Carbon neutrality, or having a net zero carbon footprint, refers to achieving net zero carbon emissions by balancing a measured amount of carbon released with an equivalent amount sequestered or offset, or buying enough carbon credits to make up the difference. It is used in the context of carbon dioxide releasing processes associated with transportation, energy production, and industrial processes such as production of carbon neutral fuel. The carbon neutrality concept may be extended to include other greenhouse gases (GHG) measured in terms of their carbon dioxide equivalence (e) —the impact a GHG has on the atmosphere expressed in the equivalent amount of CO2. The term “climate neutral” reflects the broader inclusiveness of other greenhouse gases in climate change, even if CO2 is the most abundant, encompassing other greenhouse gases regulated by the Kyoto Protocol, namely: methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulphur hexafluoride (SF6). Both terms are used interchangeably throughout this article. The best practice for organizations and individuals seeking carbon neutral status entails reducing and/or avoiding carbon emissions first so that only unavoidable emissions are offset. Carbon neutral status is commonly achieved in two ways: Balancing carbon dioxide released into the atmosphere from burning fossil fuels, with renewable energy that creates a similar amount of useful energy, so that the carbon emissions are compensated, or alternatively using only renewable energies that don’t produce any carbon dioxide (also called a post-carbon economy). Carbon offsetting by paying others to remove or sequester 100% of the carbon dioxide emitted from the atmosphere – for example by planting trees – or by funding ‘carbon projects’ that should lead to the prevention of future greenhouse gas emissions, or by buying carbon credits to remove (or ‘retire’) them through carbon trading. While carbon offsetting is often used alongside energy conservation measures to minimize energy use, the practice is criticized by some. The concept may be extended to include other greenhouse gases measured in terms of their carbon dioxide equivalence. The phrase was the New Oxford American Dictionary’s Word Of The Year for 2006.