Tuesday, September 02, 2008

Climate forecast: Germany

"In keinem anderem Land der Welt liegt bis dato eine präzisere Kalkulation der Klimafolgen vor. Sie soll die Grundlage für politische Planungen bilden." ("In no other country of the world do such precise calculations exist regarding the effects of climate change. They should serve as the basis for political planning.") That's what it says in Regierungsprognose enthüllt Folgen des Klimawandels für Deutschland in Der Spiegel for September 2, 2008 (you can read the entire report, too).

Now I'm mindful that I've recently written about the dangers of forecasting. Jay Forrest has reminded me of limitations to my claim; taken to extremes, it might suggest we can't usefully predict the rising of the sun in the morning or the need to buy food at the store (or grow it in the earth). I certainly don't mean to take it that far, and I'll write more about those limits someday.

Without having read the full report (it's 159 pages, after all), I suspect that this report can be useful if viewed at least like a scenario planning exercise: what could happen? How much in advance do we need to prepare? What are the triggers that would indicate it is time to prepare? If the time to start preparing is in the past, can we make strides in that direction without compromising our ability to deal with other futures, too? In other words, can we create robust plans for the future?

Or perhaps it's more accurate than that. I'd welcome ideas from people who have read it and have particular insights: what did you expect? What did you find? Were there any surprises? Does it seem credible?

And where are the rest of us in thinking about changes we'll face?

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Blogger Ralf Lippold said...

Sounds like the typical German sense of acurracy;-)

Changing the mental model that things will change and -by the way that is more than true- people, as well (over time).

Didn't know about the study. How many Germans will know and care about it (as nothing apperently changes at all, doesn't it?).


Ralf (Leipzig, Germany)

21 September, 2008 12:38  
Blogger Bill Harris said...

Ralf, thanks for the comment.

I'm currently reading the second edition of Art Kleiner's The Age of Heretics (I'll review it here when I'm finished), and it's interesting to compare this to the way scenario planning was used at Shell in the early 1970s. In a key presentation of six scenarios to Shell executives, someone asked which was the most probable. Pierre Wack refused to respond. He wanted people to consider their potential reactions to all of them.

22 September, 2008 06:55  
Blogger Tom Fiddaman said...

If this were in English, I'd note that they said "precise," not "accurate." Climate and integrated assessment models provide lots of precision, but very limited accuracy. Energy price forecasts are terrible, though emissions forecasts haven't been too bad. Emissions uncertainty merges with big uncertainties in the carbon cycle (temperature feedback), climate (sensitivity), and impacts (regional downscaling and adaptation). The question marks downstream make the impact of a given emissions trajectory highly uncertain.

That's not to say that models are useless; quite the contrary. They're extremely helpful for thinking about the problem. In many cases, granularity is useful: the sum of a lot of local impacts can be rather different from a single aggregate value, for example. But one must remember that granularity is to some extent false precision, awash in a sea of noise, and seek robust strategies. Unfortunately, touting the precision of models instead leads people to think about one thing that might happen, and react to that. It also gets the modeler in trouble down the road, when the forecast doesn't come true.

26 September, 2008 14:25  

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