National Greenhouse Gas Emissions Inventory 1994 – 1998

With the present updating of the National Greenhouse Emissions Inventory (INGEI) the inventory for 1996 relative to all sectors appointed by the Intergovernmental Panel on Climate Change (PICC) is disclosed. With the exception of the Forestry Sector, it was possible to estimate emissions for other years in the other sectors, from 1994 to 1998. In some of them, emissions for 1992 were presented and emissions for 1990 could be estimated again.

General Perspective

GHG emmissions for 1996 in terms of CO2 equivalent to 100 years 1 were 691,318 Gg, considering only carbon dioxide, methane, and nitrous oxide. From these, 514,048 Gg (74%) account for CO2; 162848 Gg (24%) to methane, and 14,422 Gg (2%) to nitrous oxide (Figure 1).

Figure 1. Percentual Distribution of GHG Emissions for 1996 in Terms of CO2 Equivalent

By sector, and still in terms of CO2 equivalent so that sectors with different gas emissions may be compared (Figure 2), combustion porcesses not involving transport internal combustion engines emitted 219,432 Gg of CO2 equivalent. Transport internal combustion processes emitted 100,159 Gg. The addition of these two, which encompasses energy production and combustion, accounts for 46.2% of emissions. Methane fugitive emissions in oil and natural gas industry were 49,799 Gg (7.2%). Industrial process emissions of these three gases were 43,121 Gg (6.2%). Agriculture and livestock husbandry emitted 55,674 Gg (8.1%). The forestry sector emitted 161,422 Gg of CO2 equivalent (23.4%), which makes it the second major source. Urban and industrial waste management contributed with 61,710 Gg (8.9%).

Industrial process and waste sectors showed a significant increase, both in terms of volume as in terms of percentual participation. This is partly due to the fact that some sources were not included in the 1990 Inventory, as well as to changes in methodology. Moreover, the waste management sector showed a noticeable increase in the number of sanitary landfills and waste water treatment plants as a result of the implementation of local environmental regulations.

On the other hand, the agriculture and livestock sector shows some stagnation in its participation. Structural changes in the economy may be responsible of this, as well as the long drought of the 1990s, which was worsened by the severe 1998-event “El Niño”.

Figure 2. Emission Distribution by Sectors in Terms of CO2 Equivalent.

Because of its capability to absorb infrared radiation, one gram of methane is equivalent to 21 grams of carbon dioxide in a time span of 100 years, considering its molecular properties and its residence time in the atmosphere. One gram of nitrous oxide is equivalent to 310 grams of carbon dioxide (IPCC, 1996).