MARKETS AND FINANCE Bioenergy International Bioenergy Internat ional NNoo 8811,, 55--22001155 3399 Public interest in peatlands and peat has grown rapidly, in part due to its seemingly ambiguous role as a carbon sink and greenhouse gas (GHG) source. Indeed the International Peat Society (IPS) made a subtle yet significant name change to International Peatlands Society. In BioOpinion Claes Rülcker, IPS Executive Board Member, Chief Executive Officer (CEO) for the Swedish Peat Producers Association and the Swedish Peat Research Institute clarifies the issues. Can you describe what peat or turf is? – Peat or turf is generally defined as a heterogeneous mixture of dead and partially decomposed plant material that has accumulated sedentarily in an anaerobic water-saturated environment, a wetland. Peatlands are estimated to cover roughly 3 percent of the global land area and represent 50 to 70 percent of global wetlands. So all peatlands are wetlands but not all wetlands are peatlands. A wetland is an area that is saturated by water at a frequency and for a duration sufficient to support vegetation typically adapted for life in saturated soil conditions. As a result wetlands often display high environmental conservation values for a range of flora and fauna. A peatland on the other hand is an area with or without vegetation with a naturally accumulated peat layer at the surface, a mire is a peatland where peat is currently being formed. Thus a key distinguishing feature of a peatland is its capacity to accumulate this dead and partially decomposed biomass sedentarily. This accumulating capacity is a very crucial point. Peatlands are found in many countries around the world, those with the largest accumulation rates are in areas where the temperature is high enough to support plant growth but low enough to slow microbial decomposition, and these conditions are generally found in the northern hemisphere. From a commercial perspective peatland is defined as having a peat layer depth, excluding vegetation, of at least 20 cm when drained or 30 cm undrained. Once harvested and dried peat is used for a variety of purposes: animal bedding, potting medium, whisky flavouring, water filtration and as fuel. In fact research in Finland and Sweden suggest peat works well as a technical fuel to co-fire in biomass facilities due to its chemical properties. It is this ”accumulating capacity” that makes peat a renewable biomass source? – Absolutely, because contrary to widespread belief, a peatland that has been drained and harvested can be restored back into an accumulating mire, just as you would replant a forest after a final harvest. Why then the disagreement amongst agencies on peat; the Finnish government views it as ”slowly renewable” and the Intergovernmental Panel on Climate Change (IP CC) changed its classification, from ”solid fossil fuel” to ”peat” in 2006? – The peatland ecosystem is one of the most efficient carbon sinks on the planet as the annual rate of dead biomass accumulation, peat formation, is larger than the annual rate of decomposition. The issue is time and sustainability given that the rate of peat formation is slow, the global average rate is about 1 mm per annum. As a result many critics regard peat as a fossil fuel, which to my mind is entirely incorrect for reasons I’ve described. The basis for this view are fears that the rate of peat harvesting and usage in some industrialised regions far exceeds the rate of formation compounded by the fact that only 20-30 percent of exhausted peatlands in these regions have been restored. Whilst the long-term sustainable use of peat – ensuring that harvesting rates are well below formation rates – is an extremely important issue that the IPS takes very seriously, it still does not make peat a fossil fuel any more than deforestation makes wood a fossil fuel. Nonetheless critics argue peat use destroys peatland that in itself has high conservation values? – There is no doubt that peat harvesting per se may seem an invasive and destructive activity. As an international multi-stakeholder organisation with representatives from all aspects of the peat value chain including conservation, IPS recognises that the biggest criticism on peat use is how peatlands are affected. Keeping it in perspective approximately 7 percent of the global peatland area have been disturbed, drained for conversion into land for agriculture, forestry and urbanisation as well as peat harvesting. A great deal of ongoing research work by IPS is directed at understanding the various hydrological, chemical and biological mechanisms in different peatlands, restoration and rehabilitation of disturbed peatlands, greenhouse gas (GHG) emissions, as well as drafting policy and legislative frameworks for permitting, operation and restoration to minimise environmental impacts. Can you explain greenhouse gas (GHG) leakage from drained peatlands? – In Europe peatland drainage started in earnest roughly from the mid 1800’s onwards. It is these peatlands where the peat layer has not been removed that leak enormous amounts of greenhouse gases (GHGs), primarily as carbon dioxide, as the peat oxidates in contact with the air. A study commissioned by the Peat Research Institute found that these drained peatlands, used in agriculture and forestry, are Sweden’s largest single carbon emitter. According to the study the only reliable methods to stop these GHG emissions is to either put the land back under water or remove the peat layer. My view is that we should use the peat from these drained peatlands and displace fossil fuels before reverting them back to agriculture, forestry or wetlands so carbon sequestration can begin again. Within IPS we plan to commission a larger EU-wide study to quantify this leakage. Text & photo: Alan Sherrard BI81/4920/AS BioOpinion: Claes Rülcker - CEO, Swedish Peat Producers Association “This accumulating capacity is a very crucial point”
Bioenergy no 5 September 2015
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