Rich and developing countries alike have woken up to the reality that cheap and plentiful energy can no longer be taken for granted and that growing demand is harming the environment and quality of life.
Efforts to reduce energy consumption or increase the use of renewable sources are hampered by the fact that economic growth brings higher energy needs and it is still more expensive to produce power from the sun, wind and waves than from fossil fuels.
Yet governments do agree that using energy more efficiently will go some way towards ensuring that the climate isn't harmed by efforts to raise living standards worldwide.
The following is an overview of steps being taken in key countries and regions including the European Union, the United States, China and India to enhance energy efficiency.
European Union
The first report by an EU group appointed to study competitiveness, energy and the environment was produced in June 2006. It states that there is still "a significant potential for improving energy efficiency."
An effective energy efficiency policy could make a major contribution to EU competitiveness and employment, according to an EU "Green Paper" or preliminary report, on energy efficiency. The European Commission followed up these reports with an action plan, which proposes 75 measures to achieve energy savings of 20 percent by 2020.
The United States
Through several programs, the U.S. is seeking to reduce its dependence on oil, and is promoting energy efficieny and the use of alternative resources.
Several states are taking action of their own. Ten north-eastern states are part of the Regional Greenhouse Gas Initiative that aims to keep emissions from power stations unchanged by 2009 and reduce them by 10 percent by 2019.
California, the world's 12th-largest emitter of greenhouse gases, in August 2006 approved legislation requiring a 25 percent reduction in carbon dioxide emissions by 2020.
China
China accounts for more than 12 percent of global carbon dioxide emissions, making it the second-largest emitter after the U.S. The country's latest five-year development plan lists energy and environmental challenges among issues of priority.
The plan for the years 2006 to 2010 calls for a 20 percent reduction in the amount of energy used per unit of gross domestic product (GDP). It also aims to reduce emissions of major pollutants by 10 percent.
A Cleaner Production Promotion Law came into effect in China in 2003 and commits governments at all level to "give priority to purchase products conducive to energy and water conservation, waste reuse, environmental protection and resource conservation."
In addition, The China Sustainable Energy Program has been created by private foundations to support China's policy efforts to increase energy efficiency and renewable energy.
India
In 2001, India passed an energy conservation act as part of a strategy to make power available to all by 2012. The government identified efficiency and conservation as the cheapest option for narrowing the gap between supply and demand.
Other national policies
The International Energy Agency's (IEA) database of national policies on energy efficiency provides a comprehensive guide to the measures being taken by governments around the world.
Energy efficiency policies have been maturing over the years. A study commissioned by the IEA assesses the lessons to be learned from recent decades.
For additional links to government-related Web sites, please see the list in the right-hand column of this page.