BEACO2N is a new approach to observing atmospheric gases over an urban area. Instead of using a small number of extremely sensitive instruments to measure a large area, we blanket interesting locations with a high density network of instruments, with each instrument representing a network “node.” Individually, measurements from these nodes are of moderate quality, but when taken together as a network produce an accurate, highly resolved picture of real-time pollutant concentrations. Each node measures carbon dioxide, a major anthropogenic (human-influenced) contributor to climate change, and reports back to this site where the collected data is publicly available for viewing and download. The nodes also collect data on nitrogen oxides, ozone, carbon monoxide, and particulate matter which are indicators for the overall air quality of an area, and may be useful for tracing the origins of CO2 emissions. CO2, CO, and aerosol data are available for download via this site. Data for other species is not yet ready for public viewing, but will be added to the site soon.