What are offsets?   Why should you offset?   Why shouldn't you offset?   How do you judge offset quality?

What are carbon offsets?

Carbon offsets are the reduction of greenhouse gas emissions somewhere else in order to help "offset" one's own emissions. Individuals and organizations can buy offsets from a variety of offset providers, who invest that money in renewable energy, energy conservation projects, etc.

Providers sell offsets by the ton of CO2 emissions mitigated, and typically charge US$10-20/ton. The average American emits 20 tons of CO2 per year (about $300 to offset); the average European 10 tons (~$150), and the average Indian 1.2 tons (~$18).

Four reasons to offset yourself:

  • Help reduce the net impact of emissions that are difficult or impossible to stop generating
  • Support big projects that have more impact than small personal changes, via pooled investments
  • Convince reluctant leaders that citizens are willing to associate a cost with caring for their environment
  • If you buy enough offsets, you can have a net negative carbon footprint; there's no reason to stop at zero

Two reasons to avoid it:

  • Offsets don't give you a license to increase your personal greenhouse gas output, just as donating to an anti-domestic-violence NGO doesn't give you an excuse to engage in domestic violence.
  • Buying poor-quality offsets is counterproductive, wasting money and harming real efforts to measure and manage emissions. If you buy offsets, pick a top-quality provider.

How to compare offsets:

Does it do what it claims?
Is it funding only projects that wouldn't have been funded otherwise? Are CO2 reductions permanant?
How can you tell?
Good offsets should be verifiable by 3rd parties, and tracked end to end. Transparency is critical.
How much does it cost?
All else being equal, cheaper offsets give a bigger bang for the buck.