This Article provides a general introduction to what is commonly referred to as “big data,” and offers an outline of over 60 initiatives underway in the public and private sectors to use big data to forward environmental protection. This initial survey is not intended to provide a comprehensive list of all efforts currently underway, but instead to illustrate the range of initiatives and approaches used by government agencies, nongovernmental organizations, and industry. The Article also discusses some of the legal and policy concerns associated with the use of big data to advance environmental protection.