Greenhouse gas emissions, such as carbon dioxide, are created in part by burning oil and coal for transportation and electricity.

VOA: special.2009.12.26

Natural gas is considered the cleanest of the fossil fuels, the fuels created by plant and animal remains over millions of years.

VOA: special.2009.10.23

Carbon monoxide gas is created by fuel burning devices because not all of the fuel is burned.

VOA: special.2010.02.02

Gas shale exploration is being done mainly by small to medium sized companies.

VOA: special.2009.10.23

Expanded U.S.sanctions would cover petroleum, petroleum by-products, oil or liquefied natural gas, tankers,and products used to construct or maintain pipelines.

VOA: standard.2009.09.25

Does measures seem to low emissions of greenhouse gases by raising the cost of gasoline, coal,natural gas and other fossil fuels.

VOA: standard.2009.12.12

The demonstrators were kept away from the summit site by thousands of police, troops,helicopters, boats,tall fences and occasionally,tear gas.

VOA: standard.2009.09.25

Mr.Obama and Democrats in Congress are backing a "cap and trade" bill, which aims to cut greenhouse gas emissions 17 percent by 2020.

VOA: standard.2009.05.30

Police responded by using tear gas, water cannons, baton charges and rubber bullets to disperse the crowd.

VOA: standard.2009.09.01

But in certain landfills, including some accepting the BP cleanup, waste,heat and methane gas produced by decomposition are being used to generate energy.

VOA: standard.2010.08.05

The draft constitution laid claim to oil and gas rights that are contested by the central government.

VOA: standard.2009.07.29

Officers responded by firing tear gas shells and using their bamboo sticks to repel demonstrators.

VOA: standard.2009.03.28

By 2013,Lithuania wants to have a new natural-gas power plant, but experts caution that this will not be enough to meet the country's energy needs.

VOA: standard.2010.01.01

Most of the electricity Americans use is produced by coal,natural gas, or nuclear generation.

VOA: standard.2010.03.23

Under his stewardship, the European Union has adopted an ambitious climate-change program that aims to cut greenhouse gas emissions by 20 percent or more by 2020.

VOA: standard.2009.09.16

Police responded by firing tear gas and beating back protesters with batons.

VOA: standard.2009.03.15

Satinath Sarangi, a prominent activist working with the victims of the gas leak, says the fight could be led by the generation born in the aftermath of the disaster.

VOA: standard.2010.06.10

The White House says President Barack Obama will attend next month's climate change summit in Copenhagen,Denmark, and will make a provisional pledge to cut U.S.greenhouse gas emissions by 17 percent from 2005 levels by 2020.

VOA: standard.2009.11.26

It is not clear what it will be able to do to help revive energy talks with Uzbekistan, Kazakhstan and Turkmenistan, During negotiations in the Czech capital,Prague, the three natural-gas producing nations were not convinced by E.U.offers of more trade and stronger transport links in exchange for their participation in a multi-billion-dollar gas pipeline, known as Nabucco.

VOA: standard.2009.05.11