Ilkka Savolainen

Towards a standard methodology for greenhouse gas balances of bioenergy systems in comparison with fossil energy systems

In this paper, which was prepared as part of IEA Bioenergy Task XV (“Greenhouse Gas Balances of Bioenergy Systems”), we outline a standard methodology for comparing the greenhouse gas balances of bioenergy systems with those of fossil energy systems. Emphasis is on a careful definition of system boundaries. The following issues are dealt with in detail: time interval analysed and changes of carbon stocks; reference energy systems; energy inputs required to produce, process and transport fuels; mass and energy losses along the entire fuel chain; energy embodied in facility infrastructure; distribution systems; cogeneration systems; by-products; waste wood and other biomass waste for energy; reference land use; and other environmental issues. For each of these areas recommendations are given on how analyses of greenhouse gas balances should be performed. In some cases we also point out alternative ways of doing the greenhouse gas accounting. Finally, the paper gives some recommendations on how bioenergy systems should be optimized from a greenhouse-gas-emissions point of view.

Project-based greenhouse-gas accounting: guiding principles with a focus on baselines and additionality

Project-based Greenhouse Gas Accounting : guiding principles with a focus on baselines and additionality

Greenhouse Impact Due to the Use of Combustible Fuels: Life Cycle Viewpoint and Relative Radiative Forcing Commitment

Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels.

Development of an Integrated Model for the Assessment of Acidification in Finland

An integrated model to consider the future development of acidifying emissions and their impacts on forest soils and lakes is being prepared in close collaboration with several Finnish research institutes and IIASA. The model system (HAKOMA) covers SO2 and NOx emissions from energy use, industrial processes, and transportation, and also NH3 emissions from agriculture, animal farming, and industry. Future emissions are estimated on the basis of different scenarios for energy, traffic, industry and agriculture and on the basis of alternative reduction strategies.

The role of carbon sequestration and the tonne-year approach in fulfilling the objective of climate convention

Abstract Carbon can be sequestered from the atmosphere to forests in order to lower the atmospheric carbon dioxide concentration. Tonne-years of sequestered carbon have been suggested to be used as a measure of global warming impact for these projects of finite lifetimes. It is illustrated here by simplified example cases that the objective of the stabilisation of the atmospheric greenhouse gas concentrations expressed in the UN Climate convention and the tonne-year approach can be in contradiction. Tonne-years generated by the project can indicate that carbon sequestration helps in the mitigation of climate change even when the impact of the project on the CO2 concentration is that concentration increases. Hence, the use of the tonne-years might waste resources of fulfilling the objective of the convention. The studied example cases are closely related to the IPCC estimates on global forestation potentials by 2050. It is also illustrated that the use of bioenergy from the reforested areas to replace fossil fuels can in the long term contribute more effectively to the control of carbon dioxide concentrations than permanent sequestration of carbon to forests. However, the estimated benefits depend on the time frame considered, whether we are interested in the decadal scale of controlling of the rate of climate change or in the centennial scale of controlling or halting the climate change.

A comment to “Large-scale bioenergy from additional harvest of forest biomass is neither sustainable nor greenhouse gas neutral”: Important insights beyond greenhouse gas accounting

RYAN M. BR IGHT * , FRANCESCO CHERUB IN I * , RASMUS ASTRUP † , NE I L B IRD ‡ , ANNETTE L . COWIE § , MARK J . DUCEY ¶ , GREGG MARLAND k, K IM P INGOUD* * , I LKKA SAVOLA INEN* * and ANDERS H. STRØMMAN* *Industrial Ecology Program, Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway, †Department of Forest Resources, Norwegian Forest and Landscape Institute, Ås, Norway, ‡Joanneum Research, Resources, Institute for Water, Energy and Sustainability, Graz, Austria, §Department of Primary Industries, Rural Climate Solutions, University of New England/NSW, Armidale, Australia, ¶Department of Natural Resources & the Environment, University of New Hampshire, Durham, N. H, USA, kResearch Institute for Environment, Energy, and Economics, Appalachian State University, Boone, North Carolina, USA, **VTT Technical Research Center of Finland, Espoo, Finland

Bioenergy and the forest industry in Finland after the adoption of the Kyoto protocol

Abstract In Finland the percentage of biomass fuels of total primary energy supply is relatively high, close to 17%. The share of biomass in the total electricity generation is as much as 10%. This high share in Finland is mainly due to the cogeneration of electricity and heat within forest industry using biomass-based by-products and wastes as fuels. Forest industry is also a large user of fossil-based energy. About 28% of total primary energy consumption in Finland takes place in forest industry, causing about 16% of the total fossil carbon dioxide emissions. The Kyoto protocol limits the fossil CO2 and other greenhouse gas emissions and provides some incentives to the Finnish forest sector. There are trade-offs among the raw-material, energy and carbon sink uses of the forests. Fossil emissions can be reduced e.g. by using more wood and producing chemical pulp instead of mechanical one. According to the calculation rules of the Kyoto protocol Finnish forests in 2008–2012 are estimated to form a carbon source of 0.36 Tg C a−1 due to land use changes. Factually the forest biomass will still be a net carbon sink between 3.5 and 8.8 Tg C a−1. Because the carbon sinks of existing forests are not counted in the protocol, there is an incentive to increase wood use in those and to decrease the real net carbon sink. Also the criteria for sustainable forestry could still simultaneously be met.

Assessing the impact of CO2 emission control scenarios in Finland on radiative forcing and greenhouse effect

Carbon dioxide emission reduction scenarios for Finland are compared with respect to the radiative forcing they cause (heating power due to the absorption of infrared radiation in the atmosphere). Calculations are made with the REFUGE system model using three carbon cycle models to obtain an uncertainity band for the development of the atmospheric concentration.The future emissions from the use of fossil fuels in Finland are described with three scenarios. In the reference scenario (business-as-usual), the emissions and the radiative forcing they cause would grow continuously. In the scenario of moderate emission reduction, the emissions would decrease annually by 1% from the first half of the next century. The radiative forcing would hardly decrease during the next century, however. In the scenario of strict emission reductions, the emissions are assumed to decrease annually by 3%, but the forcing would not decrease until approximately from the middle of the next century depending on the model used. Still, in the year 2100 the forcing would be considerably higher than the forcing in 1990. Due to the slow removal of CO2 from the atmosphere by the oceans, it is difficult to reach a decreasing radiative forcing only by limiting fossil CO2 emissions.The CO2 emissions from fossil fuels in Finland contribute to the global emissions presently by about 0.2%. The relative contribution of Finnish CO2 emissions from fossil fuels to the global forcing due to CO2 emissions is presently somewhat less than 0.2% due to relatively smaller emissions in the past. The impact of the nonlinearity of both CO2 removal from the atmosphere and of CO2 absorption of infrared radiation on the results is discussed.

Greenhouse impact of fossil, forest residues and jatropha diesel: a static and dynamic assessment.

Biofuels have been recognised as one option for mitigating climate change. However, in order to show the sustainability of biomass-based fuels, an assessment of the savings in Greenhouse Gas (GHG) emissions compared to fossil fuels needs to be clearly shown. There are two ways to measure the greenhouse impact of an activity. It can be done statically or dynamically, by using Global Warming Potential (GWP) or Radiative Forcing (RF) respectively. This article compares these two methods for assessing the greenhouse impact and introduces two more rarely discussed and lesser-known raw materials for biodiesel production, forest residues in Finland and jatropha in India, as well as their greenhouse impact compared to fossil fuel from a life cycle perspective. The analyses made with GWP and RF show some differences. Using a time horizon of 100 and 300 years, the magnitude of the greenhouse impact of jatropha biodiesel assessed with GWP and RF differs by only a few percent. When the greenhouse impact of forest residue-based Fischer-Tropsch (FT) diesel was assessed, the difference between the GWP and RF assessment was larger, up to 10%. This is also a reflection of the more accurate calculation possibility of the greenhouse impact with RF in which the exponential and time dependent decay of forest residues can be taken into account. Compared to fossil diesel, the greenhouse impact of jatropha and forest residue-based biodiesel was approximately one-third less, irrespective of the assessment method. This, however, may not be enough to fulfil the requirements of the European Union (EU) on the sustainability of biofuels.

Radiative forcing due to greenhouse gas emissions and sinks in Finland — estimating the control potential

The developed REFUGE computer model is used to assess radiative forcing due to man-induced CO2, CH4, and N2O emissions in Finland. Both the emission history and assumed future control scenarios for emissions and forest carbon sink are considered. CO2 emissions from the use of the fossil fuels cause most of the radiative forcing due to human activities in Finland. Other important contributors to radiative forcing are N2O emissions from agriculture and transportation as well as CH4 emissions from animal husbandry and waste disposal. Radiative forcing in the year 1990 due to the considered Finnish emissions is estimated to be ∼ 3 mW/m2, which is ∼ 0.15% of global radiative forcing (the population of Finland is ∼ 0.09% of the Earths population). Radiative forcing due to emissions resulting from human activities in Finland is increasing, and due to the slow change rates in emission producing activities and the slow removal of CO2 and N2O from the atmosphere, it seems unlikely that radiative forcing will be reduced in the next century to below the 1990 level using emission control. A remarkable additional measure in the control of radiative forcing due to activities in Finland might be to increase carbon storage in the forest ecosystem for some decades and to maintain this storage.