Recommending you the highly rated Carbon Offsets Providers

1. Highest level of verification and project types - atmosfair

Summary: Germany, Non-profit, US$ 34 per tonne, 80% cost-efficiency; all CDM projects -biogas, hydro and solar, and two are Gold Standard)
Suitable for: air-travel carbon offsetting ( the only service they provide so far).

2. Highest performance/price ratio - Carbon Offsets Ltd.

Summary: UK, for-profit, US$ 20 for CDM, US$7 for VER; 2 projects in total: wind and energy efficiency.
Suitable for: individual offsets: home, vehicles, flight and also business.

3. Highest cost-efficiency - PURE

Summary: UK, non-profit, US$ 22 per tonne, at least 100% to projects; 4 CDM projects, of which one is Gold Standard.
Suitable for: UK residents because the calculations are based on UK situation, especially good for annually carbon budgeting, for house, vehicles, flights.

4. Most promising and lowest price - Carbonfund.org

Summary: US non-profit, US$ 5.5/tonne, 12 projects, wind, solar, biogas, reforestation, energy efficiency,etc.
Suitable for: Having the intention of offsetting while thinking of paying a lower price.

Here are the providers which I consider they are good, at least among the best of all the providers; my major criteria are the project types, cost-efficiency, verification, and price. Below are the details about my findings, after researching 75 carbon offsets providers.

1. The price of carbon offsets from companies will not usually higher than those from non-profit organisations, mostly depending on project types. But almost all the companies will mix the projects which have higher verification (eg. CDM) with the lower standard ones to sugar what they have and obviously compromise the price. For example, the CarbonNeutral Ltd. have 28 projects in total, of which only 2 are CDM projects, but they boast a lot on how credible their projects are and push their price as high as US$ 21.15 (21 Feb 2008, ECB).

2. As for the cost-efficiency report, only 11 out of 47 companies have it, with an average of 70%, which means if you pay US$100 for the credits, 70 will get into the project. For non-profit ones, 14 out of 28 have the cost-efficiency reports, on average 84% of you money will flow to projects.

3. Not all of the non-profit providers are as good as they seem, some of them are the branches of a certain corporate group; sometimes their websites are not convenient for customers and have less options than the for-profit counterparts.