More efficient use of energy can satisfy some of the world's burgeoning demand for energy, but not all of it, especially if living standards for billions of people in developing countries are to be raised. To grasp the magnitude of the problem, consider Asia. With 56% of the planet's population, the region consumes only 23% of world energy, mostly in the industrial sector. As Asia's economies grow and liberalize, hundreds of millions of households and businesses will gain access to electric lighting, refrigeration, communication and other services. In the last decade, per capita energy demand in China, India, Malaysia, South Korea and Thailand has doubled. Even as Asia exploits gaping opportunities to boost energy efficiency, the resulting need for power will remain enormous.40
Barring the development of unforeseen exotic sources energy, what conservation cannot do must be done by nuclear power or renewables. The United States and other nations may resolve the economic, environmental and political problems confronting nuclear power in the coming decades. Indeed, the threat of global warming might impel their resolution, but it would be premature to count on such an outcome.41 If we continue to find large-scale, worldwide expansion of nuclear power unacceptable, renewable energy ultimately must bear the responsibility of limiting CO2 emissions.
The challenge is to use gas not just as a device to delay tough political and economic decisions, but as a way to prepare the energy sector for the next generation of energy technologies.
Some varieties of renewable energy do present a minor greenhouse
threat. For example, some facilities back up intermittently available
renewable resources by co-firing with natural gas, and geothermal
plants can release methane. While biomass combustion releases
only the amount of CO2 absorbed during the plants'
growth cycle, net CO2 emissions result if fossil energy
is used to cultivate, harvest or transport the biomass. However,
overall, renewables are far less dangerous to the atmosphere
than fossil fuels. Comparing renewable and fossil energy on the
basis of full fuel cycles-that is, production and transportation
of fuel, manufacture and operation of generating equipment, and disposal of waste-makes the greenhouse advantage of renewables apparent.42