Friday, January 31, 2014

The Precautionary Principle in Atlanta, Georgia

Sou | 10:27 PM Go to the first of 14 comments. Add a comment

By now many people will have heard of the snow in Atlanta this week, which brought the city to a messy standstill.  My sympathies to anyone caught up in it.

Source:  motorauthority.com via NBC Charlotte @wcnc

The main problem by various accounts was that none of the authorities took action in advance of the storm.  I say a storm, but I gather it was only a couple of inches of snow, which melted then froze on the roads - making driving a tad tricky for people not prepared for iced roads.

It appears that what happened was that ahead of the event, there were no requests for people to stay home. When the storm hit, lots of people tried to go home and got stranded on the roads.  Children were stranded at school overnight. Road maintenance people couldn't get onto the roads to salt them or whatever they might have done if they didn't have salt handy, because they were gridlocked with cars.  The end result was general chaos plus a bit of the blame game.

Judith Curry has an article about the storm (archived here).  According to her accounts, the weather bureaux gave the odds at 30% that the snow would hit Atlanta.  I gather that she and most of the people commenting there agree that even though the odds were less than one in three, the powers that be should have adopted the precautionary principle.  Judith wrote:
Ah . . . so the kind of risk management that elected officials are good at is political risk management.  What are the political downsides of making proactive decisions, and then the weather event fails to materialize?  Two such examples come immediately to my mind:
  • Does anyone recall the pre-emptive closing of federal offices in Washington DC last April, owing to a forecast of snow?  I remember this, since I was in DC for congressional testimony (a tweet at 2 a.m. told me the Hearing was cancelled).  Well, it rained in DC (didn’t snow).  A bunch of flights into and out of DC were cancelled (including mine), but other than that I think the consequences of this pre-emptive closing were pretty minor, and that the right call was made by the government officials.
  • Another example with a more complex outcome was the evacuation of Houston in 2005 in anticipation of Hurricane Rita.  Following on the heels of Hurricane Katrina, sensitivity was high.  Rita weakened and turned north, having almost no impact on Houston. Several people died in evacuation traffic accidents.

When the consequences of not acting are worse than the downsides of acting, it makes sense to act. However Judith has in the past said:

On the other hand, like with the 30% chance of snow in Atlanta, or when it otherwise suits her she goes for it. For example - from Judith's attachment that John Christy submitted to a House Committee hearing:

Now it's a dead cert that bad things will happen to good, bad and indifferent people alike if we don't make enough progress in cutting CO2 emissions (using the HotWhopper probability scale, dead cert means >99% likelihood!). And given that some of those bad things are likely to be very, very bad for a lot of people, the precautionary principle makes sense, regardless of modalities and uncertainties and whether or not the IPCC is put down.  (Putting down the IPCC won't stop the climate from changing.  All it will do is make it a bit harder for people to keep up with climate science, with the impacts, with how people are adapting to it and with what societies are doing to mitigate climate change.)

HotWhopper gets its odds from the IPCC and the science.  For example, from the AR5 WG1 Summary for Policy Makers:
Limiting the warming caused by anthropogenic CO2 emissions alone with a probability of  >33%, >50%, and >66% to less than 2°C since the period 1861–1880, will require cumulative CO2 emissions from all anthropogenic sources to stay between 0 and about 1560 GtC, 0 and about 1210 GtC, and 0 and about 1000 GtC since that period respectively. These upper amounts are reduced to about 880 GtC, 840 GtC, and 800 GtC respectively, when accounting for non-CO2 forcings as in RCP2.6. An amount of 531 [446 to 616] GtC, was already emitted by 2011. {12.5}

Combine that with what a two degree or hotter world will be like and it makes a lot of sense to reduce emissions.  Since the longer we leave it the bigger the cut will need to be, it also makes sense to start switching in earnest sooner rather than later. At least to create an environment that encourages the shift to clean energy.  At the very least to remove barriers to shifting to clean energy.

On the HotWhopper scale of no cert to dead cert, the dead cert of bad things happening if we don't cut CO2 emissions is a far surer bet than the chance of a snow storm in Atlanta.  Thing is, I expect a lot of people find it more pleasant to take a day or two off work (providing they still get paid) than finding out that their electricity comes from geothermal power or wind power or solar power. The latter notion makes some people go bananas.  "What?" they shriek. "You mean this electricity didn't come from black-lunged paupers taking the tops off mountains?" They cry. "It's a travesty! What is the world coming to!"

Exploring the mind of a climate science denier is fruitless.  Nut-full and fruitless.

PS From now on I'll be allowed to do what I've been doing - cite the IPCC report and quote from it.  The final version is up on the website.  H/t Stoat - who has been having fun trawling through the comments to it and the IPCC responses.


  1. She needs the 900 hPa Sandy on her Georgia state. Would love to see her caught out in that. That's all the diplomacy I can muster for this particular fraud.

  2. "Judith Curry has an article about the storm (archived here). According to her accounts, the weather bureaux gave the odds at 30% "

    'You were warned!' Al Roker and National Weather Service hit back at politicians blaming bad forecasts

    Read more: http://www.dailymail.co.uk/news/article-2548526/You-know-angry-people-Backlash-begins-Atlanta-mayor-attacked-live-air-REPORTER-response-ice-chaos-crippling-South.html#ixzz2s0PQJUck

  3. I'd be curious to know, what were the forecasts, really? Given Curry's well-established record of not doing her homework I won't buy her 30% figure unless there's independent confirmation.

    Is there an archive of old forecasts somewhere?

    1. Don, that was me being a bit sloppy, not Judith. Sorry about that. It wasn't central to my discussion.

      The 30% number came from a quote that Judith wrote from an article by Bryan Norcross at wunderground.com. Judith quoted a longer passage but this is the bit that I got the number from:

      "This is distressingly similar to Hurricane Sandy, of course. A major city, along with the state in this case, in spite of direct communications with the National Weather Service, is unable to put the pieces together to understand the RISK to their citizens. Risk implies uncertainty, and understanding it is at the heart of decision-making. Let’s say the chance of the storm producing 3 inches of snow was 30% on Monday, which sounds about right. The Georgia decision-makers didn’t understand that a 30% risk of a cataclysm requires major affirmative action. You can’t wait for a guarantee.

      "How about a 20% chance of tens of thousand of people being stranded on the highway in freezing temperatures? Is that enough for a governor or mayor to make the decision to tell people to stay home? It’s not easy, but it’s not rocket science. Mostly, you have to understand the ingredients that have to come together to create a disaster in your city. (See formula above.)"

      You can read Bryan Norcross' article here:


  4. The problem in Atlanta was the freezing rain which is very difficult to quantify.... In the NE, everyone knows better than to try and drive in those conditions...

  5. You would think with all her concern about "uncertainty" that Judith Curry would have been pressing Congress hard for additional funding for climate research, for more comprehensive observation networks and improved modeling capacity to reduce some of that "uncertainty."

  6. Regarding the comments to the IPCC via Stoat, I had a good laugh at Vincent Gray's comments. He must have been drunk and in a real fury when he wrote them. Couldn't even spell properly. You can just imagine every time he walks outside and looks at the clouds he shakes his fist while yelling 'Damn those climate models, it's the clouds I tells ya.'

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  7. electricity from geothermal power or wind power or solar power. The ... notion makes some people go bananas.

    How much geothermal energy is being generated at the moment? And what about the cost of overcoming the intermittency of wind? How much solar power is produced in Atlanta at the moment?

    Renewables are expensive and limited, that's why it still only produces a fraction of capacity, why there remains a massive block to their widespread use.

    Failing to acknowledge the whole argument, cherry-picking the sugar-coating and ignoring the downsides, is engaging in denial and disinformation.

    1. funny, I live in VT and just looked at installing solar. It looks like it would take a little over 10 years to cover the costs, but much of that is because of the expense of getting the conduit to my electrical board.
      I wonder what the cost will be in 5 year.
      In case you don't know VT is not the ideal location for solar>
      I am pretty sure 50 years from now young people are going to think it was crazy how long it took to switch from fossil fuels

    2. Tony, the economics of domestic solar PV are more complex than that. Basically it looks reasonable to you now because you are not factoring the cost of maintaining the grid connection to your home. Try calculating the cost of solar (including batteries, gas for cooking, etc.) if you disconnect entirely from the grid. You will find out how much it would really cost to reduce emissions with large-scale solar PV.

      In 50 years, young people would wonder why so many were unable to make simple calculations of energy payback. The might also wonder why we were so afraid of nuclear fission.

    3. Tony, you may find this website useful for working out how much you can generate. It started in Australia but now has data from home installations around the world. All user input.


      (We've been fortunate in timing the installation right. We have pretty well paid off our system and now getting electricity for free - actually making a small profit because of a generous feed-in tariff. Of course it cost a lot more to install back when we did it.)

  8. The Weather Channel had a lot of coverage of Atlanta's plight. I background-followed a lot of it, but only once, at the end, heard mention (other than the heavy traffic) of how freezing rain might cripple the freeways. Atlanta has a lot of hills.

  9. Great post Sou! A great unmasking of Curry.


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