The study describes an integrated impact assessment tool for the net carbon dioxide (CO 2 ) exchange in forest production. The components of the net carbon exchange include the uptake of carbon into biomass, the decomposition of litter and humus, emissions from forest management operations and carbon released from the combustion of biomass and degradation of wood-based products. The tool enables the allocation of the total carbon emissions to the timber and energy biomass and to the energy produced on the basis of biomass. In example computations, ecosystem model simulations were utilized as an input to the tool. We present results for traditional timber production (pulpwood and saw logs) and integrated timber and bioenergy production (logging residues, stumps and roots) for Norway spruce, in boreal conditions in Finland, with two climate scenarios over one rotation period. The results showed that the magnitude of management related emissions on net carbon exchange was smaller when compared with the total ecosystem fluxes; decomposition being the largest emission contributor. In addition, the effects of management and climate were higher on the decomposition of new humus compared with old humus. The results also showed that probable increased biomass growth, obtained under the changing climate (CC), could not compensate for decomposition and biomass combustion related carbon loss in southern Finland. In our examples, the emissions allocated for the energy from biomass in southern Finland were 172 and 188 kg CO 2 MW h À1 in the current climate and in a CC, respectively, and 199 and 157 kg CO 2 MW h À1 in northern Finland. This study concludes that the tool is suitable for estimating the net carbon exchange of forest production. The tool also enables the allocation of direct and indirect carbon emissions, related to forest production over its life cycle, in different environmental conditions and for alternative time periods and land uses. Simulations of forest management regimes together with the CC give new insights into ecologically sustainable forest bioenergy and timber production, as well as climate change mitigation options in boreal forests.

In developing countries, securing clean and equal energy access for all is often constrained by lack of understanding of households' energy dependency and influencing factors. This study investigates household-level energy consumption patterns, relevant socioeconomic factors and carbon-emissions from various energy sources. Using a semi-structured questionnaire, we conducted an explorative survey of 189 households in three income groups in a suburban region of Chittagong, Bangladesh. Results suggest that most of the households heavily depend on biomass energy that accounts for 87% of their monthly energy consumption and about two-thirds of energy expenditure. Contrariwise, dependence on non-renewable energy is minimal and accounts for households' 31% monthly energy expenditure. The rich households tend to rely more on electricity, candle, liquid petroleum gas (LPG) while their consumption of the non-renewables is significantly higher than that of medium-income and poor households. Income, education and landholdings of households are positively correlated with expenditure for consuming convenient energy sources such as firewood, electricity and LPG. Firewood, the biomass fuel used most for cooking, is an energy source with the highest carbon emissions-monthly about 192 kilogram carbon dioxide equivalent per household. Our research findings offer insights to enhance household-level clean energy access in Bangladesh and countries alike.

An ecosystem model (Sima) was used to investigate the impact of climate and varying thinning regimes concurrently on energy wood and timber production as well as on growth and carbon stocks during 2010-2099 in southern (below 64°N) and northern (above 64°N) Finland. The analysis was carried out using sample plots from the ninth National Forest Inventory. According to the results, both energy wood and timber production increased under the changing climate, with this effect being found to be higher in northern compared to southern Finland. In relative terms, the effect of forest structure, however, was more pronounced than that of climate, especially in southern Finland. Increased basal area thinning thresholds enhanced carbon stocks compared with current thinning regime. In addition, increased thinning thresholds enhanced concurrently energy wood production (at final felling) and timber production during the period 2040-2069 and merely energy wood production (at final felling) during 2070-2099. In absolute terms, the production potential of energy wood at energy wood thinning was found to be higher in northern compared with southern Finland, but the case was opposite at final felling both in current and changing climate. It was concluded that a concurrent increase in energy wood and timber production as well as carbon stocks would be possible in Finnish forests if thinning was performed at a higher tree stocking level than in the current recommendations.

An ecosystem model (Sima) was utilised to investigate the impact of forest management (by changing both the initial stand density and basal area thinning thresholds from current recommendations) on energy wood production (at energy wood thinning and final felling) and management-related carbon dioxide (CO 2 ) emissions for the energy wood production in Finnish boreal conditions (62°39 0 N, 29°37 0 E). The simultaneous effects of energy wood, timber and C stocks in the forest ecosystem (live and dead biomass) were also assessed. The analyses were carried out at stand level during a rotation period of 80 years for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) growing in different fertility sites. Generally, the results showed that decreased basal area thinning thresholds, compared with current thinning, reduced energy wood (logging residues) and timber production, as well as carbon stocks in the forest ecosystem. Conversely, increased thinning thresholds increased energy wood production (ca. 1-27%) at both energy wood thinning and final felling and reduced CO 2 emissions (ca. 2-6%) related to the production chain (e.g. management operations), depending on the thinning threshold levels, initial stand density, species and site. Increased thinning thresholds also enhanced timber production and carbon stocks in the forest ecosystem. Additionally, increased initial stand density enhanced energy wood production for energy wood thinning for both species, but this reduced energy wood production at final felling for Scots pine and Norway spruce. This study concluded that increases in both initial stand density and thinning thresholds, compared with the current level, could be useful in energy wood, timber and carbon stocks enhancement, as well as reducing management-related CO 2 emissions for energy wood production. Only 2.4-3.3% of input of the produced energy (energy wood) was required during the whole production chain, depending on the management regime, species and sites. However, a comprehensive substitution analysis of wood-based energy, in respect to environmental benefits, would also require the inclusion of CO 2 emissions related to ecosystem processes (e.g. decomposition).

A gap-type ecosystem model was used to assess how climate change may affect the growth (stemwood production), timber production (sawlogs and pulpwood) and carbon stocks in the forest ecosystem (trees and soil) under varying thinning regimes in Finland. Simulations were carried out over a 100-year period under current and changing climate for seven thinning regimes by changing both the basal area threshold when the thinning is performed and the remaining basal area after the thinning. The management recommendations, currently applied in Finnish forestry, were used to define the ''business-as-usual'' treatment. The results indicated that climate change may substantially increase the growth, timber production and carbon stocks in the forest ecosystem. The largest relative changes were found in northern (above 648 N) Finland (south: growth 37Á45%, timber production 23Á40%, carbon stocks 8Á10%; north: 75Á78%, 59Á70%, 21Á23%, respectively, depending on the thinning regimes applied), although the absolute (mean) values were higher in southern (below 648 N) Finland. Regardless of climate scenarios, a reduced level of tree stocking in thinnings may result in cuttings exceeding the growth and result in lower carbon stocks in the forest ecosystem. Conversely, increased tree stocking level up to 30% reduced timber production, but did not remarkably affect the growth and carbon stocks under the current or changing climate. Hence, it may be suggested that if thinning is made at 15Á30% higher stocking than current level it would result in a positive compromise; beyond that, timber production could be reduced drastically.