Ekologiska fotavtryck för koldioxidutsläpp för Stockholms län, Norrbottens län och Stockholms läns landsting : En kritisk metodgranskning baserad på kvantitativa data

Sammanfattning: Human existence and welfare depend on functional ecosystems. Ecosystems are critical to sustain life-support services for human well-being. One method that visualizes that humanity requires ecosystem services for resource consumption and assimilation of produced waste is ecological footprints. This study focuses on the ecosystem service carbon sequestering. A quantification of this ecosystem service showed the potential for accumulation of carbon in different ecosystems in Stockholm and Norrbotten County for the years of 1995 and 2004. This study also provides an estimate of the ecosystem area that is appropriated to accumulate all carbon from total carbon dioxide emissions in Stockholm and Norrbotten County respectively. The appropriated ecosystem area represents the ecological footprint. The ecological footprint is also calculated for Stockholms läns landsting`s total carbon dioxide emissions in 2004. The total potential for accumulation of carbon is lower in the ecosystems in Stockholm County in 2004 than in 1995 and the corresponding figure for Norrbotten County has increased. The results indicate that the total potential for carbon accumulation in Stockholm County was approximately 427 kton C year-1 in 1995 and 352 kton C year -1 in 2004. In 1995 the ecosystems in Stockholm County could assimilate 26% of the county’s total emissions whereas the figure for 2004 was 21%. In Norrbotten County, the total potential for accumulation was approximately 2 824 kton C year -1 in 1995 and 2 983 kton C year -1 in 2004. The ecosystem area that is appropriated to assimilate total emissions of carbon dioxide was smaller in 2004 than in 1995 in Stockholm County and larger in Norrbotten County. The ecological footprint for total carbon dioxide emissions in Stockholm County was 12 696 km2 in 1995 and 12 506 km2 in 2004. The corresponding estimate for Norrbotten County indicate that the ecological footprint for total carbon sequestering was 14 457 km2 in 1995 and 32 146 km2 in 2004. The result shows that both regions require large areas of ecosystem to absorb total emissions of carbon dioxide. Stockholms läns landsting´s ecological footprint was 409 km2, which corresponds to 3.3 % of the County’s total ecological footprint. Stockholm County depends on ecosystem areas outside the region for assimilation of the region’s total emissions of carbon dioxide. According to the results Norrbotten County is self-sufficient with regard to the ecosystem service carbon accumulation. This study also includes a discussion of the advantages and limitations of the ecological footprint as a methodology. The received results serve as the starting point for this discussion. Ecological footprints are pedagogic and communicative indicators and can therefore reach out to a broad audience which is a great advantage with the method. It is a static measure and is therefore incapable of giving any presages. Ecological footprints do not take the dynamics and complexity of ecosystems into account and can therefore not provide any information about the possibilities for ecosystems to deliver ecosystem services at the same quality and quantity in the future. The method does not take socio-economic factors into consideration. For these reasons, ecological footprint should not be used as an indicator for sustainability. On the other hand, ecological footprint can illustrate why an ecologically sustainable development is necessary by visualizing that human welfare and existence rely on functional ecosystems.