Oxford Dictionary Term of the Year

Carbon neutral is it. Climate change is a serious problem, caused primarily by the carbon dioxide released from burning fossil fuels like oil, coal, and gas. But there are things we can do about it - like choosing to go carbon neutral. Going carbon neutral is an easy way to take responsibility for the greenhouse gas emissions we create every time we drive our cars, take a plane, or turn on our computers. It's based on the principle that, since climate change is a global problem, an emission reduction made elsewhere has the same positive effect as one made locally. Here's how it works: if you add polluting emissions to the atmosphere, you can effectively subtract them by purchasing 'carbon offsets'. Carbon offsets are simply credits for emission reductions achieved by projects elsewhere, such as wind farms, solar installations, or energy efficiency projects. By purchasing these credits, you can apply them to your own emissions and reduce your net climate impact.
In addition, by voluntarily calculating and assigning a cost to your carbon emissions, we can begin to prepare for the inevitability of an economy in which carbon dioxide and other greenhouse gases are regulated and taxed. Whether you are a business or an individual, this is an important step towards managing your carbon emissions efficiently and identifying potential for reductions and savings. Purchasing high quality carbon offsets from projects such as wind farms also helps support the transition to a sustainable energy economy by providing an additional source of revenue to developers of renewable energy.

While voluntary offset programs should not be seen as a substitute for comprehensive government regulations to reduce greenhouse gases (e.g. through implementation of the Kyoto Protocol), they are a step in the right direction, and an opportunity to demonstrate leadership on climate change.

Carbon offsets also offer flexibility, as you can choose to offset just one - or all - of your major emission sources. For example, you can purchase carbon offsets to mitigate the emissions from your air travel, automobile use, or home heating. If you wish to offset the emissions from electricity, you can use either carbon offsets or a special product known as a "Renewable Energy Certificate" (REC), which is like purchasing renewable energy.
Source: David Suzuki Foundation website.