Although the burning of fossil fuels
generates most of the potential emissions from most reserves, emissions from production and processing
operations (known as «
upstream emissions») can also be important, depending on the reserve type and technologies used.
According to the Greenhouse Gas Protocol,
upstream categories include: purchased goods and services, capital goods, fuel and energy related activities (not included in scope 1 or scope 2),
upstream transportation and distribution, waste
generated in
operations, business travel, employee commuting and,
upstream leased assets.