ASSESSING DATA FOR PRECURSORS OF CO2 AND METHANE IN KING COUNTY, WASHINGTON, 1990

Evaluation of policies designed to reduce emissions of global warming gases will require valid data about in-use quantities of these gases p recursors. This article assesses the quality of available data for man y significant precursors of CO2 and methane in King County, Washington which is an area with minimal variations in climate as well as develo pment. Available data support an estimate of 21,000,000 metric tons of CO2-equivalent gases emitted in 1990 from selected precursors. There is also evidence that electricity conservation programs and recycling both reduce CO2 emissions. Requirements for adequate baseline data inc lude constant and valid data definitions as well as monthly time serie s. To evaluate policies over periods of years, databases must be desig ned to withstand frequent and rapid changes in national economies; the y must also permit analysis of consumer choices affecting fossil fuels and other precursors of worming gases. in almost every case, current data do not satisfy these requirements.