The Optimum Population Trust recently published a study which claims that Britain's optimal population is about 17 million people:
If the UK had to provide for itself from its own resources, it could support a population of only 17 million – 43 million less than its latest official population figure* - according to new research by the Optimum Population Trust.
Even if the UK dramatically improved its sustainability with a 60 per cent cut in carbon emissions by 2050 - the target set by the present Government - UK “overpopulation” would grow from 43 to 50 million, the research shows. This is because projected population growth of 17 million**, taking the country’s population to 77 million by 2050, would cancel out the sustainability benefits of carbon savings.
The sustainability of human populations: How many people can live on Earth? ***, published today (Monday February 18), is based on a new analysis of biological capacity and ecological footprinting data. It suggests that in 2003, the last year for which comprehensive data are available, total world population was 6.3 billion but the sustainable figure was 5.1 billion. Global overpopulation was thus 1.2 billion. (italics in original)
A 9-page report based on this study can be downloaded here. From pages 2 to 3:
Not surprisingly, the impact of this population growth on the environment since 1750 has been extensive. Now, not a day goes by without news of droughts, floods, famines, conflicts over resources, extinctions, and, in the last 20 years, the increasingly evident effects of global warming. This impact has been expressed in what has become known as the Commoner-Ehrlich Equation:Note that it is assumed that technology is multiplicative factor that increases the human impact on the environment. Yet technology mitigates the impact we have on the environment by enabling more efficient use of resources and/or less polluting methods to be used.I = P x A x T.This states that the impact (I) on the environment is directly proportional to the population size (P), the ‘affluence’ (A) (defined as the resources a population consumes and wastes) and technology (T) through which we (1) prolong life, (2) produce things more quickly and cheaply (thus feeding back into consumerism and affluence) and (3) grow food faster which feeds back into ‘population’. This equation thus neatly summarises the impact of humankind on the planet.
It is technology that has enabled us to sustain the large population we currently have on earth, living longer and healthier than at any time in history. Remove the technology and the environment would be devastated as people desparately try to grow food and obtain water using methods that simply cannot sustain us. Indeed, based on similar points to mine above, Tim Worstall argues that we should divide by T rather than multiply. However reading further, it seems that T isn't measuring technological advancement, but rather the impact of technology on the environment:
Politicians, unsure what to do, offer solutions which include suggestions such as: develop fuel-efficient cars; change to efficient light bulbs; fly less; build renewable energy and nuclear power plant; increase mass transit systems; and plant trees. These solutions only address the reduction of the affluence and technology variables of the equation, but never the population variable.Here the paper acknowledges that technology can in fact reduce the impact of humanity on the environment (though it argues that the drive to economic growth will then cancel this out). To retain T as a multiplicative variable, whilst acknowledging that it can reduce humanity's impact on the environment, one must consider it to be a measure of the impact of our technologies on the environment, rather than a measure of advancement. Technological advancement will thus tend to reduce T, and I'd suggest it has been doing so for centuries whilst increasing population and affluence have offset the reductions in impact it enabled.
Reducing impact by decreasing affluence (consumption) only partly addresses the problem since populations are growing faster than affluence – for example, in Africa. Technology, meanwhile, tends not to “decrease” at all. Whilst it can be used to reduce the impact of affluence, it is likely that its benefits in energy saving devices will be cancelled out by its disadvantages, as businesses continue to use it to maximise their economic growth via consumerism. So, realistically, impact will continue to rise since economic growth demands it. This is bad news since, as we will now see, human impact on the planet is already unsustainable. (italics in original)
An interesting point is that there is no mention in this study of one of the main findings in demography which is that increasing affluence has lead to a fall in birth rates resulting in slow population growth rates or even declining populations in rich countries. This implies that rising affluence may in fact help with the goal of slowing population growth, a finding that is at odds with the arguments presented on the OPT's paper.
I intend to return to other aspects of this paper in later posts.
4 comments:
The question of the Technology factor (T) is often misunderstood (also by Tim Worstall), because it is a broad brush which covers a an enormous breadth of engineering and scientific innovation over a long period of time. Some applications of technology increase impact and some (more recently) do reduce it. You correctly point out that I mention both types in the paper but the full analysis of T could fill several books. For that reason it was glossed over in my paper. I now realise I should maybe have treated the T factor in a bit more detail.
By definition, when T is between zero and one, it reduces impact and when T is greater that 1 it increases impact. As you rightly point out I mention cases where T improves efficiency as well as other cases where it clearly does not. So let us agree that technology can have both good and detrimental effects on human impact on the environment. The question is: Does 'impact-reducing' technology outweigh the effects of 'impact-increasing' technology? On balance, is the aggregate value of T bigger or less than unity? Let us examine this in a bit more – qualitative - detail.
I think it is safe to state that, since the industrial revolution, technology has enabled us to reduce infant mortality, increase food production and increase life expectancy, all of which have caused the largest population explosion in the history of humankind. I think we can also safely assume that in that arena T is greater than 1 as a result. Such progress was possible only because we could extract oil, coal and gas out of the ground in ever increasing quantities, transport it via road, rail, pipe and sea* all around the world which, I feel sure you will agree, has also had a T-greater-than-one impact on the environment. In addition, we get most of our fertilizers from hydrocarbon technology. Without fossil fuels and thereby electrical energy, medical advances would have been impossible, We would not have been able to develop (to mention those which immediately spring to mind): warm homes, fridges, leisure centres Olympic stadia, moon shots, as well as several billions of cars, millions of lorries, ships buses, railways, aircraft, agricultural machinery factories, processing plant …. with all the infrastructure of roads, ports, depots, etc that these entities require.
Had the extraction and synthesis of fossil fuels not have been possible, then few, if any, of the above advances would have transpired. And as a result, I suppose, the human population might just have reached the 1 billion level, having continued to be regularly culled by famines and plagues, not to mention the inevitable resource wars. Thus, if it is logical to conclude that without technology the population of the world would have been very much lower than it is today, then we are forced to accept the premise that technology is an important driver in the impact equation and T must be greater than one – overall. And that, I think, is really all that Commoner and Ehrlich ware proposing and, I presume, what Tim Worstall does not understand.
I think what clouds the issue of T is that, increasingly, technology is now being very slowly turned back on itself – so to speak. We, having realised the error of our ways, are trying to use it to reduce its own impact by e.g. making all conversion processes more efficient: reducing heat losses; making more energy-efficient gizmos recycling; etc.
Large corporations compete to survive, by telling us all to buy, buy, buy. So when their products become less competitive they find ways to reduce production costs – unfortunately not always ethically. That is why today you can buy a car for £10k with features which would only have been available on a £30k vehicle 20 years ago. Think about the ubiquitous TV set. In 1950, they were not only black and white, they were unreliable and most of all – rare! Perhaps one in a hundred households owned one. Today, most homes have two – or more! This is all due to technology. It feeds affluence and expectations. We see this process – in catch-up form - proceeding apace in India and China today. In the case of China, the population in not increasing significantly, but its impact is. Why? Because technology makes it possible for them to strip-mine coal and develop and build millions of cars, add one coal-fired power plant a week to their energy industry. So is becoming an increasingly affluent society (with a fair way to go to catch up on the rest of us) making an adverse impact on our planet. I need only mention the Beijing smog. I am not singling out China for any other reason than at this point in time it is a good example of the high-impact effect of technology. We are all guilty of it. Los Angeles and London also have and have had their smogs. Of course technology helped London get rid of its smog back in the late 1950s, but that advance had a downside that few care to mention. We all used more smokeless coal and then and oil and later gas. We all got hooked on central heating and put more and more CO2 into the atmosphere.
So we can see that, as technology solves our problems, it encourages us to use the products more, and the energy we spent on developing them is then used in producing them in mega-quantities. And the sad thing is that the laws of thermodynamics predict that every time we make a gain – in anything we do –it costs more energy that it ultimately saves. That is why there is no such thing as a perpetual motion machine.
There we are, James, my reply has turned out to be longer than your blog, but I did say the analysis of T could fill several books. And I didn’t even mention the development of plastics, pesticides, desertification, soil erosion ….
Oh, well … I think I’ve convinced myself that the effect of technology is to increase impact … and with a vengeance. I hope I’ve convinced you and your readers of the same. Thank you for bringing up the subject.
Maybe you or your readers would like to become a member of the Optimum Population Trust. We really are all friendly, well intentioned and well informed and we are campaigning for a better world to leave everyone's descendants. Check us out on www.optimumpopulation.org
*sometimes losing it at sea like the 11 million tones lost by the Exxon Valdez into the pristine wilderness of Prince William Sound, Alaska.
"Thus, if it is logical to conclude that without technology the population of the world would have been very much lower than it is today, then we are forced to accept the premise that technology is an important driver in the impact equation and T must be greater than one – overall."
Nope, that's double counting. We already have P in the equation so you can't state that T allowing higher P means one must multiply by it.
Similarly, all that stuff about TV sets is encompassed in A. Again, using T as a multiplier is double counting.
The Impact will be the Population and the Affluence of it adjusted by the Technology that is used to produce that affluence for that population.
Think of it this way, is oil a higher technology than coal? I would say so, it's certainly a later historical one.
If we tried to have 6 billion people living at current standards of living entirely powered by coal rather than oil would that have a greater or lesser environmental impact than the current oil/nuclear/coal mix?
I think it's fairly clear that coal would have the greater impact (in fact, I think one of the truly horrible IPCC scenarios explores this option and proves it).
Thus T should be used to divide, not multiply.
Tim, Martin, thanks for your comments. I shall be responding to these in the form of a new blog article shortly.
My response can be found here:
http://jameshammerton.blogspot.com/2008/03/technology-and-humanitys-impact-on.html
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