The comma-delimited files hpms_emissions_1km.csv and hpms_emissions_point1degree.csv contain annual CO2 emissions in metric tons for the on-road sector in Massachusetts. Emissions for each year are reported in separate columns as CO2_XXXX where XXXX is the year. Annual vehicle miles travelled (AVMT) are reported similarly for each grid cell. //////////// Coordinates for the 1 km grid are based on the projection: NAD1983 State Plane Massachusetts Mainland FIPS 2001 Lambert Conformal Conic Projection. For the 1km x 1km grid cells, the columns MinX, MaxX, MinY, MaxY, CenterX, CenterY provide the projected coordinates in meters for the location of each grid cell. For the 0.1 degree x 0.1 degree grid cells, the columns MinX, MaxX, MinY, MaxY, CenterX, CenterY provide the geographic coordinates in decimal degrees for the location of each grid cell. //////////// In both files, grid cells have been clipped using ArcGIS to the borders of Massachusetts, as emissions from neighboring states were not included in these calculations. As a result, the area of each grid cell is not necessarily one square kilometer or one square degree. The column "area_km2" provides the area in square kilometers of the CLIPPED grid cell. The state boundary shapefile used to clip the grid cells is available here: http://www.mass.gov/mgis //////////// Attributes of the feature classes in the file geodatabase hpms_emissions.gdb are identical to those in the .csv files.