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January 7, 2008 | No comments

A safe, but misleading, prediction about global warming

Reuters’s, on 3 January, had this headline, “2008 to be in top 10 warmest years say forecasters.”

A quote:

2008 will be slightly cooler than recent years globally but will still be among the top 10 warmest years on record since 1850 and should not be seen as a sign global warming was on the wane, British forecasters said.

Where to start? First, the anemic forecast. Suppose the global mean temperature is, as predicted by several models, increasing, though this increase is subject to fluctuation from year to year, such that for one or two years the temperature might actually decrease, but in the long run, the temperature will still increase. Call this scenario the increasing temperature climate. It is important to emphasize that the increasing climate schema is consistent with both a significant man-made component and with the change being due to external causes. Now suppose, as has also been proposed, that the global mean temperature instead followed this cartoon, depicting a cyclically-changing climate:

Global mean temperature cartoon

This cartoon (and those based on other potential climate scenarios) is also consistent with either man-made climate changes or with the changes being due to external causes. It is just that, in this picture, the man-made component is harder to quantify. This is because of the trivial truth that man must influence the climate (see this), and that this influence will either be trivial or significant.

So it is a tautology to say that either man-made global warming is significant or it is not. One of those conditions must be true. It is also observed that the global mean temperature is correlated from year to year, so it is a fact that the temperature is somewhat constrained, in the sense that we will see little change from year to year, no matter whether mad-made global warming is significant or not, and regardless whether a general increasing or a cyclic climate holds.

Lastly, it is also the case that the global mean temperature has been increasing since the late 1990s until 2006. In 2007, the temperature decreased.

So the prediction that “2008 will be in the 10 ten warmest years” has an overwhelming probability of being true regardless whether man-made global warming is significant or not, and regardless whether an increasing or cyclic climate holds. That is, no matter what, this prediction is probably true, and it is useless as its intent was to give indirect evidence that the increasing climate scenario holds and that the man-made component of global warming is significant. It does neither such thing. Presenting this prediction as news is a clever debating tactic, but it is misleading, because the alternatives are not presented, even though the forecast is just as much evidence for them.

“‘The fact that 2008 is forecast to be cooler than any of the last seven years does not mean that global warming has gone away,’ said Phil Jones, director of climate research at UEA.” Jones is right, partially. But he forgot to say, “That fact the 2008 is forecast to be cooler than any of the last seven years also means that it might true that the climate is cyclic and that man has no real influence on it.”

This forecast is not additional evidence that an increasing climate or that man-made global warming holds.

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Asinine comparison of holocaust deniers and honest scientists

Some guy named Joel Connelly at the Seattle Post-Intelligencer has written another one of those “We must do something now” global warming articles. What makes his piece distinct is that he compares those who express honest skepticism in global warming claims with those who deny the holocaust.

This sort of thing is exceedingly moronic, yes, but it is one more empirical observation that shows Godwin’s Law continues to hold. That law states:

As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one.

And let’s not forget that exquisite corollary of Godwin’s Law, Benford’s Law of Controversy:

Passion is inversely proportional to the amount of information available.

Connelly’s piece follows Benford’s Law, too, because of the one thing that I find happening with increasing frequency. Here’s a quote:

Nobody is certain what will happen.

So far, however, change has proceeded at a faster pace than even pessimistic scientists predicted a few years ago.

Who could have forecast a 2-degree rise in Antarctica’s temperature in just 35 years? Nobody forecast the breaking off of giant Antarctic ice shelves. The rapid shrinking of the Arctic ice pack has surprised researchers…

Nobody is “certain what will happen”, except Connelly of course, because he then uses the empirical fact that scientists with their best models have failed to predict actual observations to argue that we should believe those scientists’ models and that “we must act quickly, within a decade.”

My friends, the opposite is true. If scientists are failing to predict actual observations, then we should have increased skepticism that what those scientists are saying will actually come to pass. At the very least, we should increase the error bounds, the “plus or minuses”, that accompany their predictions.

It also does not follow that because the model error is negative, i.e. that more warming took place than was predicted, that the situation is even worse than we thought, and that even faster warming rates will occur. This argument is a logical fallacy unless it is conjoined with the additional premiss that “warming must occur, and that if our predictions show that less warming will occur than actually does happen, then even greater warming will take place.” But if you assume that premiss, then your argument is circular, and therefore useless.

Failed predictions should not lead to increased passionate belief in those predictions.

January 6, 2008 | No comments

Mr. Word’s definition of the day: to change

“To alter; to make different; to cause to pass from one state to another; as, to change the position, character, or appearance of a thing; to change the countenance.” — Webster, 1913.

Barack Obama is the official candidate of change. In last night’s debates in New Hampshire, Hillary Clinton boasted that she was a bigger candidate of change than Obama, and further, she had been changing for thirty-five years! Mitt Romney, the next day, agreed with his Democrat cousins, when at a rally he said, “What is needed is change.” All of the other candidates, both Democrat and Republican, agree, more or less stridently, that change is a requirement for the new president.

By the way, an informal statistical count I conducted in last night’s debate shows Fred Thompson using this word the least. Obama, of course, used it the most.

Change is such a strong word, so often found in political rhetoric, because it is infinitely malleable. What makes it so powerful is that you define, to yourself, what change means. You then project this definition onto your candidate of choice and assume his definition is the same as yours. So when the candidate speaks of change, it is as if he is speaking directly to you.

That is, as long as the candidate does not go too far and make a statement that actually contradicts what your definition is. So the more the candidate vapidly speaks in generalities about change and concurrently avoids specifics, the better it is for that candidate, in the sense that use of change has the power to convince the largest number of people that the candidate believes as they do.

Change is also a weak, nearly meaningless, word because anything that happens in the future will be a change from what happened until now. It is hardly necessary to say that George Bush will not be president next year. His exit will be a change that whomever wins the election will bring. World events will certainly change by 2009, and the new president will certainly have to do things differently in the future to meet these exigencies. The membership of Congress will certainly be different in 2009, and this new Congress will put forward new bills which the new president will have to sign or not. So again, the new president will have produced change.

Change, then, is certain. No matter who is elected, that person must bring change, and so every candidate is therefore a candidate of change. It is impossible that they not be so. Therefore, to seek out the candidate of change is a useless activity.

Though perhaps you were thinking, what you really meant by change was, for example, when Obama said, “We need a change in foreign policy.” You assumed he meant by this an “abandonment of the Bush ‘Doctrine’.” And you might be right, but this was only a guess on your part. It is proof, however, that it was you who were defining what change meant. You cannot be sure it is what Obama also thinks unless he explicitly says what a change in foreign policy actually is.

As a note, it is also empty for a candidate to say, “We need a change from the Bush ‘Doctrine'” unless that candidate is also prepared to explicitly define what the “Bush Doctrine” is.

January 5, 2008 | 1 Comment

How much does winning Iowa and New Hampshire help?

On the earlier poll thread, a reader asked “What’s your opinion about the statistical summary of past results of Iowa caucuses and New Hampshire primaries?” pointing out data from Neatorama.com. The Neatorama blogger had tables like these below, but made separate tables for Iowa and New Hampshire and included information about who won the general election. I thought it would tell a better story by combining the primaries and by eliminating the general election data because the main question is who will be nominated.

The tables list who won each of the primaries and who was eventually nominated. So, does winning the first two primaries help? Certainly.

Democrats

Year Won Iowa Won NH Nominated
1976 “Uncommitted” Jimmy Carter Jimmy Carter
1980 Jimmy Carter Jimmy Carter Jimmy Carter
1984 Walter Mondale Gary Hart Walter Mondale
1988 Dick Gephart Michael Dukakis Michael Dukakis
1992 Tom Harkin Paul Tsongas Bill Clinton
1996 Bill Clinton* Bill Clinton* Bill Clinton*
2000 Al Gore Al Gore Al Gore
2004 John Kerry John Kerry John Kerry
2008 Barack Obama ? ?
*Ran Unopposed

Republicans

Year Won Iowa Won NH Nominated
1976 Gerald Ford Gerald Ford Gerald Ford
1980 George H.W. Bush Ronald Reagan Ronald Reagan
1984 Ronald Reagan* Ronald Reagan* Ronald Reagan*
1988 Bob Dole George H.W. Bush George H.W. Bush
1992 George H.W. Bush* George H.W. Bush* George H.W. Bush*
1996 Bob Dole Pat Buchanan Bob Dole
2000 George W. Bush John McCain George W. Bush
2004 George W. Bush* George W. Bush* George W. Bush*
2008 Mike Huckabee ? ?
*Ran Unopposed

Combining data from both parties, there were 4 candidates who won both Iowa and NH, and in each of those 4 cases those candidates went on to receive the nomination. Of course, it is not guaranteed that winning both will secure the nomination, but it does make it very likely. This ignores those candidates who ran unopposed, as, obviously, their elections were never in doubt.

Candidates who won at least one of Iowa or NH won 11 out of 12 times, or 92% of the time. Only one time did a candidate not win at least one primary but still went on to win the nomination; that was Bill Clinton in 1992.

This implies the obvious: that by this coming Tuesday, we’ll be nearly sure who the top two candidates are for each party, and if either Obama or Huckabee wins New Hampshire, it’ll be a safe bet that they’ll also win the nomination.

You could separate out the data for each party, but there is no great reason to do so statistically.? The results also are conditional on the past “political situation”, which is largely unquantifiable.? If we assume that today’s politics are not different than those from 1976 until present, then the results are useful.? But if they have somehow changed—e.g. Guliani’s strategy of ignoring Iowa and NH—then these results are far less helpful.