Aug
11
2007

A computer error leads to bad climate data: The sudden jump in temperatures around January 2000 was caused by a faulty formula. New calculations show many years were actually cooler than previously thought.  (Source: NASA Goddard Institute for Space Studies)
A computer error leads to bad climate data: The sudden jump in temperatures around January 2000 was caused by a faulty formula. New calculations show many years were actually cooler than previously thought. (Source: NASA Goddard Institute for Space Studies)

We here at Science Buzz have discussed global warming a time or two. And long-time readers know that I am The Science Museum’s resident global warming skeptic. Not a denier – I recognize that the Earth’s temperatures have been generally increasing over the last 25 to 30 years, and I’ll admit that human-produced carbon dioxide could well be a contributing factor. However, I am skeptical about claims that human activity is the sole or even primary cause of this warming; that there is a simple, direct correlation between our actions and global climate; or that the planet is headed toward some sort of ecological disaster in the next 10 years if we don’t do something drastic now.

Toward that end, I keep an eye on the various global warming threads, and try to temper the more intemperate comments made by those who hold different views. (And they do the same for me, of course.) So, in the course of a debate, if someone says “the Earth is warming,” I correct them by pointing out that the Earth has warmed: global temperatures rose in the 1980s and ‘90s, peaked in the US in 1998, and have held steady or dropped slightly since.

I have recently learned that this was wrong. As painful as it is for me to admit, I must set the record straight: temperatures in the US did not peak in 1998. They actually peaked in…

1934

In 1934, the world’s population was a fraction of what it is today. (One-sixth, more or less.) Manufacturing and industry were smaller. The number of cars and the miles traveled in them were far fewer. Commercial air travel – a huge producer of greenhouse gases – was in its infancy.

(1934 was also the year my mother was born and, in a coincidence science has thus far been unable to explain, the year Yoko Ono was born.)

And yet despite the lower levels of greenhouse gas, 1934 was warmer than any other year, before or since. And while global temperatures had been generally increasing since about 1890, they leveled off around 1940 and even took a slight dip in the 1970s. All of which indicates that record-high temperatures may not be the harbinger of doom so many assume them to be.

So, how could I have made such a drastic mistake? Well, I’m not the only one. Y’see, I was relying on a temperature chart produced by NASA scientists Reto Reudy and James Hansen. Their graph showed temperatures spiking in the late ‘90s, and staying near that peak.

Of course, other people were studying that chart, too. One of them, Steve McIntyre, thought it looked a little fishy. So he asked Hansen for the formula he used to produce his chart. Hansen, operating in the spirit of openness and transparency that is the hallmark of science and a requirement of the federal government…refused. (Other scientists have also accused some federal agencies of not sharing their data so it can be reviewed.) So McIntyre reverse-engineered the formula from the published data. And he found something interesting.

Temperature data from many reporting stations around the country suddenly jumped around the year 2000. After some digging, McIntyre found an error in the formula used to process the data. As a result, Reudy and Hansen reported many years as being warmer than they really were.

(Is this the same James Hansen who has accused the Bush administration of playing politics with science, trying to suppress views that contradict their positions and cherry-picking data that advances its agenda? Why, yes it is!)

NASA has recomputed the figures and issued a new set of corrected data. It now shows that five of the ten warmest years on record occurred before World War II, when global temps leveled off and later fell. Four of the years in our current decade which were supposed to have been near record highs were actually colder than 1900.

Minnesotans can be proud that their state played a role in uncovering this mistake. It was data at the Detroit Lakes station that first led McIntyre to believe something was amiss.

So, what lesson do we learn from all this? That I need to be more skeptical. I have to stop believing everything I read in the New York Times. I need to recognize that even rocket scientists can sometimes make mistakes.

So my promise to you, dear readers, is I will check my sources and do my best never to fall for this sort of mistake again.

Your Comments, Thoughts, Questions, Ideas

JGordon's picture
JGordon says:

Wait... so are you trying to say that your mother is Yoko Ono?
Gene, you have simply gone too far on this one.
Global warming is nothing compared to the problems that woman has caused (although, I suppose some argue against that theory as well).

posted on Sat, 08/11/2007 - 12:58pm
Gene's picture
Gene says:

Don't worry, Kyoto, mummy's only looking for a hand in the snow...

posted on Sat, 08/11/2007 - 11:15pm
bill blass's picture
bill blass says:

Global warming is a scam perpetrated by research scientists to get government grants.

posted on Sat, 08/11/2007 - 2:33pm
Raymond's picture
Raymond says:

Yeah, because everyone knows how much effort the government is putting into fighting global warming.

Those lousy scientists. They live like kings off of that grant money. It's getting so difficult these days to tell climate scientists apart from professional athletes and rock stars.

posted on Sat, 08/11/2007 - 6:05pm
Gene's picture
Gene says:

It's not about money; it's about getting the facts straight.

posted on Sat, 08/11/2007 - 11:14pm
Stosh's picture
Stosh says:

Now if you were a climate scientist, and all the money was going on the side of global warming, where would you, wanting, for instance, to eat, go? And wouldn't you lick the hand that feeds you?

posted on Sat, 08/18/2007 - 5:41pm
JGordon's picture
JGordon says:

That's actually the reason no one feeds me any more. Also, please control your commas - they're upsetting the younger readers.

Okay, it makes sense that new theories and information should be tested, and not simply accepted at face value - I like that part of this discussion - but I think that the argument that scientists are focusing on global warming to get more money is ridiculous. It seems like completely the wrong way to call their results into question - it's insulting to the intellectual integrity of people who, I'm sure, take what they do very seriously (although I suppose some would argue that their science isn't the greatest in the first place, but I think that's a different point).

I'm not sure that there's this massive pile of resources for climate scientists to "lick" at either - again, I don't want to go on about things I don't really know, but I have the feeling that the parties interested in showing that global warming is an entirely natural phenomenon have a lot more resources than those that are trying to prove the opposite.

I mean, if I were a scientist looking for a steady stream of grant money, I'd start inventing new ways to kill people (and global warming doesn't count here).

posted on Mon, 08/20/2007 - 12:04am
Gene's picture
Gene says:

I don't believe the argument is that scientists focus on global warming to "get more money." Rather, it is the global warming became a funding priority under the previous Administration (and largely remains so today). Grants that position themselves as investigating anthropogenic (man-made) global warming have a better chance of getting some of that money. Which means three things:

1) scientists studying global warming get funded.

2) scientists studying other things can increase their odds of getting funded if they can add a "global warming angle"

3) scientists skeptical of anthropogenic global warming have a harder time getting funded

Now, there is nothing inherently wrong about 1) and 2). Happens all the time. The Nation Science Foundation decides they want more research on, say, nanotechnology, and all of a sudden, folks who have been studying nanotechnology start writing lots of grants and getting them funded. Scientists who study other things try to add nano to their studies, in order to qualify for this funding. When there are limited resources to go around, this sort of thing happens. It makes sense for the funding agency to set priorities, and it makes sense for scientists to tailor their research to fit those funding priorities. Like I said, happens all the time.

The problem is #3. If NSF only funded research into the benefits of nanotechnology, and systematically declined to fund any study into its possible negative effects, then they would be using federal funds to slant the research agenda in a particular direction. Now, I have never heard of NSF ever doing anything remotely like that for nano. But, some climate scientists have argued that various funding agencies provide no money (or very little money) for climate research that refutes the anthropogenic model.

posted on Mon, 08/20/2007 - 8:30am
JGordon's picture
JGordon says:

I see. But, still, the NSF funds proposals, right? Not specific results? You'd think that there would still be plenty of studies that go either way, if that were the case with global warming.
Or does the NSF honestly only fund studies with a biased direction and implied results ( like "the anthropogenic causes of global warming," as opposed to "the causes of global warming")?
I think I can guess your answer, Gene, but, still, I'm not entirely convinced. It's good to know, though.

posted on Mon, 08/20/2007 - 10:02am
Gene's picture
Gene says:

It is my understanding that every research proposal contains the hypothesis the research will attempt to prove. And there are those who claim that studies attempting to prove the anthropogenic hypothesis are funded at a much higher rate than those attempting to disprove it.

You find what you are looking for. If funding agencies (and I don't want to pick on NSF here -- I was only using them as an example) support research that looks for evidence supporting an anthropogenic cause, and fund little or no research looking for evidence to refute that hypothesis, then there will be no great surprise over what they find.

posted on Mon, 08/20/2007 - 11:36am
Liza's picture
Liza says:

Well, sure. But you're suggesting that every hypothesis that is posited is also proven. And I'm not sure that's the case.

I think the trouble is this: people tend to publish their positive findings. But do they also publish their negative results? Maybe, but probably not always. And that has at least two consequences. 1) Scientists probably end up duplicating experiments not to reaffirm them but because they don't know they've been done before since the negative results aren't published. And 2) it's easy to believe in bias and manipulation of data if you don't think you're really seeing the whole picture.

If rigorous science is being done to answer good, testable questions, we should see a pattern of data emerging no matter what the initial hypotheses are. Yes?

posted on Mon, 08/20/2007 - 12:43pm
JGordon's picture
JGordon says:

But do you think that climate scientists looking for anthropogenic causes are being intellectually dishonest? I mean, if they were completely off-base, you'd think that they'd not find what they were looking for occasionally, or more than occasionally, despite their original hypotheses. Is the NSF (sticking with the same example) funding a bunch of anthropogenic-cause hypotheses that are disproved for every one that is proved? (And that's not a rhetorical question - I'm actually curious.) Or are you just saying that their science is good, but because anthropogenic-cause research is all we see, the whole view of global warming is unfairly weighted to one side?
If this is the case, people should obviously take that into consideration, although the anthropogenic causes for global warming are the only ones we can do anything about (right?) and maybe deserve a little extra scrutiny. Unless you think that human contribution to global warming really is negligible. Or, I suppose, one might say that we can't know yet if it is negligible or not with the sort of research going on.
I hate to fall back on "what if you're wrong" as an argument, but, seriously, what if you're wrong? At worst, the focus on anthropogenic causes of global warming is a waste of scientific resources (which is bad, I admit), but the alternative is potentially much worse.

-Oops - I posted this before I saw Liza's comment, and there's a little overlap.

posted on Mon, 08/20/2007 - 1:25pm
Gene's picture
Gene says:

Liza, J and I all work for The Science Museum. Liza has this wonderful chart on her cubicle wall—a timeline that notes the date that evolution began to be taught in public schools. Since that date, crime has gone up, violence has gone up, divorce rates have gone up, drug abuse has gone up, etc. etc. etc. Obviously, teaching evolution has unleashed a tidal wave of social ills!

(Liza notes that ridiculous charts and graphs have also gone up over that same time frame. ;-)

Of course, this is ridiculous. Correlation is not causation. There are other, much more plausible explanations for all these things. But, a person with a particular worldview interpreted real-life evidence in the light of his hypothesis. Some people have suggested that something similar—though far less blatant and absurd—happens with climate science.

Liza says:

[Y]ou're suggesting that every hypothesis that is posited is also proven…

Not necessarily. But it’s hard to “prove” anything in the natural sciences. Systems like climate are extraordinarily complicated. Juggle the numbers enough different ways, and you’re likely to come up with at least a mild correlation. It is possible to have a hypothesis that is in fact incorrect, or partially correct, or correct but only a minor factor, and have evidence from the complex system seem to support it. (I believe scientists call this kind of result an “artifact.”)

Liza also says:

[I]t's easy to believe in bias and manipulation of data if you don't think you're really seeing the whole picture.

Well, that gets back to my original post. As I see it, Hansen made three mistakes. The first was the error in his calculations. That was a simple human mistake. Completely forgivable—we all make them. The second, though, appears to be bias. Now, I haven’t read anything to confirm this, but it’s not hard to imagine that Hansen, a firm believer in anthropogenic warming, ran his data, got results that matched his hypothesis perfectly, and so didn’t go back and check them carefully enough, or to look for the cause of the very sudden jump in his graph in January 2000. His third mistake was in not releasing all his data and procedures to the scientific community. This is a standard part of the scientific process. Why he didn’t do it, even when requested, I cannot say.

Finally, Liza asks:

If rigorous science is being done to answer good, testable questions, we should see a pattern of data emerging no matter what the initial hypotheses are. Yes?

Not if the questions are limited to those assuming a particular view. Let’s say the government funds 100 studies looking for a link between human activity and global warming, and 75 of them come back positive. Pretty strong pattern, right? Well, no. Where are the 100 studies of other possible causes for global warming – studies of solar cycles, geologic climate patterns, naturally-produced gasses, etc.? What if those studies come back positive 90% of the time? What if their impact on climate is greater? What if their impact is weaker than humanity’s but, when added together, become the dominant factor? We won’t know until someone funds those studies.

JGordon asks:

[D]o you think that climate scientists looking for anthropogenic causes are being intellectually dishonest?

Not at all. I do think they are human. And as we all know, humans have a tendency to see what they want to see, and to tenaciously defend any position they have invented themselves in heavily.

JGordon also asks:

[A]re you … saying that their science is good, but because anthropogenic-cause research is all we see, the whole view of global warming is unfairly weighted to one side?

Yes, that is a pretty good summary of my point.

Finally, JGordon asks:

[W]hat if you're wrong? At worst, the focus on anthropogenic causes of global warming is a waste of scientific resources (which is bad, I admit), but the alternative is potentially much worse.

You partly answered the question yourself when earlier you said “I suppose, one might say that we can't know yet if [the human contribution to global warming] is negligible or not with the sort of research going on.” Exactly. Until we’ve studied the full climate picture, we won’t know what role we are playing, and therefore we won’t know how or even if we should change.

I believe we could all stand to use less energy. And we could all try to pollute less. But some of the proposals out there to combat warming are quite extreme. I read one activist who said we needed to cut carbon emissions by 95%! That would literally put us back in the Dark Ages! Other proposals, if less drastic, would still have a crippling effect on the world economy, and substantially reduce the standard of living for every person on the planet.

So, let me turn the question around. What if you’re wrong? Are you willing to consign six billion people to a life of misery before we’ve fully examined all the possible influences on this highly complex, highly variable system?

posted on Mon, 08/20/2007 - 8:51pm
JGordon's picture
JGordon says:

"Are you willing to consign six billion people to a life of misery before we’ve fully examined all the possible influences on this highly complex, highly variable system?"

Well, "a life of misery" seems a little extreme, but, in a word, yes. As long as I can do it one person at a time. Six billion is just such an overwhelming number.

posted on Tue, 08/21/2007 - 3:18pm
jrlogan's picture
jrlogan says:

I read a couple of years ago that according to the seed planting charts on the back of seed packages that the temerate zones of North America were actually getting cooler. Hmmm!.

posted on Sat, 08/11/2007 - 10:12pm
Gene's picture
Gene says:

Interesting....I recently heard just the opposite. Anybody out there have some hard data on this?

posted on Sat, 08/11/2007 - 11:16pm
roxy's picture
roxy says:

this is cool a little bit not really

posted on Mon, 08/20/2007 - 1:58pm
Anonymous's picture
Anonymous says:

Maybe some data proves incorrect--but the fact remains that the glaciers are melting at a fast clip over these past ten-fifteen years. That speed of loss has not been found in the pre-1990s. Right? So--global warming is still a threat as far as I can tell.

posted on Wed, 09/05/2007 - 11:27am
Gene's picture
Gene says:

It depends where you measure -- I understand the Greenland ice cap is getting thicker. As for speed, I don't know how long that has been accurately measured. But we do know that glaciers have advanced and retreated many times, including within the past couple thousand years.

posted on Wed, 09/05/2007 - 11:40pm
groschen's picture
groschen says:

I just love this but it is very expensive Thanks anyway

posted on Wed, 09/05/2007 - 12:04pm
Anonymous's picture
Anonymous says:

Back in the 1960's and 70's schools were teaching that the earth is moving into an ice age.
No one teaches that now but maybe everyone should look at it this way.
The earth still moving out of the last ice age. Who knows how long that takes.

posted on Thu, 09/06/2007 - 1:47pm

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