Air quality data from the EPA collected from state, local, and tribal monitoring agencies from across the US.

The Center for International Earth Science Information Network (CIESIN) is a center within the Earth Institute at Columbia University. CIESIN works at the intersection of the social, natural, and information sciences, and specializes in on-line data and information management, spatial data integration and training, and interdisciplinary research related to human interactions in the environment.

WRI is a global research organization that turns big ideas into action at the nexus of environment, economic opportunity and human well-being.
The WRI provides a number of data sets, maps, and data visualizations.

Offers statistical data related to energy sources and environmental topics, such as petroleum, renewable and alternative fuels, coal, energy use in homes and commercial buildings, and more. Also offers basic information on energy related topics.

NOAA's National Centers for Environmental Information (NCEI) is responsible for preserving, monitoring, assessing, and providing public access to the Nation's treasure of climate and historical weather data and information.