Sunday, December 22, 2013

Quantifying some of the deaths from sea level rise

The Gort comment thread produced this at one point:

No one can seem to point to any real harm [from climate change], certainly not currently.
So that's silly, as well as completely missing the point that you can attribute events to climate change if you conduct the thought experiment of removing all the increased greenhouse gases and ocean heat. It also shows the real motivation for lukewarmers tricking themselves on the issue of attributing severe events - they think that if you can't attribute any one injury with certainty to climate change, then no one anywhere has been injured by climate change.

A general solution to this is to educate people about statistics and probability, but a more specific response might be to look at the 6000-plus deaths from Typhoon Haiyan. Wiki says most of the damage and loss of life was from a storm surge of up to 19 feet. In that part of the world, sea level rise to date is even worse than normal. Let's say it's one foot, although you could plug in another number.

Now depending on how good the original data was or how well it could be reconstructed, you could figure out the death rate in an area at a certain level above sea level that was hit by a surge, compare it to death rates a foot higher and a foot lower in sea level and figure out the incremental mortality from sea level rise. For example an area 16 feet above sea level with a 19 foot surge might experiences one death while a similarly-dense bordering area 15 feet above sea level experiences 10 deaths, 14 feet elevation 30 deaths, and 13 feet with 60 deaths. Sea level rise is responsible for 9 deaths at 15 feet, 20 deaths at 14 feet, and 30 deaths at 13 feet. You could do the same calculation with property damage. My guess is the numbers keep going up until you reach areas where everything was flattened.

For people, an additional complication is that many evacuated, so the actual population density when the storm hit probably wasn't what a survey showed in normal times. Maybe you can account for this. I'd guess though that the lowest areas were the most likely to evacuate, so not accounting for evacuations would underestimate the effect of sea level rise.

And Haiyan was just one event.

17 comments:

William Connolley said...

Your title was "Quantifying some of the deaths from sea level rise", but you haven't done that. You've just made some guesses.

But laying that aside, the obvious counter is: suppose you want to prevent these deaths, what is the best method? How would "not emitting CO2 equivalent to one foot of SLR" compare to other uses of the same resources - anything: building concrete shelters, early warning networks, whatever.

What I'm trying to say is that if you're setting out to use words like "quantifying" then you need to be thinking in this direction, unless cost-benefit is for some reason forbidden, of course.

Tom Curtis said...

Brian, it has already been partially done by DARA. Partially in that they include deaths from storm surge among deaths from Storms in general, listed as 2,500 per year in 2010, but only a confidence level "speculative". They separately list a current economic cost from sea level rise of 85 billion US dollars per annum (confidence: robust).

Overall, they list 400,000 deaths annually from global warming at current levels. That is significantly greater than the 140,000 per annum listed by the World Health Organization. Direct comparison of the two reports, however, shows that by category, DARA is more conservative than WHO, and that their greater number of deaths is because they include more proximate causes in the calculation, particularly deaths due to hunger.

Interesting in combating a common denier meme is the 35,000 net, deaths from Heat & Cold Illnesses. That figure includes 10,000 lives saved per annum in developed countries, and 45,000 excess deaths in developing countries.

Unfortunately for your purposes, these are statistical deaths, or more accurately, the deaths are real, but the ascription to an ultimate cause is based on statistical analysis.

With regard to the stoats comments, my understanding is that your question is whether or not their exist reasonably demonstrable deaths, whose ultimate cause is sea level rise rather than what is the best policy to pursue to prevent such deaths in the future. His suggestion is valid in response to the second question, not the first. That is, there are in fact currently deaths as a result of global warming and sea level rise. That those deaths exist is reasonably demonstrable on a statistical basis. Further, the "statistical" deaths due to global warming and sea level rise exceed the "statistical" lives saved due to the same factors. None of this, however, determines whether the more appropriate response either global warming or sea level rise is mitigation, or adaption, or some combination.

Tom Curtis said...

A small clarification re statistical deaths. In fact the deaths are statistical in two ways - first these are average annual proportions applied to the trend death rate in 2010; and the ascription of ultimate cause is based on statistical analysis. That does not change the fact that real deaths are occurring as a result of global warming. It just limits our ability to identify them.

Brian said...

Tom/William: I can't get the DARA doc to upload but will keep trying. My guess is the real killer from climate change is a slight uptick in infant mortality among subsistence farmers due to worse crop harvests due to changing rainfall. Trying to reasonably demonstrate and identify those thousands of dead children among the millions that die anyway is very difficult though. I went for an easier possibility.

And I suppose I could've titled it "On the subject of quantifying some of the deaths from sea level rise" but I don't think I'm too far off. Yes, I obviously haven't even come close to actually doing the work (nor am I qualified to do it). I don't know if anyone could ever get the necessary data (maybe via surveys?), although I'd guess that property damage would be easier to figure out.

Coal pollution is kind of a parallel case: a better health system could have reduced the asthma death rate, but it feels to me that that primary responsibility lies with the coal industry in triggering the asthma. Maybe in the future it could theoretically make more sense to adapt to coal particulate emissions rather than mitigate them down, but I still give responsibility for past deaths to coal.

Tom Curtis said...

Brian, your guess is pretty good. Of 400,000 global related deaths, DARA attributes 225,000 to hunger, of which half are children under five. The next largest killer are diarrhea related deaths (85,000), heat (35,000) meningitis (30,000), and malaria and communicable diseases (20,000). WHO says that 85% of global warming related deaths are of children, but does not analyse hunger, heat, or meningitis. I note from their summary statistics (not PDF) DARA attribute 80% of deaths to children under 5. I assume their 350,000 compared to my 400,000 is because they do not include deaths whose confidence is speculative, or weight deaths. The 400,000 was from adding up all climate related deaths from their report on a spread sheet.

One thing that will become apparent once you download the full report is how much poverty contributes to vulnerability to climate change. In the short term, poverty alleviation would be the best means to combat climate change. Unfortunately, that is not the case in the medium to long term.

William Connolley said...

I, too, can't get the DARA doc to upload. But I found http://www.wfp.org/hunger/stats

Its all a bit bitesize, but it says:

1. 842 million people in the world do not have enough to eat. This number has fallen by 156 million since 1990.

10. WFP calculates that US$3.2 billion is needed per year to reach all 66 million hungry school-age children.

So would that $3.2bn save all the children dying from hunger, and not just the (small? - no-one has yet quantified it) increment from GW? In which case, would it be a better deal - if we were mainly concerned with saving people?

Again, I'm not seeing any attempt at cost-benefit In the world of crap politics we inhabit, that's no bar to your voice being heard; in any sane world, it would be.

Anonymous said...

That old coot that didn't leave Mount Saint Helens didn't die because
the eruption was stronger or weaker than normal, he died because he didn't leave.

Sadly, many in Haiyan's path didn't understand what 'storm surge' was -
tsunami, though inaccurate, was a more meaningful term.

WHENEVER a typhoon strikes, the response is to evacuate - the few inches that sea level
has risen are irrelevant.

Anonymous said...

What nonsense you hysterics spout.


Significantly more people die in WINTER!
Significantly fewer people die during SUMMER!

There are obviously lots of factors,
but numerous deadly digestive and respiratory diseases are
heat limited.


Global warming is saving lives?

Anonymous said...

"1. 842 million people in the world do not have enough to eat. This number has fallen by 156 million since 1990."

So instead of asking what percentage of those are suffering because of war and socialist dictatorships, you wanna cling to some emotional attachment to the 'global warming - bad' meme?

Children starving in North Korea or the Congo have real worries
and they don't have anything to do with a bunch of religious replacement
superstitions.

Anonymous said...

"Wiki says most of the damage and loss of life was from a storm surge of up to 19 feet."

So, let me understand - you're saying people evacuated up to 18 feet, but because sea level is a foot higher, they died there?

Oh. Now I understand.

Brian said...

Last anon - you're embarassing yourself. Probably just as well you didn't give yourself a name.

Tom Curtis said...

William Connolley, "I have not read the quantification" does not equal "no one has yet quantified it". The DARA CVM2 notes that deaths due to hunger attributable to global warming represent just 5% of all deaths due to hunger. That figure is consistent with the 3.9 million deaths attributed by WHO to child hood underweight, nutritional deficiency, or insufficient breast milk in its assessment of global risk factors.

Further, nobody here is arguing for tackling global warming instead of tackling global hunger. Are you arguing that spending that spending the 0.45% of GWP necessary to end hunger will prevent placing a price on carbon? If not, I do not see your point.

Tom Curtis said...

Annonymous @2:44pm, let me repeat, and considering deaths directly due to heat/cold waves only:
negative 10,000 net excess deaths per annum due to global warming in developed (ie, primarily mid latitude northern hemisphere nations) because lives saved due to less cold warmer exceeds lives lost due to heat waves.

45,000 net excess deaths per annum due to global warming in developing nations (ie, primarily low latitude nations) due to more deaths due to heat waves, with lives saved due to reduced cold weather not being significant because cold weather does not exist in the tropics.

Is your focusing solely on the first figure an oversight, or a value judgement?

Anonymous said...

Great - now you guys have unwittingly unleashed another AGW related cause of death.

Hank Roberts said...

How did Reddit identify the sock-puppeteers?

a_ray_in_dilbert_space said...

Hank,
P. Z. Myers has had pretty good luck banning multiple sockpuppets belonging to the same IP address.

EliRabett said...

Wm. you are falling into Lomborg fallacy land there, that money spent on A precludes spending money on B. Details at the link