Large carbon dioxide plumes with concentrations up to 45 ppm above ambient levels were measured about 15 km downwind of the Prudhoe Bay, Alaska major oil production facilities, located at 70 degrees N Lat, above the Arctic Circle, The measured emissions were 1.3 x 10(3) metric tons (C) hour(-1) (11.4 x 10(6) metric tons (C) year(-1)), six times greater than the combustion emissions assumed by Jaffe and coworkers in J. Atmos. Chem. 20 (1995), 213-227, based on 1989 reported Prudhoe Bay oil facility fuel consumption data, and four times greater than the total C emissions reported by the oil facilities for the same months as the measurement time periods. Variations in the emissions were estimated by extrapolating the observed emissions at a single altitude for all tundra research transect flights conducted downwind of the oil fields. These 30 flights yielded an average emission rate of 1.02 x 10(3) metric tons (C) hour(-1) with a standard deviation of 0.33 x 10(3). These quantity of emissions are roughly equivalent to the carbon dioxide emissions of 7-10 million hectares of arctic tussock tundra (Oechel and Vourlitis, Trends in Ecol. Evolution 9 (1994), 324-329).