Task 25: Greenhouse Gas Balances of Bioenergy Systems
8-11 September 1998 – Spa Hotel Rantasipi Eden
Jointly organized by
P.O. Box 1606
FIN-02044 VTT (Espoo), FINLAND
A-8010 Graz, AUSTRIA
The primary goal of IEA Bioenergy Task 25 (“Greenhouse Gas Balances of Bioenergy Systems”) is to investigate all processes involved in the use of bioenergy systems, on a full fuel-cycle basis, with the aim of establishing overall greenhouse gas balances.
The Task 25 workshop in Nokia, Finland, is part of a series of workshops taking place within Task 25 and the predecessing Task XV every 6 to 12 months. For more detailed information on the Task, and on previous workshops, see the other contents of this site.
Altogether, six events will take place during this workshop, some of them jointly with IEA Bioenergy Task 18 (“Conventional Forestry Systems for Bioenergy”):
TUESDAY, 8 SEPTEMBER 1998
WEDNESDAY, 9 SEPTEMBER 1998
J. Richardson and J. Spitzer
Site preparation techniques in energy and fiber plantations to sequester carbon
M. Buford and B. J. Stokes (USDA Forest Service/USA)
Framework for assessing the contribution of soil carbon to New Zealand CO2 emissions
C. T. Smith*, J. Ford-Robertson*, K. R. Tate, and N. A. Scott (* New Zealand Forest Research Institute Limited/New Zealand)
Towards future European forest carbon budget (LTEEF-II project)
A. Pussinen*, T. Karjalainen*, J. Liski*, and G.-J. Nabuurs** (* European Forest Institute/Finland, ** Institute for Forestry and Nature Research – ibn-dno/The Netherlands)
Long-term effects of whole-tree harvesting on carbon pools in coniferous forest soils
B. Olsson (Swedish Agricultural University/Sweden)
Whole-tree harvesting as a means to avoid nitrogen over-loading in forest ecosystems
H. Eriksson, J. Vinterbaeck, M. Parikka, and B. Hektor (Swedish Agricultural University/Sweden)
Forestry, climate change and carbon in soils
J. Liski (European Forest Institute/Finland)
The role of forest growth models in assessments of carbon balance and environmental impact of fibre and bioenergy production systems
R. Matthews (Forestry Commission Research Agency/UK)
Discussion of future directions for Task 18 and Task 25 collaboration
THURSDAY, 10 SEPTEMBER 1998
The Finnish forestry in light of Kyoto Protocol
H. Granholm (Finnish Ministry of Agriculture and Forestry/Finland)
GHG emissions and possibilities for reduction using fuelwood and forest waste for energy in Croatia
V. Jelavic* and J. Domac** (* EKONERG Holding/Croatia; ** Energy Institute “Hrvoje Pozar”/Croatia)
Role of forestry and biomass production for energy in reducing net GHG emissions in Finland – assessment concerning the history and future
I. Savolainen*, T. Karjalainen**, K. Pingoud*, and J. Liski** (* VTT/Finland; ** European Forest Institute/Finland)
Fuelwood in Europe for Environment and Development Strategies (FEEDS)
P. Ballaire (Ademe/France)
Application of the Unified Wood Energy Terminology (UWET) for the collection, compilation and presentation of wood fuel data and
FAO Task Force on Dendroenergy and CO2 Substitution and Sequestration
M. Trossero (FAO Forestry Department/Italy)
Large-scale power generation using forestry and wood industry by-products
J. Ford-Robertson (New Zealand Forest Research Institute Limited/New Zealand)
Forestry strategies – temporary or permanent solution in carbon mitigation
P. Kauppi (Helsinki University/Finland)
Bioenergy and power production; power company’s perspective
A. Heikkinen (IVO Power Company/Finland)
Global land-use and land-use change with respect to future bioenergy scenarios
D. O. Hall or T. Johansson (yet to be confirmed, title tentative)
Project-based greenhouse gas accounting: guiding principles with focus on baselines
L. Gustavsson (Lund University/Sweden)
The role of biomass in greenhouse gas mitigation (IEA Bioenergy draft position paper)
J. Spitzer (Joanneum Research/Austria)
FRIDAY, 11 September 1998
Elaboration of an IEA Bioenergy position paper on the role of bioenergy in the light of the targets set in the Kyoto Protocol and the upcoming 4th Conference of the Parties to the UN Framework Convention on Climate Change, Buenos Aires, 2-13 November 1998 (basis: draft position paper).
Proceedings of the Workshop
Between COP3 and COP4: The Role of Bioenergy in Achieving the Targets Stipulated in the Kyoto Protocol
R. Madlener and K. Pingoud (eds.)
The future demands on forest lands are a concern because of reduced productivity, especially on inherently poor sites, sites with long-depleted soils, or those soils that bear repeated, intensive short rotations. Forest are also an important carbon sink, and when well managed, can make even more significant contributions to sequestration and to reduction of green house gases. This paper looks at the use of forest biomass as a carbon sink and as a source of nutrients for enhancing or restoring site productivity. An hypothesis that wood incorporated into the soil will store carbon for an unknown length of time and an example analysis using logging residues is presented. An overview of a field study conducted to evaluate the use of mulching and tilling as a site preparation tool for incorporating biomass into the soil is also presented.
Soils contain the largest amount of carbon (C) in the terrestrial biosphere, so changes in soil C resulting from land management must be considered in estimating national C balances. New Zealand has developed a framework for estimating the 1990 soil C baseline for three soil depths (0-0.1 m, 0.1-0.3 m, 0.3-1.0 m) and future changes in soil C based on the premise that (1) IPCC soil groups, (2) climate groupings based on USDA Soil Taxonomy soil moisture and soil temperature regimes, and (3) land use are the major factors determining the C content of New Zealand soils. These three factors were the basis for deriving 166 cells from a matrix of the key 18 Soil/Climate Groups and 11 Land Use Classes, minus cells that were not found in New Zealand, which were condensed down to 39 “key” cells, which contribute significantly to the soil C content of New Zealand. The soil programme is linked to efforts to determine C in indigenous forests and scrub. For each of three soil depths, each cell is currently represented by varying numbers of sample points, based on historical data and new field samples. Current data in the system being developed provides an estimate of baseline soil C for New Zealand, some preliminary information on the amount of soil C under different land-uses, and provides us with an opportunity to conduct a preliminary assessment of methodologies for periodically updating New Zealand national soil C levels, and their propensity to change. We believe that a system for periodically updating national soil C should consider: use of ‘modal soil pedon’ to increase the efficiency of field sampling to estimate soil C contents of specific combinations of soil-climate-land use; number and classification of key soil groups essential to efficiently and precisely estimate national soil C contents; accuracy of ‘coefficients of change’ estimated from sample points lacking experimental control between land uses; gaps and linkages in estimates of below- and above-ground components of total ecosystem C; number of benchmark, long-term ecological study sites required for a national network representative of key soil-climate-land use categories; and information system requirements of a national soil C monitoring system.
LTEEF-II (Long-term Regional effects of Climate Change on European Forests: Impact assessment and Consequences for Carbon Budget) is EU funded project with 14 participants from 10 countries and it started 1998 and will continue until 2000. The objective of the project is to assess climate change impacts on European forests, in terms of water and carbon fluxes, regional differences, long-term effects, and the overall carbon budget for forests in Europe.
The project consists of two component. The first is impact assessment at the stand level using process-based models. Different models are validated using field data and growth and yield data. Regionally most reliable models are then used to predict the response of forest to climate change scenarios.
The second component is upscaling to the European level using Large Scale Forestry Model (LSFM) and remote sensing. LSFM uses national level forest inventory data and simulates future development of European forests under climate scenarios. The output of LSFM include national harvest levels and carbon balance of forests. In this paper we concentrate on upscailing with LSFM.
Results from Swedish field experiments and ecosystem modeling on the effects of whole-tree harvesting on soil carbon pools are presented and discussed. Soil inventories on 8 field experiments where whole-tree harvesting were made at clear-felling or at thinnings give no support to the hypothesis that whole-tree harvesting leads to reductions in soil carbon pools. Nor is there strong support from field experiments for the hypothesis that whole-tree harvesting reduces the litter production from the next forest generation or ground vegetation. A model of a spruce forest ecosystem predicted that harvesting of logging residues is likely to have a relatively small impact on soil carbon pools. Some research needs were identified.
Antropogenic N deposition causes a range of environmental problems when total N input largely exceed what can be used for tree growth or long-term immobilization in the soil in forest ecosystems. In case there is a soil N build-up, the potential for further immobilization will decrease with time. Thus, if N deposition is constant, leaching losses will increase with time. Increasing N export from the ecosystem through intensified harvesting could be used as a means to improve the N balancing, provided the exported N is transformed into less harmful forms by proper cleaning in the industrial processing.
In average the N budget would overbalance in the southern half of Sweden and underbalance in the northern half of Sweden if whole-tree harvesting is used in all thinnings and at clear-cutting. If stemwood harvesting is used, N deposition exceeds the critical load at over 90 % of the forest area of Sweden. In case an N-budget-adapted harvest intensity would be applied, a balanced N budget could be reached on about 50 % of the forest area.
The soil of forests contains more carbon than the vegetation. For this reason, even small changes in the soil C storage significantly affect the C balance of forests.
The C balance of soil depends on the rates litter production and decomposition. These processes determine respectively C input to soil and output from soil. Forest management actions, such as harvesting, soil preparation, regeneration and fertilization, affect both these processes and may thus either increase or decrease the soil C storage. Similarly, climatic changes affect both litter production and decomposition. The consequent change in the soil C storage depends on how these processes change relative to each other.
The changes in the soil C storage in response to forest management and climatic changes are not reliably known especially due to difficulties in measuring soil C. The changes in the soil C storage during years and decades are expected to be proportionally small, maybe some ten percent. On the other hand, the spatial variation in the amount of soil C is large at any forest site; the amount commonly varies 3-5 fold even within a few meters. It is thus very difficult, if not impossible, to detect the temporal changes in the soil C storage by repeated measurements. In models, soil C is divided for several pools having different dynamic properties. This division thus determines how the models predict the dynamics of soil C. These pools cannot, however, be measured separately. This adds uncertainty in the model predictions. Furthermore, the response to environmental changes is only known for the pools changing most quickly which represent only a few percent of the whole soil C storage. It is common to assume that this response is similar for the rest of the soil C storage too, although this is not necessarily the case.
It seems that our knowledge on the changes in the soil C storage would be most efficiently improved by developing soil C measurements and collecting more data on soil C. However, it seems necessary to develop and commonly accept other means for detecting the changes in the soil C storage than direct measurements before soil can be accounted for like vegetation in the considerations of the C balance of forests.
The carbon reservoir of the trees and surface vegetation of the Finnish forest ecosystem is about 700 Tg C. The carbon reservoir of the wood products in use originated from Finnish forests is estimated to be about 5 % of the carbon reservoir of this total tree biomass. Currently the growth of the managed forests in Finland is greater than the cuttings, causing a carbon sink, a net accumulation of about 14 million tons of CO2 in the forest ecosystem. This considerable carbon sink in the existing forests is not, however, accounted by the Kyoto Protocol, as it limits the consideration to afforestation and reforestation only. The use of bioenergy has been always important in Finland, presently the share of bioenergy of the total primary energy consumption is about 17 %. Increased use of bioenergy and energy conservation are likely to be the main options in controlling the greenhouse gas emissions before 2010. The real development will probably consists of many other factors as well, like a strong increase of the use of natural gas, overall improvement of the efficiency of energy production and to some minor extent of increased use of wind energy.
Combustion of fossil fuels is the main cause for the build-up of the CO2 in the earth’s atmosphere. Additional emissions come from changes in land use, mainly deforestation.
This paper deals with evaluation of bioenergy systems contribution in fulfilling obligations from Kyoto for Croatia. Emissions are calculated for various biomass energy scenarios in Croatia to the year 2030. These results are a part of analysis carried out within BIOEN Program activities and work on recently published document “The Energy Strategy of the Republic of Croatia”.
The given results indicate that bioenergy systems have significant, so far not fully exploited, yet limited possibilities to reduce GHG emissions and help achieving Kyoto targets.
In this 2020 prospective study, a methodology has been developed for analysis of the possibilities of increasing the use of fuelwood, and the socio-economic and environmental implications of the kind of mobilization which would result therefrom. The study deals with five countries within the European Community: Austria, Finland, France, Portugal and Sweden.
The fuelwood share of the energy supply in these five countries could be increased to 9% by the year 2020 if a scenario with an interventionist policy of fuelwood use is assumed in potential user sectors. This could be compared to the present fuelwood share of 5%. There are, however, large differences amongst the five countries. The increased fuelwood use could reduce carbon dioxide emissions by 7% for the year 2020, compared to the present level. The study shows that fuelwood is an economically competitive fuel for energy production in many user sectors. There are, however, a number of non-technical-economic factors (institutional, sociological, political…) which may stand in the way of an increased fuelwood use.
The method of analysing the possibilities for – and consequences of – an increased use of biomass which has been developed in this project could be used for similar analyses of other groups of countries in the European Union.
The aim of this paper is to examine and review the currently used terminology and definitions for woodfuels and other biofuels in the data bank dedicated to the collection and compilation of bioenergy statistical data and present some suggestions for improving this information in the future. For obvious reasons, the paper is mainly focused on the woodfuel statistics compiled by FAO in the current FAOSTAT and reproduced in the Forest Products Yearbook. However, many of the issues of the Unified Wood Energy Terminology (UWET) suggested in this paper for improving the current FAO information system on biofuels would also apply to other data banks of other international and national organizations and agencies involved in similar fields.
The mandate of FAO touches on a number of areas which are of direct relevance to the current international climate discussions such as: the assessment of land-use, land-use changes and forestry sources of green-house gases; the formulation of programmes and policies which can reduce the emissions and assist countries in complying with their commitments under the UNFCCC and the Kyoto Protocol; and the collection and maintenance of relevant datasets, through agricultural statistics and dedicated observation systems such as FRA (Forest Resources Assessment) and GTOS (Global Terrestrial Observation System).
The Organization can play, among others, a useful role in the definition of typologies of agricultural and forestry sources; the formulation of the appropriate agricultural statistical methods that will enable the Conference of Parties to verify the compliance with commitments and the relevance and effectiveness of projects implemented under the “flexibilisation mechanisms”; the standardisation of observation techniques and data exchange; and the formulation of regional and national policies.
Finally, it is suggested that the Inter-Agency Committee on the Climate Agenda, which was specifically set up by several UN agencies to harmonise their climate related programmes, should be resorted to ensure that the inputs by several Agencies, and their relations with countries under the UNFCCC, are properly co-ordinated.
In this presentation, the current situation of the Finnish electricity market have been shortly discussed. The main dynamics are currently the deregulation of the markets and the adaptation to the commintments of the Kyoto protocol. Also, some aspects of Imatran Voima Oy’s (IVO) relation to the bioenergy have been described.
The Canadian Pulp and Paper Association has prepared a report which describes several carbon-sequestering forestry initiatives and gives estimates of their potential impact on Canada’s carbon balance, using available data from empirical studies and current scientific thinking. The report is being presented as a discussion paper initially, to encourage discussion on the concepts and calculations. The C.P.P.A. intends to follow with a position paper, containing refined numerical estimates and also recommendations.
Biomass can play a dual role in greenhouse gas mitigation related to the objectives of the UNFCCC, i.e. as an energy source to substitute for fossil fuels and as a carbon store. However, compared to the maintenance and enhancement of carbon sinks and reservoirs, it appears that the use of bioenergy has so far received less attention as a means of mitigating climate change. Modern bioenergy options offer significant, cost-effective and perpetual opportunities toward meeting emission reduction targets while providing additional ancillary benefits. Moreover, via the sustainable use of the accumulated carbon, bioenergy has the potential for resolving some of the critical issues surrounding long-term maintenance of biotic carbon stocks. Finally, wood products can act as substitutes for more energy-intensive products, can constitute carbon sinks, and can be used as biofuels at the end of their lifetime.