Every time we heat our homes, take a flight or drive the car, fossil fuels are burnt and CO2 is released into the atmosphere causing climate change. Carbon offsetting enables you to take responsibility for the carbon emissions you create by paying an organization to reduce CO2 emissions in the atmosphere on your behalf. A carbon offset is measured in tons of CO2, and the product you purchase is an equivalent Emission Reduction quantity.
Criteria
There are certain criteria that a ton of Emission Reduction must meet in order to be classified as a carbon offset:
•   It must be carried out in countries which do not have Kyoto Protocol targets (so largely carried out in the developing world).
•   It must not be double-counted towards any signatory country reduction targets (for example, this means that at the moment they cannot occur in the U.K.).
•   It must be additional – this means that the emission reduction project providing carbon offsets could NOT have gone ahead without the financial support of carbon offset money.
In short, a carbon offset is a useful tool for voluntarily reducing your net emissions to zero now, whilst working on reducing your carbon footprint in any way you can. Industry is increasingly being set Kyoto or government reduction targets, but the purchase of carbon offsets allows everyone from individuals to large corporations to make reductions above and beyond those their government has committed to.
Carbon Offset Technologies
Carbon offsets come from emission reduction projects that use energy efficiency and renewable technologies, such as:
•   Wind power
•   Hydro power
•   Renewable biomass
•   Efficient cooking methods
•   Human energy
The majority of environmental organizations and opinion leaders agree that carbon offsets have an important role to play in tackling climate change. The first step is to calculate your carbon footprint. There are many carbon calculators available now that will help you calculate your carbon footprint and buy carbon offsets. For a rating of carbon footprint calculators, see OPW’s website at: http://www.oregonpeaceworks.org/site/index.php?option=content&task=view&id=3148&Itemid=262.
Offset Quality
The critical thing when investing in carbon offsets is to research the organization and the projects you will be funding. All good offset providers should deliver real, independently-verified emission reductions, and many of them bring a wealth of benefits to the communities in which they occur. Sustainable development and improved health are among such benefits, aside from the reduction in global warming gasses.
Industry Standards
There are now carbon offset standards that the leading offset providers are following in their emission reduction projects. They set out to ensure the tons people purchase are actually delivering what the organization promises, to monitored and verified standards. The most common standards you find associated with a carbon offset are:
•   The Gold Standard (supporting both CDM and Voluntary Markets)
•   The Voluntary Carbon Standard (VCS)
•   The Clean Development Mechanism (CDM)
•   VER+ (Developed by TÜV SÜD (a U.N. approved regulatory body)
The industry now has a new regulatory body called ICROA (the International Carbon Reduction and Offset Alliance), providing leadership and a unified voice advocating for rigorous industry standards.
Carbon Offset Providers
For an independent look at some of the main carbon offset providers, independent research by organizations like Clean Air http://bit.ly/CleanAir) , Cool Planet (http://bit.ly/CoolPlanet) or a recent report by Which? (http://bit.ly/1eOjYk) on carbon offset providers. Some of those mentioned include:
•   Brighter Planet (Middlebury, VT USA)
•   Blue Ventures Carbon offset (London, U.K.)
•   Carbon Clear (London, U.K.)
•   Climate Care (Oxford, U.K.)
•   Equiclimate
•   The World Land Trust (Suffolk, U.K.)
•   Climate Friendly (Sydney, Australia)
Why Offset?
Climate change is happening now, right in front of our eyes. The weather is changing, the Arctic is circumnavigable for the first time in human history, and scientific consensus is that it is humans who have tipped the balance. It is our responsibility to correct our fossil-fuel driven emissions and reduce and offset today. Φ
This information came from http://green.wikia.com/wiki/Carbon_offset .