Carbon neutral
Being carbon neutral, or carbon neutrality, refers to neutral (meaning zero) total carbon release, brought about by balancing the amount of carbon released with the amount sequestered or offset. Various special interests attempt to promote a use of the term that  refers to carbon reduction, which is clearly not neutral. In this more loose sense, it has two common uses:
- It can refer to the practice of 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 (this last is called a post-carbon economy).
- It is also used to describe the practice, criticized by some, of 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. These practices are often used in parallel, together with energy conservation measures to minimize energy use.
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 Dictionarys Word Of The Year for 2006.

# Becoming carbon neutral
When an individual or an organization sets out to become carbon neutral it is usually achieved by combining the following three steps:
- Limiting energy usage and emissions
From transportation (walking, using bicycles or public transport, avoiding flying, using low-energy vehicles).
From buildings, equipment, animals and processes.
- From transportation (walking, using bicycles or public transport, avoiding flying, using low-energy vehicles).
- From buildings, equipment, animals and processes.
- Obtaining electricity and other energy from a renewable energy source, either directly by generating it (installing solar panels on the roof for example) or by selecting an approved green energy provider, and by using low-carbon alternative fuels such as sustainable biofuels.
- Offsetting the remaining emissions that cannot for the moment be avoided or generated from renewables in a responsible carbon project, or by buying carbon credits.
Being carbon neutral is increasingly seen as good corporate or state social responsibility and a growing list of corporations and states are announcing dates for when they intend to become fully neutral. Some corporate examples include Dell, 
Google, 
HSBC, 
ING Group, 
PepsiCo, and
Tesco.
Events such as the G8 Summit and organizations like the World Bank are also using offset schemes to become carbon neutral. Artists like The Rolling Stones and Pink Floyd have made albums or tours carbon neutral.

# Direct and indirect emissions sources
To be considered carbon neutral, an organization must reduce its carbon footprint to zero.  Determining what to include in the carbon footprint depends upon the organization and the standards they are following.
Generally, direct emissions sources must be reduced and offset completely, while indirect emissions from purchased electricity can be reduced with renewable energy purchases.
Direct emissions include all pollution from manufacturing, company owned vehicles and reimbursed travel, livestock and any other source that is directly controlled by the owner.  Indirect emissions include all emissions that result from the use or purchase of a product.  For instance, the direct emissions of an airline are all the jet fuel that is burned, while the indirect emissions include manufacture and disposal of airplanes, all the electricity used to operate the airline's office, and the daily emissions from employee travel to and from work.  In this case, the power company has a direct emission of greenhouse gas, while the office that purchases it considers it an indirect emission.

# Simplification of carbon neutral standards and definitions
Before an agency can certify an organization or individual as carbon neutral, it is important to specify whether indirect emissions are included in the Carbon Footprint calculation. Most Voluntary Carbon neutral certifiers such as Standard Carbon in the US, require both direct and indirect sources to be reduced and offset.  As an example, for an organization to be certified carbon neutral by Standard Carbon, it must offset all direct and indirect emissions from travel by 1 lb CO2e per passenger mile, and all non-electricity direct emissions 100%.  Indirect electrical purchases must be equalized either with offsets, or renewable energy purchase. This standard differs slightly from the widely used World Resource Institute and may be easier to calculate and apply.
The World Resource Institute, in addition to publishing many tables and help aids for calculating carbon footprints, only requires direct emissions to be reduced and balanced for carbon neutral status, however there is adequate encouragement to include all emissions sources.  With this accounting, there are essentially two levels of Carbon neutral: Either all direct and indirect emissions, or only direct emissions.
Much of the disunity in carbon neutral standards can be attributed to the voluntary nature of carbon offseting and carbon neutrality.
The concept of shared resources also reduces the volume of carbon a particular organization has to offset, with all upstream and downstream emissions the responsibility of other organizations or individuals. If all organizations and individuals were involved then this would not result in any double accounting.

# Carbon-neutral states
In July 2007, Vatican City became the first carbon neutral state in the world, following the politics of the Pope to eliminate global warming. The goal was reached through the donation of the Vatican Climate Forest in Hungary. The forest is to be sized to offset the year's carbon dioxide emissions.
The Central American nation of Costa Rica aims to be fully carbon neutral before 2030. In 2004, 46.7% of Costa Rica's primary energy came from renewable sources, while 94% of its electricity was generated from hydroelectric power, wind farms and geothermal energy in 2006. A 3.5% tax on gasoline in the country is used for payments to compensate landowners for growing trees and protecting forests and its government is making further plans for reducing emissions from transport, farming and industry.