Friday, January 29, 2010

Adapt or die

There's an interesting article in Climatic Change which looks at temperature-related mortality in England and Wales in recent decades. They use detection-and-attribution methods to look at the influence of climate change and adaptation.

Given the lengthy introduction citing numerous hyperbolic warnings about the primarily negative and potentially disastrous health effects anticipated due to climate change, it is mildly amusing (though hardly surprising to anyone familiar with the literature) that they observe that temperature-related mortality has decreased sharply over the interval studied. More interestingly, they find that a major cause of this decrease is not even the warmer winters the UK has seen, but rather better adaptation to cold weather. This of course directly refutes the "optimally adapted" meme, since if that was the case, we would expect to see a decrease rather than the observed increase in tolerance to cold extremes as the winters got warmer. But in reality, wealth and technology (eg insulation, heating and clothing) act to increase our tolerance whether or not the climate changes, although the latter may in theory act as an additional stimulus if it were sufficiently important (which it clearly is not, in the UK).

Of course they have to finish off by talking about increases in heatwaves, wondering "whether adaptation will manage to keep pace with such changes". I think it is patently obvious that it will, and would happily bet against any predictions of increasing temperature-related deaths in coming decades.


Unknown said...

Is your betting offer confined to increasing temperature-related deaths in the UK / high northern latitudes or does it extend globally? :)

I don't know enough about the medical science involved, but I would've thought that the number of potential extra deaths from any change in temperature is a non-linear function of the baseline temperature...

A change of +5 degrees if your existing temperature is 10 degrees shouldn't require any action at all. Adaptation to 25 degree mean summertime temperatures from a baseline of 20 wouldn't be difficult. I imagine adaptation to 45 degrees from an already-sweaty 40 deg baseline is a different matter, even before accounting for the likely widening of the min-max distribution.

(Likewise for cold deaths, obviously, if global temperatures were heading the other way.)

Arthur said...

There's a fundamental difference between adapting to cold, and adapting to heat, though. With cold, all you need to do is keep heat in, insulate sufficiently, have warm enough clothes, etc. Aside from accidents related to ice and snow, dealing with cold requires only employing passive materials. It's not free, but it's not hard.

Adapting to heat on the other hand is a lot trickier because our bodies generate heat and we require some way to have that heat removed from us. That's not too much of a problem if temperatures stay below body temperature, but above 37 degrees active measures become essential. Evaporative cooling (sweat) works to a point, but at the least requires increased water consumption. Air conditioning requires significant energy consumption (though the rate for a building can be reduced through some of the same passive measures that keep the building warm in winter).

That is, keeping warm when it's cool requires only one-time capital; keeping cool when it's sufficiently hot requires ongoing consumption of water and energy.

That's not just a theoretical consideration; if you look at the curves of mortality vs. temperature (I don't recall the study, but it was from a few years ago) the slope up from the minimum at optimal temperatures is very gentle towards the left (cooler temperatures) but rises steeply on the hot side.

Anonymous said...

We can adapt to heat, given enough resources, but adapting the rest of the ecosystem to heat is a completely different matter. Most of them don't have the ability to do so.

Even though we can adapt given the resources, climates that are borderline extreme heat are now going to experience more days of devestating temperatures. 47C is enought to kill an established plant in one day that has survived or years in temperatures that don't range much over 40C.

Anonymous said...

If James Hansen's 5m sea level rise by 2107 is correct, it will be hard for those in the Maldives to adapt. Actually a much smaller rise will prove difficult

Multi decadal droughts are also a little hard to adapt to.

I am sure there will be thresholds that we will cross without being aware just how critical they are, or even that they are approaching.

Unfortunately man usually does all his adapting post event.

Tony O'B

Jesús R. said...

Well, a global study would be more interesting. I think this is a rather uncertain area, so I highlight a peer reviewed study suggesting the opposite:

"These findings suggest that increases in heat-related mortality due to global warming are unlikely to be compensated for by decreases in cold-related mortality and that population acclimatisation to heat is still incomplete."

Magnus said...

Well, as a Sweed wisiting the UK... I can just say they have lots of adaption left to do! Damn I live close to the polar cirkel and our indoor climate is so much better... guessing they could save much money on energy...

C W Magee said...

Are there fewer cold-related deaths in the UK because houses are insulated better, or because fewer people are getting tanked and falling asleep in snowdrifts?

Reducing the number of people sleeping on the street would probably be more effective than insulating the houses they are sleeping in front of.

James Annan said...

I haven't looked into the global situation in any detail, but I would expect that the same would be true. Note that the warming is going to be higher at high latitudes and in winter, which are precisely the areas that will have the greatest benefit from warmth.

Jesus, that's an interesting link which illustrates all that is bad in this area of "science". The authors manage to find some analysis that makes hot weather look bad (note they do not look at all temperature-related mortality, but just brief extremes). The extrapolation to future changes is a pure guess, they did absolutely no analysis of temporal trends. All studies that I am aware of that do this find that adaptation is a major factor (this one I just cited is the first that I know of that shows that adaptation to cold has actually been greater than the winter warming).

Chuck and Magnus, even though UK housing is often grotty, it is improving. Much of it is 100y old of course. Double glazing was pretty much unheard-of when I was growing up, but it's standard in all new builds now (probably required by building regulations). The mortality figures are much broader than just a few tramps or drunks.

Arthur, it will be a long time before the UK's summer approaches Japan for nastiness - but here although there is a barely measurable blip in August mortality, it is still way below all winter months. A lot of the "adaptation" only consists of things like wearing a hat and not searching out the hottest places in the middle of the day for sunbathing...took me a few years to adapt to the large step-change when I moved here, the last few summers have been reasonably tolerable (I wouldn't say I actually enjoy them).

Chip Knappenberger said...

I can talk a little bit about temperature/mortality responses in the U.S.—we are adapting, especially to heat. I have been a co-author of a series of papers which shows a declining sensitivity to extreme heat in most major cities in the U.S. since the mid-1960s (e.g., Davis, R.E., Knappenberger, P.C., Michaels, P.J., and W.M. Novicoff. 2003. Changing heat-related mortality in the United States. Environmental Health Perspectives, 111, 1712-1718). Also, the hottest places in the U.S. are the places with the fewest extreme heat deaths. It is the rare heat wave which kills people. As heat becomes more common, people deal with it better.

And as far as a seasonal response goes, we have a paper which looked at that as well (Davis, R.E., Knappenberger, P.C., Michaels, P.J., and W.M. Novicoff, 2004. Seasonality of climate-human mortality relationships in US cities and impacts of climate change. Climate Research, 26, 61-76). Basically, there is hardly any difference in the seasonal mortality cycle whether you are in a warm city or a cold one—where you live in the U.S. has little impact on the weather-related mortality. In the U.S., mortality has become largely dissociated from the weather/climate (i.e. climate/weather mortality is lost deep in the noise). I would bet along with James, that this will hold true (if not more so) in the future as well.


Hank Roberts said...

Do you all get AGU's EOS?

I went back to the 31 March 2009 issue
reminded of this:

"... further scientific effort will never eliminate uncertainty; it may in fact increase uncertainty. For example, 3 decades of research on climate sensitivity ... have not reduced, but rather have increased, the uncertainty surrounding the numerical range of this concept. The lack of climate predictability should not be interpreted as a limit to preparing strategies for adaptation....
... society will benefit more from having a greater understanding of the vulnerability ... than from any ... increase in the accuracy and precision of climate predictions."

It's basically an argument against spending money on the next generation of climate computers, and for spending it instead on, I guess, vulnerability and adaptation studies -- the political science side, I guess.

Authors: Desai, S; Lempert, R; Pielke, R. Jr.

Hank Roberts said...

> declining sensitivity to extreme
> heat in most major cities in the
> U.S. since the mid-1960

Hmmmmm. Any correlation to the introduction of air conditioning in homes, cars, and public places? That ought to be trackable. If so it might be possible to correlate adapting to extreme heat with actions that increase the heat outside the adapted area.

Unknown said...

James, I think that adaptation is relatively easy for high(ish) latitudes provided droughts or sealevel rises are not a problem. As you move nearer the equator, consequences of increasing temperature will be far less easy to deal with. For an example, see Burke et al., 2009, PNAS 106, 20670-20674. I think a nuanced analysis must take the current baseline climate into account.

Sure, the Swedes and so on will be happier as it gets warmer but most people will not. Support for this assertion can be found in Rehdanz & Madison 2005, Ecol. Econ., 52, 111-125. You may find their analysis to be of interest.

Chip Knappenberger said...


You are right on!

Here is what we concluded in the EHP paper:

"This systematic desensitization of the [U.S.] metropolitan populace to high heat and humidity over time can be attributed to a suite of technologic, infrastructural, and biophysical adaptations, including increased availability of air conditioning."


Hank Roberts said...

> air conditioning

So, any number on how much the rollout of air conditioning everywhere has contributed to committed warming/CO2 in the air?

Roger Jones said...


you need to be careful with this one. You're right that winter mortality drops in most places with a pronounced seasonal cycle. However, changes might not be gradual. In SE Australia daily max temp has gone up by about 1C in a step change from 1997. The whole distribution has shifted up.

Looking at shifting the baseline distribution, in hot areas beyond a certain point, temperatures above threshold accelerate with continued warming. It is more serious in tropical areas because the distribution is pretty flat. You could go from a few days a year above 35C to a couple of hundred in a few degrees warming. Of course, social adaptation is the strongest driver, but sudden changes in climate can swamp gradual adaptation.

In Melbourne last month, there was one night where it was 36C at midnight after a day of over 40. In the past few years in Melbourne, Adelaide, Brisbane and Sydney, period above threshold records have all been broken. We have put in public health strategies to manage this but public housing is woeful at temperature management. Guess where the most vulnerable live? People bail out and go stay with relatives and friends if they can. And the homeless can at least go to the beach.

James Annan said...

Well, I'm definitely confident about the UK. but different bits of the planet may feel differently about it. I know that lots of British people cite the weather as a reason for wanting to emigrate to Australia!

Hank, aircon is a major energy use in hot areas and can increase the local ambient temperature a bit. I can't remember exactly what I've read about this...