Carbon Dioxide Emissions Sources and History

Total energy use at Williams has increased steadily since 1991 (see the red line in the following graph). Emissions have also increased steadily, but have not always matched the total energy use. The sections of the total energy use line that are blue are years when total energy use has increased, but emissions have either remained steady or decreased. Emissions from the different fuels Williams uses are presented as cummulative areas on the graph. The total emissions are the sum of all of the lower areas, represented by the top of the highest fuel area (the top of the grey "Solid Waste" area).

The reason that total energy use increased from 1997 to 1998 while emissions decreased slightly is that Williams burned more natural gas and less #6 fuel oil in that time period. The Williams heating plant can burn either natural gas or #6 fuel oil, and natural gas has much lower C02 emissions than #6 fuel oil.