The Precautionary Principle in Atlanta, Georgia

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:

• Now I’m no fan of the precautionary principle, but...
• I am not a fan of the precautionary principle when applied to complex environmental problems such as climate change
• My argument is that the level of uncertainty is too great for a pdf of climate outcomes to be useful in the context of the precautionary principle.

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:

• However, the precautionary principle demands that we not take any risks here, and hence the IPCC should be put down

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.