Survey of Energy Resources 2007
Balance of Peat Usage and Life-Cycle Analysis
The total area of peatlands in Europe is estimated to be 514 882 km2. Agriculture has been the main user of peatlands, with an estimated 125 000 km2 of peatlands used from ancient times. Forestry is the second largest user (Joosten and Clarke, 2002). The total production area for fuel peat in the EU amounts to 1 750 km2 (0.34% of the total peatland area). The total annual use of energy peat has amounted to 12 million delivered tonnes of peat (4 million tonnes of carbon) during recent years (Paappanen, Leinonen and Hillebrand, 2006).
The world's annual peat harvest is equivalent, according to Joosten and Clarke (2002), to about 15 million tonnes of carbon. The present sequestration rate of carbon in all mires of the globe is estimated to be 40-70 million tonnes annually (Joosten and Clarke, 2002), thus exceeding the annual use of peat 3 to 6 times. Peat extraction and peat accumulation are in balance.
A target for further research is how much peat is lost through decomposition on peatlands converted to agriculture and forestry. This is a unique question and every country differs from all others. Finland can be taken as an example: the Geological Survey of Finland studied Finnish peat reserves and found that the country's peat resources in the year 2000 equalled those of 1950, despite widespread use for agriculture and forestry in the intervening period (Turunen, 2004). Furthermore, Finland is a leading country in the industrial use of peat and its peatlands have also been used for the construction of water reservoirs and as a basis for road infrastructure. In spite of such use, Finland's peat carbon stocks are in balance.
Many peatlands in Europe, which were drained and used for agriculture and forestry in the past, are now sources of greenhouse gases, owing to degradation and oxidation of the unsaturated peat layer. If these areas are not significant sources of food or other income for local people, they could be used for peat production and afterwards transformed relatively easily into carbon sinks. This could be done by restoring them to peat-forming mires, by reclaiming them as forests or by planting energy crops. These types of carbon sink will be needed in coming decades. The possibility of reusing energy peat production sites as new carbon sinks constitutes another difference between peatlands and fossil-fuel producing coal mines and oil wells. This difference is clearly shown in life-cycle analyses.
The concept of life-cycle analysis has been used to compare the climate impact of the use of peat as fuel, starting from various peatland types and ending the cycle with different after-use alternatives. A recent report by the VTT Technical Research Centre of Finland (Kirkinen, Hillebrand and Savolainen, 2007) concludes that the climate impact of peat per energy unit is, over a 300 years' perspective, about 10% of the impact of coal, if the peat is produced from former agricultural areas, and rather more than half the impact of coal, if peat is produced from fertile areas drained for forestry. Similar and even lower climate impact is reported by Holmgren and Zetterberg (2005).