Steve McIntyre has been playing a fun sort of “degrees of separation” game, identifying members of climate science’s “hockey team” based on coauthorship of paleoclimate papers and using their team membership to disparage their work. I’ve not found it to be a particularly useful or persuasive argument, and Tim Lambert has pointed out the inconsistency with which McIntyre applies it.

But I’ve always been fascinated with the whole Erdös/Kevin Bacon degrees of separation thing. So for a lunchtime exercise, I thought I’d see the shortest path I could find between McIntyre and Michael Mann, the two main characters of climate science’s long-running soap opera.

There’s only one rule in my game: No use of IPCC chapter co-authorship.*

Herewith, then, are the eight degrees of separation between Steve McIntyre and Mike Mann:

1. In 2005, Steve McIntyre and Ross McKitrick published “Hockey sticks, principal components and spurious significance” in GRL
2. McKitrick and Pat Michaels have worked together on several projects. We’ll go here with their 2004 “A test of corrections for extraneous signals in gridded surface temperature data.”
3. In 2003, Michaels and John Christy were among the coauthors of a “Test for harmful collinearity among predictor variables used in modeling global temperature.”
4. Last year, Christy and Roger Pielke Sr. wrote a critique of a paper in Science by Jim Hansen.
5. In 2004, Pielke Sr. and Craig Allen were coauthors of a really interesting PNAS paper entitled “Cross-scale interactions, nonlinearities, and forecasting catastrophic events.” (In fact, rather than wasting your time on all this hockey stick war stuff, I suggest you go read this paper.)
6. In 1999, Allen, Tom Swetnam and Julio Betancourt wrote “Applied Historical Ecology: Using the Past to Manage for the Future” in Ecological Applications. (Julio’s not technically necessary for this list, except that a) he’s one of the most interesting scientists I’ve had the pleasure to know, and b) it’s because of him that I knew enough about these fields to find a path through the literature.)
7. It would be remarkable to not find a Swetnam-Malcolm Hughes link. I was sitting in Tom’s office a couple of summers ago interviewing him about tree rings and drought and he asked, “Are you going to talk to Malcolm? You must talk to Malcolm,” and took me upstairs and introduced us. I guess I’ll go with Hughes/Swetnam/Diaz – “Tree Rings and Climate: Sharpening the Focus,” published in EOS in 2004.
8. Which brings us, of course, to Mann, Bradley and Hughes, co-authors in 1998 of “Global-Scale Temperature Patterns and Climate Forcing Over the Past Six Centuries”.

* I made up this rule ex post facto, because it made it too easy. Mann and Christy were co-authors of Chapter 2 in the last IPCC report, which short-circuits a whole bunch of interesting people. What can I say? It’s my game, I get to make up the rules.

update: In the comments I detail the discovery of a five-degree chain between M and M. For the first person to beat that (without using the IPCC chapter), I’ll buy a beverage of your choice the next time we happen to be in the same city at the same time.

Bonus points for anyone who can make a chain of any length linking William Connolley and Luboš Motl .

In keeping with Kevin Vranes’ dictum that “it’s up to the bloggers to highlight the papers that didn’t make Science, Nature, JAMA or NEJM” because those half-wits in the mainstream media won’t, here’s an interesting paper on climate variability and food in Africa.

Leif Christian Stige of the University of Oslo and colleagues used crop production records and satellite data to conclude that reduced food production during El Niño years in Africa is the equivalent of “the nutritional requirements of (approximately) 20 million people”. Yowza. Kinda puts our worries about the New Mexico ski season this year into perspective. The big loser is corn in southern Africa, something documented a dozen years ago by Mark Cane. So the broad story here is already well known. It’s the 20 million number that jumped out at me.

Stige et al. spin a global warming tale to go along with this:

Results suggest reduced African food production if the global climate changes toward more El Niño-like conditions, as most climate models predict.

As I’ve written before, I don’t think the science is there to head very far down the global warming->El Niño path. But regardless of those details, there’s something we clearly do know about drought variability in Africa and elsewhere. Regardless of the imprint left by anthropogenic climate change, we know there is drought variability – wet times and dry times and then wet again and then dry again.

The real damage (see here for a longer discussion of this) happens when people don’t pay attention during the wet times to the fact that it’ll get dry soon enough. I recently read a great book chapter by Mickey Glantz entitled “drought follows the plow” (apparently there’s a whole book) that discusses what happened in the Sahel beginning in the late 1960s. Glantz argues that people moved north into the southern edge of the Sahara during the unusually wet 1950s and ’60s. When the pendulum swung back to dry in 1968, they were screwed.

It’s not unlike people building growing cities in the paths of hurricanes, and then being surprised when the waves wash over them. Climate change may be one variable here, and is clearly worth paying attention to, but changing societal vulnerability dominates the risk.

Some stuff I wrote elsewhere on how dry it is (sub. req.):

If we don’t get any rain in the next week— a good bet— the past four months will go into the record books as the driest winter in Albuquerque history.

With 0.14 inches since Nov. 1, Albuquerque is on the verge of shattering the old November-February record of 0.30 inches in the winter of 1903-04, according to Deirdre Kann of the National Weather Service.

A huge hat tip to Deirdre and Chuck Jones at the Weather Service for digging through the old data for me.

OK, if you smarty-pants scientists wanna do something useful with your time, here’s what I need to know. What effect will global warming have on my allergies?