A gem from James - HADCRUT4 also says 2010 was the Best In Show for bad temperature news

Two months old, but hasn't had much play that I've seen.  The HADCRUT global surface temperature dataset, often preferred by climate denialists who play at such things, got an upgrade with more Arctic coverage.  Like other datasets, that Arctic climate amplification is enough to put HADCRUT4 2010 over the top of previous record holders 1998 and 2005.  I guess the denialists won't play with it as much now.

I have no idea if the difference for 2010 is statistically significant, but that's not an adverb that denialists care about.

Climate betting update - back to where we started, and I'm not worried

Several weeks ago I received my annual friendly email from David Evans, my betting partner/opponent over future temperature increases, with the 2011 temp data from GISS.  Bet details are here, summary is that I've bet $9,000 and David $6,000 for a series of decade-plus bets over whether temps will increase somewhat near the IPCC projected rate or at a much lower rate.

David mentioned that the five-year average we're betting on is, for 2009, back to where we started in 2007, which would be very bad for my side of the bet, but he also politely added that we've had some La Ninas to affect things.  I'm not too worried for my pocketbook - the five year average for 2009 overlaps too much with 2007 to expect a lot of movement.  The five year average for 2012, which we won't know until 2015, will be the first that has no overlap.  First bets pay out or are voided in 2020, so as David says, this betting will take a while.

One way to look at it is to assume a counterfactual that the bet started in 1989 and ended in 2009 - fair from my viewpoint of expecting past rises to continue/accelerate, but not what David expects.  My calculation is that I win all three of the low end bets, void one of the high end bets, lose the other two high end bets, and come out ahead $1000.

Not much other activity from me on the climate betting front, and I haven't heard much from others either besides William's sea ice, unless I've missed it.  I've been thinking that sea level rise might be less noisy than temps, allowing shorter bet periods and maybe using three year averages.  Maybe will look into that later.

Last year's betting update here.

Climate probabilities have multiple outcomes over time (Roger forgets the Fourth Dimension)

At the risk of repeating Roger Jr.'s mistake of not really knowing what I'm talking about, it seems like the fact's been obscured that we're betting not on one climate outcome at a single point in time but at multiple points in time.

To go back to the betting on a weighted die analogy, we're not just betting on a single outcome, but how often the die face saying "getting even warmer" shows up at each point in time as the die rolls. And we're able to make new bets at each point in time. From a policy perspective, we're able to use past experience with models to decide if we want to continue to rely on those predictions.

A related flaw in the delayist/denier argument is the alleged long-term consequences of policies - based on supposedly incorrect predictions of change - won't actually happen. If the predictions are wrong, we can stop investing in seawalls and solar panels in a decade or two. We'll have multiple outcomes over time to test those predictions.

(Per the comments, the title has been updated.)

Climate betting update for 2010

I had my annual friendly email exchange with betting partner/opponent, David Evans, several weeks back. Our bet:

We have three bet periods -10, 15, and 20 years - and two bets for each period - an even-odds bet and a 2:1 bet in David's favor. The even-odds bet centers around a temperature increase rate of 0.15C/decade with a 0.02 void margin on either side (bet voids if temps increase between .13 and .17C/decade). The 2:1 bet centers on 0.1C/decade with a .01 void margin. Even-odds bets are for $1,000 each, and the 2:1 bets increase over time, with me betting $1,000, $2,000 and $3,000, and David betting half that. My exposure is $9,000; his is $6,000.

We use the NASA GISS dataset, and the baseline is the five-year average for 2007 (.55C above the long-term average), compared to five year averages of each of the three bet periods. Years 2010 through 2014 won't "count" in the sense of not being measured in the five year averages, but they will give a sense of who's winning.

So who's winning? Interestingly, David and I both focused on the news that was bad for our own side. In 2010, the global average temp was a record .63C above the long-term, an increase of .08C in just three years from 2007's multi-year average, and a pace that far exceeds what I need to win all of the bets. That's the perspective David took.

By contrast, I compared five-year averages: we're now able to calculate the five-year average centered on 2008, and it's only .01C above 2007's multi-year average. The reason for the small change is that the only difference between the averages is that 2007's average included the record year 2005, while 2008's average dropped the record year 2005 and replaced it with the record year 2010. At a .01C annual increase rate, I will lose half of my bets and void the other half.

Looking forward to this time next year, our perspectives might shift again, assuming 2011 plays out as another warm year but La Nina-cooled from 2010. The five year average for 2009 will eliminate 2006, which was only typical and cooler than 2005, and replace it with 2011. Any 2011 temperature above .58C should put me in good shape for the five-year average, even if it's not as blistering as 2010. So we'll see.

Meanwhile, James Annan continues his too-easy path to climate betting riches with Russian skeptics. I've been meaning to reach his betting opponents to see if they agree that their goose is cooked, and if not, whether they'd like to double down.

UPDATE: The skewed prediction-market bet that exaggerated the short-term warming anticipated by the IPCC turned out to be insufficiently skewed, and the "Al Gore side" won the bet. The website promoting the bet on behalf of denialist Scott Armstrong has been mysteriously silent about this development, talking only about a longer, proposed bet that's still artificially skewed by lying about the predicted short-term warming. And just in case that bet disappears down the memory hole, here's how Theclimatebet.com describes it:

“Now, assume that Armstrong and Gore made a gentleman‟s bet (no money) and that the ten years of the bet started on January 1, 2008. Armstrong‟s forecast was that there would be no change in global mean temperature over the next ten years. Gore did not specify a method or a forecast. Nor did searches of his book or the Internet reveal any quantitative forecasts or any methodology that he relied on. He did, however, imply that the global mean temperature would increase at a rapid rate – presumably at least as great as the IPCC‟s 1992 projection of 0.03°C-per-year (NOTE: untrue statement, no short term IPCC prediction was made in 1992, and later reviews made lower decadal predictions - ed). Thus, the IPCC‟s 1992 projection is used as Gore‟s forecast.”

Finally, the small bet I've got with Joe Romm on whether 90% of Arctic sea ice will disappear by 2020 (with me taking the cold side) chugs along. Joe does have a chart here showing that recent decline rates, projected linearly, would have him winning. I'm not so sure, although I'm also less sure of my side than I was when I took the bet.

Christy lays down an (unclear, skewed) marker

From a good and unsettling news article on accelerated glacier flow and melting in Greenland:

John R. Christy, a climatologist at the University of Alabama in Huntsville who is often critical of mainstream climate science, said he suspected that the changes in Greenland were linked to this natural variability, and added that he doubted that the pace would accelerate as much as his colleagues feared.

For high predictions of sea-level rise to be correct, “some big chunks of the Greenland ice sheet are going to have to melt, and they’re just not melting that way right now,” Dr. Christy said.

It's not clear exactly what Christy is saying is wrong - no numbers are attached. However, Christy generally thinks the IPCC overstates climate change. If the currently-observed rates cited in the article continue (no need for the pace to accelerate) then the IPCC has understated an impact from climate change. So Christy's bet should be that the current melting will decrease. Wonder if he'd put money on that.

More on Intrade and the skewed Climate Bet

(Original post here.  Summary:  people trying to criticize Al Gore set up a skewed bet against him on Intrade, which they are in the process of losing anyway.)

As current global temperatures continue being awful, the Intrade bet between exaggerated warming trends for a ridiculously short 3-year period and no warming clearly supports the high end warming at a 3:1 market ratio right now.  A while after my first post on this subject, I contacted Andreas Grafe, one of the people who set up the bet and who works with climate denialist Scott Armstrong.

To Grafe's credit, he did respond to my first email.  He says he never had an opinion on the climate issue and just wanted to set up a prediction market as part of his academic work on those markets.  He also points out that Armstrong would only expect a slightly greater than 50% chance of winning based on a short time frame, and mentions a longer ten-year time frame on an imaginary-money market (Hubdub) that has now shut down.

However.  No response to my pointing out that the IPCC didn't predict a short term rise of .03C/year in 1990, or the differences with modern IPCC predictions.  He did say that they wanted but couldn't get a ten year period from Intrade, but I think and said that a three year period is so short to be virtually useless.  Never heard back from my second email.

I'd hope that after the Climatebet crowing over "winning" the first 20 months of their bet, that Grafe would distance himself from their nonsense.  Maybe he did a little bit, but if he wants to help with useful prediction markets, he needs something better than this.

We have a record - hottest 12 months since modern record-keeping began in 1880

Via David Appell and this commenter, NASA records show the last 12 months, April 2009 to March 2010, to be the warmest 12 months since global records began, 130 years ago.

What is important about this record is how it fits a trend. It would be interesting but unimportant (kind of like the occasional record cold or snow we see in some locations are interesting but unimportant) except that it further confirms the long-running trend for warmth, and contradicts the denialist claims that temperatures have been cooling in recent years. I'm not sure if we need further confirmation of something like gravity, but it's been checked and it's still there. With Kerry and Graham set to unveil their new climate bill next week, I think it would be appropriate to make a big deal out of this.

The satellite sets don't yet show a record, but they measure slightly different things, and they're going up too. I wonder how long it will take people like Roy Spencer to continue reporting warming before they finally break down and admit what's happening. It would also be interesting to see what other surface record compilations give for their results on a running 12 month period.

Joe Romm has more about March temperatures at ClimateProgress.

UPDATE: Brad DeLong understands the value of emphasizing this record.

I wonder if I could work out a bet with James Hansen over cap and trade

In the very small category of people who have done a lot to help on climate change but have also damaged the cause, number one on the list has to go to James Hansen.  The help far outweighs the harm in his case (in contrast to the number two person, James Lovelock), but he's really being problematic with his opposition to even the squeaky-clean, cap-and-dividend bill in Congress, the one that I think has little chance of passing.  Check the link for Joe Romm's critique, which I think is accurate.  Hansen supports alternative legislation, a revenue-neutral carbon tax where the money is redistributed back on a per-capita basis except with limits to families with too many children, which I think is just great and that maybe 5 percent of the country at most would also agree that it's great.  Thanks for that practical suggestion.

So I don't have a specific bet in mind, I'm just thinking that if Hansen believes Cantwell-Collins will have "only a small impact on emissions" then the European Union's cap-and-trade must have a near-zero effect.  I think the EU scheme should do most of what it intended.  Maybe that's sufficient daylight between positions to set up a bet.

There's the issue of offsets that would complicate the bet.  If I buy solar panels on my roof to reduce emissions, that's great.  If my roof doesn't work and instead I buy solar panels for your roof, that's an evil evil offset (yes, I'm exaggerating, but I'm not sure it's by much).  I think though that even if we disallow offsets for wrong reasons, there's still a net reduction in cap-and-trade, so maybe some more research could give room for a bet.

Much better news about Hansen is this piece of info I didn't know - that he called present-day warming as happening as early as 1981 (not just a prediction of future warming).  Impressive.

Scott Armstrong losing the skewed bet his side set up at Intrade

(Greetings, Andrew Bolt readers!  Please let Andrew know that I'd love to bet him personally over global warming, and my bet offers are here.  I'd also happily bet him even odds over the Armstrong bet offer discussed below.  You might also be interested in a 2006 post I wrote on how to cook Andrew Bolt, as he now seems to be using the same excuse, arguing the current warming isn't part of a long term trend.)


The last we heard from climate denialist Scott Armstrong was several years ago when RealClimate took apart his convoluted offer to "bet" in some form against Al Gore over whether climate models were accurate, where the offer was only against certain fixed locations and while not allowing the climate models to operate properly.

Unfortunately for Armstrong, someone on his side of the fence took the denialism seriously and tried to apply it in a clear format.  Crandles alerted me to some climate- and weather-related predictions at the Intrade betting market (you have click on "Markets" and then click through the left-side menu), and one of them is somewhat inappropriately titled "Climate Change Prediction: Al Gore v Scott Armstrong. Armstrong to Win"


Details are at the "Contract Specific Rules".  Instead of the convoluted original bet, they simply want to compare 2007 to 2010.  A period that short throws a lot of random noise into the analysis, but that only slightly benefits someone who's making a bad prediction.  They've also selected UAH satellite data out of all the half-dozen possible surface and satellite datasets, the one that has shown the least amount of increase, another way to slightly skew the odds.

Most ridiculous though is how they make the comparative predictions for purposes of settling the bet, which is worth quoting:

• Armstrong forecasts no change in global mean temperature over the next ten years. He predicts the 2010 annual global mean temperature will be 0.284, the same as 2007.
• Gore has not made an official forecast. He did, however, imply that the global mean temperature would increase at a rapid rate - presumably at least as great as the IPCC's 1992 projection of 0.03°C-per-year. Therefore the IPCC's 1992 projection will to be taken as Gore's forecast. This forecast predicts the 2010 annual global mean temperature anomaly to be 0.374 (0.284+[3*0.03])

Really, Gore implied that?  A citation would be useful, especially one with a date attached.  Actually, two citations are needed since I don't think the IPCC made short-term predictions in 1992 or otherwise indicated the temperature rise would be stable over the next century.  In 2001, the IPCC predicted .15 to .2C rise in the first few decades, and in 2007 it predicted .2C in the first decades.  Armstrong supporters were either unaware of the subsequent 15 years of climatology, or they were purposefully trying to skew the bet - take your pick.

But the irony stems from 2010 shaping up to be a hot year so far even according to UAH, with both January and February over .6C above the the mean.  Armstrong fans lose if 2010 is above .328C.  Unsurprisingly, the bet last traded at 30, or more than 3:1 against Armstrong.  Funny how there are no updates at the denialist website since January data came online.

What would be far more interesting is an accurate Armstrong v. Gore bet, or maybe more appropriately titled Armstrong v. the IPCC.  Make it a ten year bet instead of the tiny, three-year period, and center it halfway between no warming and the IPCC prediction of .2C per decade.  With Armstrong in bad shape in the current unfair bet, his side should do even worse in a fair bet.  Might be worth suggesting to Intrade, though, as something that could accomplish the prediction that James Annan called for several years ago.

UPDATE:  March has come in even warmer, at .65C.  Armstrong's side is looking very embarrassed now.

UPDATE 2:  Intrade now bidding at 20, or 5:1 against Armstrong's side (UPDATE UPDATED:  per the comments, I screwed up the ratio which is actually 4:1 against at price of 20).  I think a more interesting prediction would be when the denialist website that focuses on this bet, quietly folds up shop.

Climate betting baseline set

The always-pleasant David Evans emailed me a little while back, reminding me that we now have the baseline measurement sent for our bet of $6,000 - $9,000 that temps will increase at reasonably rapid rate. The bet we made in 2007 was for the increase above the five-year GISS average for 2007, which wasn't established until the end of 2009. It's .55C above the 1951-1980 baseline, and the five years include the three highest temps in the 130-year GISS record. Nothing especially weird happened in those years - fairly typical/slightly warm from my perspective, and just what you'd expect prior to a slowdown in warming from David's perspective.

For those who haven't made it their business to memorize the bet details, they're here:

We have three bet periods -10, 15, and 20 years - and two bets for each period - an even-odds bet and a 2:1 bet in David's favor. The even-odds bet centers around a temperature increase rate of 0.15C/decade with a 0.02 void margin on either side (bet voids if temps increase between .13 and .17C/decade). The 2:1 bet centers on 0.1C/decade with a .01 void margin. Even-odds bets are for $1,000 each, and the 2:1 bets increase over time, with me betting $1,000, $2,000 and $3,000, and David betting half that. My exposure is $9,000; his is $6,000.

Temps from 2010 through 2014 won't directly affect who wins, although they'll give an increasingly good idea of who's likely to win (note though that because 2005 was the GISS record and included in the 2007 five-year average, the 2008 average will only be higher if 2010 is a new record). With the baseline established, our two bets each for 2017, 2022, and 2027 averages are centered at .6C and .7C above the 1951-1980 period for 2017; at .65C and .775C for 2022; lastly at .75C and .85C for 2027.

The other (and original) significant-money bet was between James Annan and two Russian cosmologists, where the Russians predict cooling. I thought I'd look at how it's going - a slightly different data set, 6-year average, baseline set at 1998-2003 and compared to 2012-2017. I'll just be lazy and compare to the 5-year GISS averages in the links above. 1998-2002 is .45C above baseline, and latest five-year average, 2005-2009, is .55C. For the Russians to win, they need temps to start declining soon, and fairly dramatically. James can start making plans for his $10,000, I think.

And there's William "Always the Bridesmaid, Never the Bride" Connolley who hasn't been able to arrange any big bets on warming. Lots of small ones though, including one against me for $10 that he won but I think he's forgotten about, and I'm not going to remind him.

I've had a couple of nibbles for bets, but nothing's worked out - I could probably try a little harder to make them work, and might try and revive some prospects.

Not much else on climate betting that I've heard. Nate at Fivethirtyeight.com wrote in favor of climate prediction market, and argued it's unlikely to be manipulated by people placing bad bets in order to support their political arguments. I agree, on the basis that it wouldn't take too much money against us to tap out me, William, and the few others who are out there taunting denialists to put their money where their mouths are, but no one's done it. Too bad.

UPDATE:  Crandles points out in the comments that he won $1300 betting on 2009 being one of the five warmest years at Intrade.  Some other interesting bet options there, maybe.....

The baseball stats wizard jumps into climate betting

Nate Silver of baseball and political statistics fame has a climate bet of sorts up. Sick of denialists who point to occasional cold weather in their hometown as a reason that warming isn't happening, Nate offers the following:

1. For each day that the high temperature in your hometown is at least 1 degree Fahrenheit above average, as listed by Weather Underground, you owe me $25. For each day that it is at least 1 degree Fahrenheit below average, I owe you $25.
2. The challenge proceeds in monthly intervals, with the first month being August. At the end of each month, we'll tally up the winning and losing days and the loser writes the winner a check for the balance.
3. The challenge automatically rolls over to the next month until/unless: (i) one party informs the other by the 20th of the previous month that he would like to discontinue the challenge (that is, if you want to discontinue the challenge for September, you'd have to tell me this by August 20th), or (ii) the losing party has failed to pay the winning party in a timely fashion, in which case the challenge may be canceled at the sole discretion of the winning party.

The two questions I have for climate bets I consider are 1. will winning the bet provide substantial evidence in support of the winner's position and against the loser's position; and 2. is my side likely to win. I'd say Nate's offer fails the first test and probably passes the second. Weather in any one location over a short period of several months tells you almost nothing about whether global climate change is real.

As to winning, Nate is betting current temps against historical average, and because the US has warmed from climate change, odds should be slightly in his favor. On the other hand, his potential betting opponents can look up long-term forecasts for their region. While not highly accurate, I'd guess a place with a forecasted cold autumn could go below average. But Nate's the stats wizard, not me, so I guess he thinks the odds are low, or he has already checked long-term forecasts for the entire US and thinks he's safe, especially since he's closing the bet period in two days.

All in all, an okay method he's using to shut down some stupidity, but not a bet I'd do myself.

Hey Sen. Inhofe, hire me to write your climate commentary!

Saw this Inhofe quote at Talking Points Memo:

'I look forward to a full, open and honest debate over the 600-plus page Waxman-Markey climate tax bill,' Senator Inhofe said. 'It appears that this legislation is yet another version of the same story: a job-killing tax increase on American consumers that jeopardizes America’s energy security, while doing nothing to address climate change. In short, it’s all economic pain for no climate gain.'

Considering that the bill's even stronger than Obama's position in the short term and calls for 80% reductions in 2050, I thought Inhofe's claim that it would do nothing was worth seeing in full.

I went to Inhofe's site for the full commentary, and the paragraph above was the full commentary.

Inhofe's new communications guy, Matt Dempsey, needs to step up his game. Here's the analytical paragraph I would add to support Inhofe's conclusory statement:

'I know that unless China and India both agree to a binding greenhouse gas reductions where they explicitly acknowledge that a Chinese person is one-third as worthy as an American, and an Indian one-tenth as worthy, then any reductions by the US will actually CAUSE increases by China and India,' Senator Inhofe said. 'I say this without any evidence to prove it, because my gut instinct is all I need and all I ever need. I also say this without any cynical intent to stop greenhouse gas regulation, despite the fact that I also claim to believe the whole thing is a hoax. And by the way, I refuse to put my money where my mouth is by betting over global warming.'

That's much better.

Mark Campbell gives 33% chance that IPCC is right, and no betting will happen

(UPDATE: some overlooked email correspondence going on now, I will repost later after it's resolved.)

I'm not sure how important it was to see if Naval Academy chemistry professor Mark Campbell would bet over his position. He only wrote one letter to the editor denying the mainstream consensus that I'm aware of, but it was a fairly aggressive one that was trumpeted by Marc Morano:

....If we are going to stoop to name-calling, an appropriate name for
people with the view The Baltimore Sun endorses could be "Chicken Littles." But
instead of claiming that the sky is falling, they claim the sky is burning....
To many of us, there is no convincing evidence that carbon dioxide produced by
humans has any influence on the Earth's climate. Arguing that our country should
decrease its use of fossil fuels is a laudable goal, but the reason to do so
should be to reduce our reliance on energy from foreign sources, not to reduce
the danger from some imaginary boogeyman.

In any event, Campbell is one of the few non-retired science professors who's willing to say this stuff, so I thought it worthwhile to contact him. He exceeded 95% of the denialists out there by responding to my email and actually exploring a bet, but unlike David Evans or Bill Gray, he never lost the aggressive tone. I wonder if that hostility has anything to do with being so catastrophically wrong.

Anyway, his first bet offer was fine - it was to take 1980-2000 warming and project the same amount for 2000-2020. If 2000-2020 meets or exceeds the 1980-2000 warming rate then I win, and if it's half or less of the 1980-2000 warming rate then he wins. The idea was fine but the data he used was wrong (he got it by eyeballing a graph), and when I supplied correct data he began backing away. Ultimately the only bet he would offer against the IPCC position had to favor him by 10:1 odds over a twenty-year period.

Seeing as I give 20:1 odds or better that the IPCC is right, 10:1 odds might sound fair, but the odds that the IPCC is right overall doesn't translate directly into the odds of the outcome for any particular period matching what the IPCC says. Also, I don't have the money to make my betting partner put out a significant bet if I have to bet ten times as much.

Here was my email to Campbell:

Mark,

I'm sorry you don't consider your own previous bet offers as fair ones.
The idea is that both sides perceive different odds of an event and can reach a
bet point where each side thinks it's likely to win.I believe there's been some
utility in this discussion in that you acknowledged to me at least a 33% chance
of the IPCC position being right (see update below). I think in any policy claims you make against controlling emissions, you might want to acknowledge that too, given the downside of what will happen if the IPCC is indeed right and we continue our path of doing very little to control emissions....The 4:1 bet offer you've made,
by the way, doesn't contradict the IPCC range because I can only win at a rate
significantly higher than the IPCC predicts for the next few decades. And
the Wrigley-Raper paper has been criticized as inappropriate melding of
different scenarios (as I recall, it was a long time ago).

Brian

I had also said I would only summarize but not quote him without permission. I just now discovered that he's misrepresented our negotiations, so I've reproduced the relevant correspondence, here.

I really expect better from someone lucky enough to teach at the Naval Academy.

Hoping for a bet with Mark Campbell (selected by Marc Morano)

Chemistry professor Mark Campbell was cited as not believing in anthropogenic climate change in the latest press dump by Marc Morano from Inhofe's office. I've just emailed a polite note to him to see if he's willing to bet over that position, and will definitely write it up if there's any interest.

Hat tip: Joe Romm, who refutes the other parts of Morano's press release.

UPDATE: we're negotiating, so we'll see if anything results.

Sea level rise - I'd love to bet over it

Thanks to Steve Bloom for pointing towards a rather confident "skeptic" claiming he wants to bet over sea level rise for the next five years. Digging through we get this:

Pierre Gosselin (08:35:38) :

And what the heck,
I just e-mailed the following to MS EILPERIN:

———
Dear Ms Eilperin,
- Al Gore says: 20 ft sea level rise in about 100 years (i.e. 12 inches every 5 years).
- Prof Stefan Ramstorf (sic) of the Potsdamer Institute in Germany says: 4ft 8in by 2100. (i.e. 2.5 inches every 5 years).

I say that the average annual sea level will not increase more than 1.25 inches in the next 5 years. Far below what you and the two above mentioned gentlemen are warning.

So, being the generous guy I am, I’m asking you to bet $1,500.00. If the average sea level is more than 1.25″ higher in 5 years (2013) than it is in 2008, then I’ll pay you $1500. If it is less, then you pay me $1500.

What are you waiting for? The overwhelming consensus says you will win the bet!
———————-

Anyone think she’ll respond?
Bet she doesn’t.

Gore said nothing of the sort, first of all. I watched the movie and have the book, no time frame for the 20 foot rise was given, but it is right in the long run. (I have, fwiw, mildly criticized Gore's omission of a time frame.)

Rahmstorf also didn't say 1.2 meters by 2100, he said between .5 and 1.2 meters by 2100. Gosselin's proposed bet "against" Rahmstorf's position actually works out to be .6 meters, so Gosselin would win even if Rahmstorf had been proven right. Gosselin's bet is even worse though, because the predictions assume that the rise would accelerate later in the century with increased warming, while Gosselin simply allocates the entire warming proportionately, an equal amount each year.

So what's a fair bet? From the viewpoint of those who are under the impression that temperatures have fallen over the last 11 years, I would guess they anticipate random change in sea level over the next five years. From a position based in reality, which is this:


I'd expect the current rate of 3.1mm/yr to continue (not much acceleration should be noticeable in just five years). Half way between delusion and reality is 1.55 mm/yr for five years, and that should be a fair bet. Of course, temperatures haven't really fallen in the last 11 years, but that's what the other side wants to argue.

I could lose this bet simply due to random noise, but it's unlikely. I'll add it to my list of proposed bets, and we'll see if Gosselin or anyone else is interested.

For some more info on sea level rise, see Deltoid.

UPDATE: edited for politeness.

I've created a monster (but he's a nice monster)

David Evans didn't have much of a public profile until he and I arranged a bet over future warming.

What I didn't anticipate is the denialist response to the bet, which I'd summarize as "OMG OMG OMG! A vanishingly small BUT NON-ZERO percentage of skeptics are actually willing to put their money where their mouths are, therefore the skeptic position is right!" This ignores the issue that it's the result of the bet that will provide the most evidence as to who's right, not to mention the extremely large number of denialists who wouldn't and still won't bet.

Still, the denialist fan reaction has given David some prominence, most recently in The Australian, which is some ridiculous Australian paper that's been on a denialist tear. I don't know what to do about it, frankly. I guess there isn't much I can do about it now- the bet's been made. The one thing I can do is link to Tim Lambert's definitive rebuttal to David's piece. And to James Annan's rebuttal of David's original argument.

I latched on the betting idea as a good way to communicate how wrong and often insincere the denialists are. I still think it is, but the occasional sincere skeptic is seized on by the denialists to set back the cause of reason.

And none of this is to deny the fact that David Evans is a nice guy. I can attest from numerous emails and one phone conversation that he's polite and reasonable in all respects other than his analysis of climate science. David's reference to himself as a "rocket scientist" is tongue-in-cheek although that might be missed by the denialist field. I just hope he doesn't go too far down this path.

The one good thing is that while it take many years to settle our bet, it won't take long to see who's on the path to winning, and that's likely to be helpful. Also: David said in his own post about this issue that "Given that betting is thus possible on this issue, it seems strange that some people who take strong positions and profit by those positions are not prepared to bet even a small amount of their own money. Betting something of one's own money adds, shall we say, credibility." People who support David's position should contact me about getting into the game.

UPDATE: David responds in the comments.

Climate bet proposal for Bill Gray in the Rocky Mountain Chronicle

Nice writeup of the bet status and the purpose of climate betting here. The Chronicle is the weekly newspaper in Bill Gray's hometown, Fort Collins.

And just in time to screw up a ten-year bet designed to test the difference between anthropic warming and natural variability is a prediction issued today that a naturally variable cooling cycle will be so strong in the next ten years that it will temporarily mask the anthropic warming signal. Unlike Gray's assertion, this is a scientifically-based prediction, but it's just a single one. I'd like to see what the rest of the scientific community thinks of it.

UPDATES: When I talked to the reporter, he referred to the bet offer as an "old school" way of settling differences. I liked that description, and was sorry it didn't get into the article.

As to my increased respect for skeptics who put their money where their mouths are, that respect is for them as persons. It doesn't make their theories any better.

I should clarify that despite this new prediction of masked temps, I'm not backing off from the bet terms with Gray. I will modify future bet offers if this prediction solidifies into the consensus position, but backing out of the current negotiation wouldn't be old school.

Well I'll be .... Bill Gray says he wants to bet

I received a very polite email today from Bill Gray, saying he just learned of my bet "offer" (actually it's his offer that I accepted, but close enough) and is interested in making the bet, for charity. He's traveling but will get back to me with potential terms before mid-May.

I'm kind of surprised, but assuming he offers reasonable terms, then a climate crisis charity is going to have a decent chunk of money coming their way. And as for Dr. Gray, betting is a helpful way to distinguish skeptics from the sleaziest denialists, so good for him (assuming the bet happens).

I think that some denialists seized on my bet with David Evans as if it were some kind of victory that a skeptic was actually willing to put his money where his mouth was. I hope we can avoid a similar problem here by challenging other denialists to make this same bet. For folks on our side, betting against the position that temperatures would actually fall should be pretty attractive to people who support the mainstream consensus.

I accept Bill Gray's climate bet offer - will he seal the deal?

Bill Gray went a step beyond his usual denialist statements last month at the Heartland Institute "conference" on climate change:

“We should begin to see cooling coming on,” Gray said. “I’m willing to make a big financial bet on it. In 10 years, I expect the globe to be somewhat cooler than it is now, because this ocean effect will dominate over the human-induced CO₂ effect and I believe the solar effect and the land-use effect. I think this is likely bigger.”

(audio clip at the link above.)

In late 2005, Gray had refused to bet me among other people, so this was an interesting development. (Also interesting that in 2005, Gray was saying cooling would happen between 2010 in 2013, and now he moves the goalposts further down the field.)

I decided to make it more interesting, and placed the following ad last Friday on page 6 of The Collegian, the student newspaper at Colorado State University where Gray is apparently still active:

An Open Letter to Dr. Bill Gray,
Professor Emeritus, Colorado State University

Dear Dr. Bill Gray:

You deny that Earth will continue warming. Two years ago, you told me that you weren’t interested in betting over whether you’re right. Now you’ve said

“We should begin to see cooling coming on……. I’m willing to make a big financial bet on it. In 10 years, I expect the globe to be somewhat cooler than it is now .”

That’s wonderful – Dr. Gray, I gladly accept your offer to bet over global warming.

I suggest we each donate $5,000 to the Longbets.org charity to bet over whether temperatures will rise or fall in ten years. When the time’s up, Longbets will give all of our money to the winner’s designated charity, even if neither of us is around to see who’s won.

You could designate our $10,000 plus interest to go to CSU. If I win, our combined money will go to an appropriate “climate crisis” charity.

I will contact you within the next two weeks to finalize our agreement, and you can also reach me at : schmidtb98@yahoo.com, or http://www.backseatdriving.blogspot.com.

When so many climate skeptics have refused to bet over their beliefs (among them James Inhofe, Marc Morano, Bob Carter, Tim Ball, Chris Monckton, and the list goes on), it’s refreshing that you’re willing to put your money where your mouth is.

Thank you again for making this offer.

Sincerely,
Brian Schmidt

Unfortunately, The Collegian doesn't put the print ads on its website, but anyone who can get the paper copy will find the ad on page 6 from April 11, 2008 (or I can email whoever wants the pdf of that page of the paper).

So we'll see if Gray is really willing to make his "large financial bet," and I'll certainly consider different ways to bet if that interests him.

Betting, by the way, is my response to the great "should we respond to denialists or ignore them" debate. The most strongly consensus-contradicting denialist claim becomes all the more reason the denialist should take my money away from me. The fact that all the loudest denialists aren't interested in doing so is an effective tool to contradict them (I hope).

Placing this print ad also has one other potential benefit - denialist editors on wikipedia are censoring biographical articles about Gray and others that mention their refusal to bet, because the documentation of the bets are on blogs, which Wikipedia frowns on. This stuff is now in print, both against Gray and the whole string of others that I mentioned. Maybe it'll finally get reported in wiki.

(Hat tip to Winnebago for letting me know about Gray's offer.)

Light blogging this week - climate betting next week?

I'm travelling and won't be blogging until sometime next week. I may have a development on the climate betting front by then, and will be sure to post when that happens.

Meanwhile, I recommend taking a look at James' post on the Intrade prediction market for a near-record temperature in 2008. From James' analysis, it sounds like the 20% odds are high. I think it would be interesting though to calculate the odds if temperature changes were random instead of forced, and that would indicate something about this market's belief in global warming.

Also on betting, I agree with William that a climate change bet where all the money goes to the same charity no matter who wins isn't much of a bet. However, a bet where the money goes to different charities depending on who wins is a different matter, especially if the charities work to cross purposes, like a climate-crisis charity versus a right-wing denialist think tank.

UPDATE: fixed the mistake in the post title - I knew what I meant to say!