Every study of global climate change has concluded that world average temperatures are rising and that the cause is greenhouse gases, mainly carbon dioxide. These are poured into the atmosphere by our ever-increasing use of carbon-based fuels (coal, oil and gas) that power almost all the world’s energy systems. The world economy is growing and a continuation of the present mix of fuels will make the greenhouse gases in the atmosphere accumulate ever faster. Bringing this runaway problem under control, while continuing economic progress, requires a massive shift away from carbon-based fuels.
The first concerted international attempt at controlling climate change is the Kyoto Protocol. The ratification process was long and contentious, and the nations who have signed the Protocol have a great sense of satisfaction that they have finally done something about global warming. However, they have not actually done much; meeting the goals ofKyoto will have an insignificant effect on emission of greenhouse gases. Kyoto aimed to reduce emissions by the industrialised world by 2012 to 5% below what they were in 1990. That sounds like progress, but the bad news is that economic growth projected for the developing world during that period will increase emissions by much more than thosereductions. In the year 2012, the clock measuring the increasing level of greenhouse gases in the atmosphere will not be set back to 1990, but only to about 2008. It is actions beyond Kyoto that will count.
A look into the future shows the true dimensions of the problem. By the year2050, world population will increase to near ten billion from today’s six billion, world economic output will triple in real terms, and primary energy use will double. I use here and below population figures from the United Nations middle scenario, and economic projections from the International Institute of Applied Systems Analysis (IIASA) scenario B – middle growth (see graph page 37). Other organisations make projections that agree closely with these.
Most of the increase in both population and energy use will occur in the developing world and this is good for the alleviation of poverty. It is also here that there is a real opportunity for change, but before discussing that, it is necessary to consider one more key issue: Time.
Time is an essential factor. It is hard to make governments see the need for action as clearly as the science community does, because serious impacts of climate change will not occur for decades. To most governments anything beyond the next general election is an eternity, particularly if action has significant immediate costs.
Compounding the problem is a tendency for society to rely on science and technology for a quick fix to any serious problem. After all, science and technology have transformed our society and they should be able to come to our rescue, say many. That will not work this time because carbon dioxide remains in the atmosphere for about a hundred years. Even if we could somehow today replace all of our energy sources with ones that emit no greenhouse gases at all, it would still be more than a century before levels in the atmosphere returned to near those of the pre-industrial era.
Because of the coupling of energy to the economy, the existing investment in energy systems, and the huge new investment in energy systems required in the next 50 years, bringing the climate change problem under control becomes more difficult the longer significant change is delayed. The carbon dioxide concentration will increase and become harder to stabilise at a sustainable long-term level. Climate change is like a huge truck that is accelerating as more and more greenhouse gases go into the atmosphere. The sooner the brakes are applied, the easier it will be to bring it to a stop.
Conservation and efficiency should come first on the world agenda for mitigating greenhouse gas emissions and their effects. The cheapest and best carbon-free energy source is energy not used. Built into the IIASA and other projections of future energy use is a decline in what is called energy intensity (primary energy used per dollar of economic output) of 1% per year. This is included in the projections to 2050 that give a world primary energy requirement of 27 terawatt-years per year, compared to today’s 14. (One terawatt-year equals the energy content of about 750 million tonnes of oil; all of Western Europe, for example, currently uses only two terawatt-years per year of primary energy).
If the rate of decline in energy intensity could be raised to 2% per year, the world economy would use 10 terawatt-years peryear less primary energy in 2050 than presently projected. World energy spending would also be nearly a trillion dollars per year less than present projections. This is not easy to achieve, but, as mentioned, the best opportunity lies in the developing world where most of the increase in population and energy use is projected to occur, and where energy intensity is currently about three times higher than in the industrialised world.
The easiest and fastest way to improve energy intensity is by putting modern, efficient energy systems into places where new ones are needed, rather than by retrofitting or scrapping old systems that still have some useful life left. For example, a modern, natural gas fired power plant is about 50% more efficient than an old coal fired power plant. China has already begun to do this; in the second half of the 1990s their economic output increased while their carbon emissions actually declined.
Efficient systems may be more expensive to install than old style systems, although they create savings in the long run. The industrialised world can help enormously in reducing carbon dioxide emissions by subsidising the difference in cost between the two for the developing world, as well as by increasing the efficiency of their own systems.
Much hope is placed in carbon-free energy sources, but, among these, only nuclear energy can be expanded on a large scale today. It faces fierce opposition from some on four issues: radiation, accident potential, waste disposal, and the availability of material for nuclear weapons. The first two are greatly exaggerated by opponents. Studies show that as far as human health is concerned, only wind energy is more benign than nuclear. We live in a bath of natural radiation, and nuclear energy increases exposure by a negligible amount.
Analysis of waste disposal methods has been underway for years and so far no real problems have been encountered. Storage in appropriate underground rock formations will work, though it would have to be done on an international basis because not all countries have appropriate sites. Other methods are under study including one, transmutation, that might decrease the required isolation time by a large amount.
Increased risk of weapons proliferation from an expansion of nuclear power is a concern. We live with it now, and will have to design future systems to minimise the risk. I note that terrorist groups would find it very difficult to extract weapons grade material from spent nuclear fuel.
Other alternatives often discussed are three carbon-free energy sources: solar, wind and biomass. Solar and wind are low energy-density systems requiring much land. For example, a 1,000-megawatt average power solar electric system placed at the equator would require 20,000 hectares or 70 square miles of land, more than one hundred times that required for a nuclear or natural gas plant. Solar and wind also suffer from the problem of intermittence: the sun doesn’t always shine, nor does the wind always blow. Both will have important roles to play and their further development should be fostered, but I doubt they can be deployed on the terawatt scale in the foreseeable future.
Biomass aims to grow plants to use as fuel in power generation. The carbon in the plants comes from the atmosphere and goes back when burned as fuel, in theory giving no net increase in carbon dioxide. However, this is an even lower energy density system than solar or wind. I know of no complete analysis of biomass that includes land use, water requirements, fertiliser needs, transportation, etc. If this is to be anything more than a local source, such an analysis is needed.
One other potentially large-scale system is being examined, called carbon dioxide sequestration. The world has enormous reserves of coal and the idea is to capturethe carbon dioxide produced when it is burned and to pump it deep underground or deep into the ocean, thus obtaining the energy while burying the greenhouse gas. This has not gone far enough to know if it is workable.
Global warming will have very serious consequences and the sooner we start a much larger effort than that in the Kyoto Protocol, the better off we will be. There are many options for the long term, but the one to emphasise now is conservation and efficiency. My next choice would be nuclear energy, but others will have different preferences. Still, if we can reduce energy intensity more rapidly than the historic trend, we will have a bit more time to sort out those choices.
Doing anything sensible about energy will be difficult and a major part of the difficulty is the perverse answers that today’s economic analysis gives. At present, economic progress is measured in terms of the current rate of increase in GDP while ignoring what the economists call externalities, such as environmental degradation and the cost of clean-up. So, in long-term environmental issues, it often turns out that bad is good and good is bad. For example, the quickest route to increasing GDP would be to expand energy by building more conventional power plants. The cost of future clean-up is hidden in the externalities that are not included in analyses because the methodology does not exist. If such things were included, I expect we might get very different answers.
The World Summit on Sustainable Development this summer in Johannesburg may bring an increased awareness of the problems. It will be difficult to galvanise governments until we have mainstream “sustainability economics” to go with sustainable development. A policy of business as usual will surely result in severe problems 50 years from now. This will be our grandchildren’s problem, but they are too young now to do anything about it. We had better begin.
©OECD Observer No. 233, August 2002