یک 'راه باید رفتنی' سناریو برای توسعه پایدار و نقش انرژی هسته ای در قرن 21

An increase in the world population has accelerated the consumption of fossil fuels and deepened the pollution of global environment. As a result of these human activities, it is now difficult to clearly guarantee the sustainable future of humankind. An intuitional ‘must-go path’ scenario for the sustainable development of human civilization is proposed by extrapolating the human historical data over 30 years between 1970 and 2000. One of the most important parameters in order to realize the ‘must-go path’ scenario is the sustainability of energy without further pollution. In some countries an expanded use of nuclear energy is advantageous to increase sustainability, but fast reactor technology and closed fuel cycle have to be introduced to make it sustainable. In other countries, the development of cost-effective renewable energy, and the clean use of coal and oil are urgently needed to reduce pollution. The effect of fast nuclear reactor technology on sustainability as an option for near-term energy source is detailed in this paper. More cooperation between countries and worldwide collaboration coordinated by international organizations are essential to make the ‘must-go path’ scenario real in the upcoming 20 or 30 years.

It has been a long time since Sir Isaac Newton discovered the famous law of action–reaction in Principia Mathematica (Newton, 1687), which describes the phenomena of motion related to moving objects in nature. This principle is easily extended to be applicable to a closed system like the ecosystem on our planet. Therefore, it is natural that an external or internal perturbation applied to an ecosystem induces a kind of reaction or response to accommodate the applied action. Humankind has become highly industrialized since the Industrial Revolution in the 18th century. This industrialization has been accelerated based on the energy extracted from fossil fuels such as oil, coal, and natural gas. However, the increased use of fossil fuels has deepened the pollution of the global environment, which has resulted in the increase of greenhouse gases (GHGs) in the atmosphere and distorted the balance of the energy flow in the Earth’s system (Ramanathan, 1988). This is an unintended action on the Earth’s system. Now, the accumulation of GHGs is said to be responsible for global warming which has caused an abrupt climate change and has had various influences on the ecosystem. This is a kind of reaction in the Earth’s system. Recent studies by the World Energy Council (WEC) and also by the Intergovernmental Panel on Climate Change (IPCC) investigated the global warming problem and intensively analyzed the predictable influences on both human life and the ecosystem (WEC, 2007a; IPCC, 2007). The conclusion of these reports requires imminent action to solve these problems. Even though there still remains some disagreement, many scientists now are alarming that the abrupt change of the global environment due to pollution (Risbey, 2008) and the variation of natural resources could threaten the sustainability of human life on the Earth. In other words, pollution and the depletion of natural resources could limit the sustainable development of our civilization. The concept of ‘sustainable development’ is well defined in the famous ‘Brundtland Report’ (UN, 1987) from the United Nations World Commission on Environment and Development (WCED). In this report, sustainable development is defined as “development that meets the needs of the present without compromising the ability of future generations to meet their need.” Actually, sustainable development of modern civilization has been a controversial topic for more than 30 years since the future of humankind was simulated by a computer model called World3 described in the Club of Rome's report entitled “The Limits to Growth” (Meadows et al., 1972). The results predicted by the World3 model gave us two pessimistic future scenarios and an optimistic one. More recently, Turner (2008) compared the three scenarios of ‘Limits to Growth’ with the true data of human history for the 30 years from 1970 to 2000. He suggested that modern civilization is on the trajectory of one of the projected pessimistic paths, which may result in a failure of sustainability in the mid-21st century. However, there is still the possibility of a successful sustainable development in the data of human locus provided by Turner (2008). Therefore, a ‘must-go path’ scenario is proposed which enables humankind to continue with sustainable development up to and beyond this century. An ecosystem also seems to be governed by the law of inertia, which is another famous principle of motion described in Principia (Newton, 1687). From the viewpoint of inertia, the social system of humankind is the same as the ecosystem on earth. If the current dysfunctionality of these two systems is not changed, then the threat on the sustainable development of humankind will remain. Therefore, it is meaningful to derive some ‘must-do’ actions from the ‘must-go path’ on world population, food, pollution, natural resources, and others. The first change is expected from the pattern of energy production and consumption because the reduction of pollution may be the most urgent action. Therefore, a sustainable energy option deployable in the near-term was investigated.

It is evident that one of the most urgent problems to mankind in the 21st century is sustainable development. A ‘must-go path’ scenario for future sustainability is proposed by extrapolating the human history data for the last three decades. Minimizing the use of non-renewable energy resources without further pollution is a key factor to realize the ‘must-go path’. In the ‘must-go path’ scenario, it is assumed that the stabilization of food, services, and population can be reached by supplying enough energy to humankind from the fast nuclear reactor technology and by developing cost-effective renewable energies. The following policies are recommended to the developed and developing countries and also to the international organizations: • For the countries with mature nuclear technologies it is advantageous to deploy fast reactor systems and complete a closed fuel cycle, which will contribute to an increased energy sustainability. • The development of technology on efficient energy use and energy saving has to be promoted and supported by governments and society. • International organizations have to prepare active plans, which encourage more collaboration and transfer of technologies on renewable energy development and carbon sequestration between countries. For breaking the inertia of a moving system, it is required to exert an appropriate opposing force on the system. The bigger the system, the more the work required. Human society and the ecosystem surrounding it are two big systems influenced by each other. It is time for humankind to exert much effort on these systems to change their inertia to another direction towards sustainable development. The work of ‘must-do’ action would be painful but it is our ‘must-go path’. Worldwide efforts are required to achieve sustainable development by following the ‘must-go path’ scenario.