Buzz Words of Doom

WUWT has a graph showing the use of "correlation" and "causation" in Google Books from 1800 on. I did a similar search in Google Scholar back in February (don't remember exactly why...). I searched for "global warming" and "anthropogenic climate change", adding "acid rain" afterwards. Here's how often those phrases were used from the 1980s on.

Looks like "global warming" is not as popular a phrase as it used to be. Now, if you do something similar in Google Books, you get this:

(The quality of these snips is not great, but you get the drift. Note also that I've added "ozone layer" to the second graph. The Google Books graph ends in 2008, whereas that for Scholar ends in 2011.)
Acid rain hasn't really gone away, despite peaking in Google Scholar in the early 80s. But if you look at the articles that get thrown up, you see that their geographical coverage is different - they are now focused in places like China, for example.

Does cold kill in the 21st century?

The reason I ask is that when I was clearing out old bills, I found this in the corner of a bill dated November 2000:

The thought occurred to me that global warming might save lives.

We know that heat waves kill. We might guess that cold weather kills also – but how do the two factors balance out? If under global warming we have milder winters, would the lives saved balance out the extra deaths due to hotter summers?

This graph is rather cool. I didn’t draw it myself. Can’t find the data, or I would.

Figure 2 from Brown et al, Exploratory analysis of seasonal mortality in England and Wales, 1998 to 2007, Health Statistics Quarterly 48, Winter 2010. (Available here)

At first sight, it appears that cold kills more than hot. There is evidence of a slight increase in mortality above about 25°C, and a larger increase below about 13°C. There is a lot of scatter for the highest values (above 2000 deaths/day) – more people dying in generally cold times, but apparently independently of the temperature within that range. We might surmise that this is more to do with general winter ailments like flu rather than people freezing to death.

Data here

There has been a general decline in excess winter mortality (definition: numbers dying in December to March in excess of numbers dying in April-July and August-November). In the same period there has been a smidgeon of an increase in average central England temperatures in the four winter months (actually c.1.3°C over the 61 years). The point is, there’s a lot more going on than temperature in the winter. There’s home insulation, and social and health care, all of which may contribute saving lives to different degrees.

If you plot excess deaths against the winter temperature, you get a fairly diffuse relationship (the slope is significant, just barely, but we must be careful not to assign causality too readily - the rise in winter temperatures over the last 60 years might have a small part to play in this compared to health and social care, insulation and clean air).

Save the world - with 2.5 million wind turbines

Image from windturbinezone.com

The Intergovernmental Panel on Climate Change’s Working Group III specialises in mitigation of climate change. On 9^th May, they made a startling announcement.

“Abu Dhabi, 9 May 2011 – Close to 80 percent of the world‘s energy supply could be met by renewables by mid-century if backed by the right enabling public policies a new report shows.”

From the press release

The report on which this assertion is based was recently released, and considers 164 scenarios (of development of renewables, changes in energy use, etc). The relevant chapter can be found here.

The headline-grabbing figure was derived from a scenario in an article by Teske et al. in Energy Efficiency (2011) 4:409–433. Energy [R]evolution 2010—a sustainable world energy outlook.

The Climate Auditor, Steve McIntyre, noticed that the lead author of the important article, a Greenpeace activist, was also involved in writing the IPCC’s report, calling into question their neutrality.

I was interested to know where the figure of “close to 80 percent” came from. Well, as you might expect, a large chunk of the energy comes from wind.

Now, based on Teske et al’s table 7 (p.422), they reckon wind (on- and off-shore) will have an installed generating capacity of 3754 GW by 2050. The number for 2008 was 120.3 GW, and this has of course increased since then.

The generating capacity in 2008 had a potential energy production of 1055 TWh and generated 219 TWh, for a capacity factor of about 21%. The modelled generating capacity in 2050 would have the potential to generate nearly 33,000 TWh if it could generate at nameplate level. If the present capacity factor was maintained, this would actually generate 6,800 TWh, or 24.6 EJ per year, which on their own figures would be <1/6^th of demand. They assume that 39 EJ will be generated at a capacity factor of about 33%, and cover c.25% of total demand.

I was interested to know how many turbines these figures represented. A common nameplate capacity onshore is 1.5 MW, and most capacity is presently onshore (I think the scenario here assumes greater use of offshore, which has a higher capacity factor). Anyway, the 2008 capacity of 120.3 GW would therefore mean we had c. 80,000 turbines in 2008 (I don’t know how accurate this is). The 3754 GW in the 2050 prediction would, at the same nameplate capacity per turbine, require c. 2,500,000 turbines.

At a typical spacing of 10 turbines per hectare, that would require 2500km-sq of land, or a square 50 km on a side, which doesn’t sound too traumatic.

There are other questions to be asked about this article – about the contributions of solar power and biomass burning, for example... and the smart grid necessary for distributing the electricity. The big question is, though: how realistic is this scenario? Is it more like a fantasy?

Phanerozoic CO2

Source: Wikipedia.

The graph that made me wonder just how bad CO2-induced climate change can be.

Dengue fever

Dengue is a mosquito-borne virus which affects some 50 million people a year. A report by the BBC blames climate change for the growth in Dengue:

"Some scientists say climate change is to blame, with rising temperatures and increased rainfall boosting the number of mosquitoes, which carry the disease."

However, another piece by the BBC says it is overpopulation, slum conditions and air travel that are to blame. A much more plausible explanation. It is far too easy to point the finger at climate change without a shred of evidence. However.

It was actually a third BBC report on Dengue that I was searching for when I came across those two articles. Entitled 'Lame' mosquitoes to stop Dengue, the piece explains how a team of scientists has genetically-engineered male mosquitoes to carry a dominant gene that prevents flight muscles from forming in the female. Original article: [Female-specific flightless phenotype for mosquito control, Fu et al, Proceedings of the National Academy of Sciences, February 22nd 2010] (free access to pdf of article)

Now, will it work? Will releasing sterile males into an outbreak population (or an endemic one) reduce the numbers of mosquitoes? At first sight, the plan seems flawless. We can release thousands of males (they don't bite, remember - only the females do), each carrying a little time bomb - a genetic one. Each female that mates with one of our males will produce two kinds of offspring: males with the inhibitor gene but that are unaffected by it, and females that can't fly, and thus can't feed, or reproduce. What's not to like?

The plan does have potential, but it is most likely of short-term effect. Natural selection is a wonderful thing, and there will be very strong selection against our males (because they produce half as many viable offspring as a non-modified male). The question really is whether such hi-tech solutions are really of any point, when cheap environmental solutions could be put in place much more easily and with permament effect.

For instance, putting lids on water butts might be an effective way to reduce standing water for mosquitoes to breed in (if this sounds naive, it shouldn't - Dengue is present in built-up areas, including relatively affluent ones). Clearly such an approach is laughable where waterways are little more than open sewers... but building new sewage systems not only combats Dengue, it combats a bunch of other stuff too.

Climate scepticism on the rise

Last week the BBC reported that climate scepticism is on the rise. Between November and February there was a 10% increase in the proportion of people who don't believe in global warming, from 15% to 25%. Now, why?

i) What we might call the no-brainer. We've had a cold winter in the UK. Therefore there is no global warming. With logic like that, it's no wonder we're still the world's greatest Empire.

ii) The "Climategate" emails. Why does every scandal have to have the word "gate" appended? I know, it's because of the Watergate building. Well maybe we should call it the "WaterClimate" conspiracy for a bit of variation. Was there anything to disprove global warming in these emails? Not really. Enough to paint the scientists concerned as human beings, i.e. not the ivory-tower ascetics we might have suspected they were. You didn't expect that? H'mm. Steve McIntyre's blog has good coverage of these (though some would say it is not entirely neutral). You can get the raw emails here.

iii) The Himalayan glaciers. The Internation Panel picked up on a story that the Himalayan glaciers would be gone by 2035 and put it in their state-of-the-end-of-the-world report. Trouble was, the story had no basis in science. Whoops.

iv) The slow drip of confusing allegations by sceptics. "The Proxy Data are wrong." "The Hockey Stick is an invention." "Carbon dioxide is already saturating in the atmosphere." "Use a trick to hide the decline." (the latter from the Climategate emails). (See ClimateAudit again for these; RealClimate has the orthodox view.

v)The UEA, host of the Hadley Centre (Climate Research place), found to have dealt wrongly with the Freedom of Information requests by sceptics searching for a global conspiracy.

Well, that's quite a bit of negative press. To address item i) alone for now. You know the problem? It's simple. If we have a mild winter, experts are wheeled out who say (or are made to say by journalists) things like "we'll expect more weather like this with climate change." Ditto summer heatwaves. They're due to global warming, as are storm surges and rainstorms leading to floods.

Then we have unseasonally cold weather, the folks in the public put two and two together and work out that the same causal attachment should be made between climate and all spells of weather, not just the ones that fit the picture that the media now expect. All of which is nonsense, but natural.

So next time there is a heatwave, listen out for any voices mentioning global warming. There will be some.

The other items on the list will have to wait for another day, but I will address them all in time.

Per capita carbon emissions vs GDP

One thing that has always concerned me about climate change is the way the government’s approach has whiffed sharply of hypocrisy. In the UK, we are going to have new runways, we are said to need 240,000 new homes a year, and car manufacturing is trumpeted as Definitely Good for the UK. On the other hand, Govt. is always talking about CO2 like the world will end if we dare to so much as breathe out. So, which is it to be? Go after CO2 emissions or let the economy grow? Politics seems to be an attempt to dodge a falling rock by moving both directions at once. It’s impossible. You have to jump one way or the other. Which way they jump, I have never really minded (I just would like the Grey Suits to be consistent – either consistently determined to grow the economy come what may, or consistently determined to cut CO2. Then we can vote according to which view we like. Just be honest, guys.)
What of the “low carbon economy”? Can there be such a thing? Can growth come at the same time as CO2 is cut?
I’ve just compiled some data to find out. It turns out, if history is a predictor of any sort, that growth at the same time as cutting CO2 is impossible.

The graph (click it for clearer version) shows year-on-year changes in per-capita CO2 emissions against the deviation in global growth from what the IMF term the global recession level, i.e. 3%. Which way you should plot this could be argued. Perhaps it should be the other way around, with CO2 emissions driving GDP growth. In either case, the line is the same, as is the conclusion: When the global economy grows, per-capita emissions grow. “Sustainable Growth” is a politician’s myth. We can have Sustainability or Growth. Not both.
One caveat: there is a possibility that some of the two data sets actually have the same source. For example, some carbon dioxide emissions might be estimated by economic activity. This shouldn’t be a problem, because the raw number for CO2 (its atmospheric concentration) is well known, and population size ought to be independent of GDP. Ought to be. I just don’t know exactly how the data was produced.
Data sources:
Carbon Dioxide Information Analysis Centre
IMF economic database