Energy efficiency is a powerful tool as part of the solution to reduce anthropogenic emissions of greenhouse gases. The strength of energy efficiency is that adopters are interested in the services that energy provides, not physical units of energy. However, we have endeavored to show that energy efficiency declines should not be thought of as linear trends stretching out over the next 100 years. Instead the mechanism by which energy efficiency develops is a messy, interactive and complex one, existing endogenously within the framework of human activity.
Energy efficiencies can be defined for specific activities over decadal time scales. Aggregation over economies to compare overall energy intensities is complex and controversial, and is limited spatially by climate, economic and social differences between nations, and temporally by the evolution of social mechanisms and the use of as-yet-undiscovered technologies.
Efficiency improvements occur mainly when structural changes in the economy occur. This may be in the retirement of old capital at the same time a new technology becomes available, or when changes in a sphere of human social and economic activity result in the employment of new energy technology. On this bumpy road to efficiency improvement, technological change is not the driver of efficiency improvement. Rather it should be thought of as endogenous to the changes in the economic, social, regulatory, and technological paradigms. It is these interactions that make energy efficiency trends so difficult to project into the distant future.
When trying to predict long term changes in energy efficiency, the contribution of developing countries will be crucial. This is because the bulk of the world is moving toward greater use of fossil fuels and the movement to industrialized societies will be based on rising energy consumption. Despite the importance of developing countries, most efficiency analysis has been carried out on the industrialized world. Additionally, the future development of industrialized countries and the path of energy intensities that they will follow is very uncertain.
Interestingly, some of energy efficiency's fiercest and longest-standing proponents make the mistake of implying that efficiency is so powerful and the market so effective that policy "trimtabs" to correct "subtle" imperfections are all that's needed to address the needs of climate change policy. Certainly numerous studies support the contention that energy efficiency investments can not only reduce energy use and greenhouse gas emissions but can do so while improving economic performance, increasing jobs, enhancing overall environmental quality, reducing the price of non-energy goods and services, and increasing household wealth. But this will not happen by itself, and various policies to promote energy efficiency have been discussed. Policy options include a realistic price of energy that internalizes all the costs associated with its use and hence increases the motivation to save energy. In light of the political intractability of achieving meaningful energy price increases, another set of policy options that allow the economy to set itself down a path where energy efficiency products are offered by suppliers, bought by adopters and continue to decline in price and improve in performance are particularly important for a long-term climate abatement strategy at reasonable cost. These policies include increased RD&D for energy efficiency technologies, support mechanisms for adoption, and energy standards.
Energy efficiency can be thought of as making a little go a long way. Azar and Dowlatabadi (1998) estimate that to meet a 450ppm CO2 concentration target, given no energy intensity reduction, 2700 EJ/year of carbon-free energy would be required. As present global energy supply is of the order of 400 EJ/year, this requirement is clearly enormous. Given the nature of energy efficiency development through interactions with social and economic evolve-ment that we have stressed throughout this chapter, a conservative estimate of long run annual decrease in global energy intensities is 0.5% a year, resulting in the need for only 60% of this estimated carbon-free energy or 1630 EJ/yr. If, through policies to encourage the development of more energy efficient technologies and support for those adopting and using these technologies, an average improvement of 1% per year is achieved, then only 37% or 990 EJ/year is required. If, with determined efforts, the average energy intensity is reduced by 1.5% a year, then only 22% of this carbon free energy or 600 EJ/year is required for atmospheric CO2 stabilization at 450ppm. And if, through even more aggressive policies, energy intensity is reduced by 2% per year, then only 9% or 250 EJ/year of carbon-free energy would be needed. However, with present global energy supply at around 400 EJ/year, this transition to carbonfree energy sources by 2010 would still be a major endeavor.
These numbers indicate that energy efficiency cannot be the whole solution but is an essential part of a solution to abate greenhouse gas emissions without the need for huge quantities of carbon-free power. A little efficiency does go a long way.
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Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.