Few companies have actually attained Climate Neutral Certification, applying to a rigorous review process and establishing that they have achieved absolute net zero or better impact on the world's climate. Another reason that companies have difficulty in attaining the Climate Neutral Certification is due the lack clear guidelines on what it means to make a carbon neutral development. Shaklee Corporation became the first Climate Neutral certified company in April 2000. The company employs a variety of investments, and offset activities, including tree-planting, use of solar energy, methane capture in abandoned mines and its manufacturing processes. Climate Neutral Business Network states that it certified Dave Matthews Band's concert tour as Climate Neutral. The Christian Science Monitor criticized the use of NativeEnergy, a for-profit company that sells offset credits to businesses and celebrities like Dave Matthews.