The rules of VEC are designed to seek something that can remove greenhouse gases ("GHGs") in a material way to contribute to the stability of the Earth's climate.

The rules aren’t just concerned with the GHG removal itself. Our criteria also give due consideration to the other factors necessary if something is to be a safe and sustainable way of taking GHGs out of the air at a meaningful scale.

The Terms and Conditions of the Virgin Earth Challenge, including the Assessment Criteria can be found here (217Kb PDF).