20 ft number is simply plucked out of thin air, you should note that this is about how much higher sea level was around 125,000 years ago during the last inter-glacial period. Then, global temperatures were only a degree or two warmer than today – and given that this is close to the minimum temperature rise we can expect in the future, that 20 ft is particularly relevant. The rate at which this is likely to happen is however highly uncertain as we have discussed previously.
Yes, many well-known projections of climate change end in 2100 — but that doesn’t mean they all have to be. Quite the reverse: Decisions about whether or not to restrict greenhouse gas emissions should certainly not be based solely on what happens over the next 90 years (see NOAA stunner: Climate change “largely irreversible for 1000 years,” with permanent Dust Bowls in Southwest and around the globe). That is especially true in the case of SLR since, if we don’t act, seas are likely to keep rising 6 to 12 inches a decade (or more) for centuries until we are an ice free planet. How precisely are people supposed to adapt to that?
Also, the best science suggests that if we don’t act soon, 20 feet of SLR may be utterly unavoidable:
Seife’s accusation against Gore is simply wrong. On top of that, his analysis is out of date. This particular assertion is simply misleading:
Some climatologists say the oceans will rise two feet or so in the next century; some go as high as four feet””these are the best scientific guesses right now
The phrase “some go as high as four feet” is designed to leave readers the distinct impression that that is the plausible upper bound. In fact, assuming that we keep doing nothing, four feet is close to the lower bound for what most of the climatologists and glaciologist I know believe is in store for 2100 (see Coastal studies experts: “For coastal management purposes, a [sea level] rise of 7 feet (2 meters) should be utilized for planning major infrastructure”). The literature is quite clear that we could easily go above 4 feet (see Sea levels may rise 3 times faster than IPCC estimated, could hit 6 feet by 2100):
If Gore had said 20 feet by 2100, that would have been inappropriate. But it isn’t even true that his 20 feet is “the most extreme model of sea level rise.” Long before Seife’s book was published we had, for instance, this study:
Science: CO2 levels haven’t been this high for 15 million years, when it was 5° to 10°F warmer and seas were 75 to 120 feet higher “” “We have shown that this dramatic rise in sea level is associated with an increase in CO2 levels of about 100 ppm.”
In the coming decades, as policy-makers, and the public, and the media wakes up to the painful reality of what unrestricted greenhouse gas emissions are doing now — and likely to do in the future — 20 feet won’t be seen as an “extreme” projection in the least.
An ice free planet, by the way, would mean some 250 feet of sea level rise. While that would probably take many centuries, the fact is scientists haven’t spent a lot of time modeling the impact of the kind of extreme Arctic warming we face on our current emissions path (see M.I.T. doubles its 2095 warming projection to 10°F “” with 866 ppm and Arctic warming of 20°F). Certainly close to 20 feet of SLR by 2200 isn’t out of the question if we hit 1000 ppm in a century.
In any case, Seife got it quite wrong and those reviewing the book didn’t bother to spend even a few seconds online to get the facts straight.
Hmm. I thought there was a word for when you believe something that isn’t true but that you want to be true:
Although Seife never says so explicitly, the book’s title alludes to “truthiness” “” the Word of the Year in 2005, according to the American Dialect Society, which defined it as “the quality of preferring concepts or facts one wishes to be true, rather than concepts or facts known to be true.”
Yes, irony can be so ironic.