FACTBOX: Deciphering the jargon in the climate debate

(Reuters) - The greenhouse gas-cutting bill passed by Democrats on the U.S. Senate Environment and Public Works Committee is not all the climate change debate has brought to Washington. Politicians, pundits and lobbyists alike are now speaking a new jargon as they try to tackle global warming.

Here are some terms being thrown around in the climate debate.

GLOBAL WARMING - The gradual rise in the Earth’s average temperature thought to be caused by additional heat being trapped in the atmosphere by a buildup of greenhouse gases. Scientists say the change in climate brought on by global warming could cause flooding from melting ice caps, more severe storms and droughts. The theory is still hotly disputed by some groups, including some Republicans in Congress who don’t believe global warming has been proven as a threat.

GREENHOUSE GASES - Chemicals that trap the sun’s heat near the Earth like a blanket. These chemicals include methane and carbon dioxide. Supporters of climate change legislation blame carbon dioxide emissions from burning fossil fuels for global warming.

CARBON FOOTPRINT - A measure of the impact of human activities on the environment in terms of the amount of greenhouse gases they produce, measured in units of carbon dioxide.

CARBON OFFSETS - Paying to make up for carbon emissions. Websites are now dedicated to allowing consumers to pay to have trees planted or contribute to a wind farm to make up for the carbon dioxide emitted when they drive or take a flight. A more formal, albeit unregulated, global voluntary carbon market also exists in which companies can buy verified emissions reductions to reduce their carbon footprint. The recession hurt demand for these offsets, which currently trade between $3 and $11 a tonne, but prices and demand are starting to improve.

CAP AND TRADE - A system that sets limits on harmful emissions, giving allowances to affected industries within these limits, or caps. Companies with emissions below the cap could sell their extra allowances to bigger polluters on a new financial market exchange. The Obama administration and Democrats in Congress support the system, but Republicans argue it would push more manufacturing abroad and raise energy prices.

CARBON PERMITS - Used in a cap and trade system, they bestow on their owner the legal right to emit greenhouse gases. Climate legislation in the Senate has outlined a plan for distributing the permits.

CARBON TAX - A policy that would tax fossil fuels based on their carbon content. It would be used to encourage the use of more clean energy sources. The corporate world has shown some support for this policy tool, but it has made little progress in getting into legislation.

COPENHAGEN - Location of an international summit to be held in December on climate change. The hope is for this United Nations summit to bring about a legally binding agreement on how to reduce the world’s carbon emissions. But the United Nations recently lowered expectations for a climate deal at the meeting, saying it was preparing for post-Copenhagen talks. The United States is pushing to make gains on its own climate legislation before the meeting as U.S. leadership is considered vital to global talks.

KYOTO - Short for Kyoto Protocol, an international agreement adopted in 1997 in Kyoto, Japan, which sets binding targets for emissions of greenhouse gases that spur global warming. The United States never ratified the agreement, which called for developed countries to cut emissions by an average of 5.2 percent below what they were in 1990, saying it was unfair to exempt developing countries like China and India. The agreement expires in 2012. The world is looking to talks in Copenhagen to build on this agreement.

CLEAN DEVELOPMENT MECHANISM - A part of Kyoto that allowed developed countries to invest in projects, or offsets, that reduce emissions in developing countries as an alternative to more expensive emission reductions in their own countries. Its key point is that it allows for emission reductions that would not otherwise have been possible.

Compiled by Jasmin Melvin in Washington, editing by Alan Elsner and Vicki Allen