Browsing by Subject "carbon sink"

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  • Kinnunen, Antti; Talvitie, Ilmari; Ottelin, Juudit; Heinonen, Jukka; Junnila, Seppo (Elsevier, 2022)
    Sustainable Cities and Society
    Cities are hotspots of anthropogenic activity and consumption. Thus, the consumption-based carbon footprints of their residents are pronounced. However, the beneficial climate impacts attributable to individual residents, such as carbon sequestration and storage (CSS) provided by residential green spaces and housing, have received less attention in the scientific literature. This review article presents an overview of the current research on the urban residential environment's CSS potential and argues for its inclusion in the so-called carbon handprint potential of individual consumers. The focus of existing research is on developed countries, and in empirical studies the absence of compiling literature presents a clear research gap. Most current potential is estimated to lie within the carbon pools of residential vegetation, soils and wooden construction, with biochar and other biogenic construction materials presenting key future development pathways. The underlying background variables guiding the formation of a residential carbon pool were identified as extremely complex and interconnected, broadly classified into spatial, temporal and socioeconomic factor categories. Our findings suggest that there is significant potential for growth in the residential CSS capacity, but substantial efforts from the scientific community, urban planners and policy-makers, and individual residents themselves are needed to realise this. Highlights • Residential vegetation, soil and housing can store substantial amounts of carbon. • Biochar and biogenic construction materials offer novel opportunities in the field. • Underlying background variables are extremely complex and related to urban form. • Residential carbon sink potential can be utilised to mitigate related emissions. • More research is needed, especially in the developing countries.
  • Lehtonen, Ilmari (Helsingin yliopisto, 2020)
    In this paper, I examine the discussions around the concept of carbon sinks. From those discussion of Finnish forestry, I identify frames based on a media material of 108 news articles combining the methodologies of frame analysis and content analysis. I aim to contextualize the carbon sink discussions of the latter half of 2010s and examine how the natural science-based term is used to support varying policy agendas. Building from background literature on the media as a societal actor and a context around Finnish forest discussions and mismatches between science and forest policy, I reflect on the ways that Finnish media frames and contextualizes carbon sink-related forest discussions. Eventually, I identify three dominant and eight secondary frames that describe the ways of using and the transforming of carbon sink as a term in detail. The dominant frames divide the discussion into two clashing ways to communicate carbon sink issues and a third middle ground way of understanding and using the term. The middle ground frame identifies the conflict between the clashing frames and suggests reaching to an understanding as a priority goal in terms of optimal climate change policy. I discuss the results in terms of the frames' policy implications. In addition, I ask how they signal potential developments in forest and climate policy and discourse. The analysis shows that the clearest disagreements in the carbon sink conflicts raise from how forestry restricting policies are seen to affect carbon sink levels and how prominent a role should forest industry have in meeting national and international climate policy targets. The study confirms that carbon sink as a term transforms into altering forms to support distinct, even controversial policy goals because of both definitional and calculative uncertainties.
  • Holmberg, Maria; Aalto, Tuula; Akujarvi, Anu; Arslan, Ali Nadir; Bergstrom, Irina; Bottcher, Kristin; Lahtinen, Ismo; Makela, Annikki; Markkanen, Tiina; Minunno, Francesco; Peltoniemi, Mikko; Rankinen, Katri; Vihervaara, Petteri; Forsius, Martin (2019)
    Forests regulate climate, as carbon, water and nutrient fluxes are modified by physiological processes of vegetation and soil. Forests also provide renewable raw material, food, and recreational possibilities. Rapid climate warming projected for the boreal zone may change the provision of these ecosystem services. We demonstrate model based estimates of present and future ecosystem services related to carbon cycling of boreal forests. The services were derived from biophysical variables calculated by two dynamic models. Future changes in the biophysical variables were driven by climate change scenarios obtained as results of a sample of global climate models downscaled for Finland, assuming three future pathways of radiative forcing. We introduce continuous monitoring on phenology to be used in model parametrization through a webcam network with automated image processing features. In our analysis, climate change impacts on key boreal forest ecosystem services are both beneficial and detrimental. Our results indicate an increase in annual forest growth of about 60% and an increase in annual carbon sink of roughly 40% from the reference period (1981-2010) to the end of the century. The vegetation active period was projected to start about 3 weeks earlier and end ten days later by the end of the century compared to currently. We found a risk for increasing drought, and a decrease in the number of soil frost days. Our results show a considerable uncertainty in future provision of boreal forest ecosystem services.
  • Korhonen, Samuli Joonatan (Helsingin yliopisto, 2020)
    We analyse the forest reference level (FRL) projection in Finland. FRLs are included in the European Unions’ new land use, land-use change and forestry (LULUCF) regulation (EU 2018/841) that is part of the actions towards the Paris Agreement’s climate mitigation targets. The regulation defines the accounting rules for carbon dioxide (CO2) emissions within the sector. We build on the LULUCF regulation, the provided guidance documents on the FRL projection, national forestry accounting plans and the existing studies concerning the FRL projections. Business-as-usual reference levels were used for the Kyoto Protocol’s second commitment period. The parties of the Kyoto Protocol had an incentive to report high harvest levels (Frieden et al. 2012). Thus, the reference levels overestimated the harvests by including in assumptions about future policies. Some of the assumptions did not materialize and this led to windfall carbon credits (Grassi et al. 2018, Krug 2018). Such overestimation has happened, for example, in Finland. In this thesis we analyse, whether the new forest reference levels are able to avoid problems that occurred during the Kyoto Protocol. The LULUCF regulation is set for the compliance period (CP) of 2021-2030. The forest reference level is a baseline projection for the forest carbon sink, defined by the historical forest management practices of the reference period (2000-2009). Age-related dynamics of the forest can be taken into account but any anticipated policy changes need to be excluded from the projection. The FRL indirectly defines the level of harvests that are not considered as emissions. The excess carbon sink can be traded to other Member States or be used to compensate the effort sharing sector’s emissions. One of the suggested principles to project historical forest management is to utilize the intensity of management (Grassi and Pilli 2017, Grassi et al. 2018), which is calculated by dividing the reference period’s harvest by the amount of biomass that was available for the wood supply during the same period. The future harvest level is computed by keeping the intensity of management constant. This principle is used in Finland and in several other EU member states. To analyse the suggested principle, we utilize a partial equilibrium model for forestry and agriculture (Mitra and Wan 1985, 1986, Salo and Tahvonen 2004). Using this model, we are able to compute a FRL in a case where policy shock has increased harvest levels after the reference period. This resembles the situation in Finland. Our numerical results show that the choices on the biomass available for wood supply, interest rate and the starting year of the projection can have significant impacts on the FRL computation. By these choices, a member state is able to overestimate the harvest possibilities. Thus, the EU fails to set a regulation that fully excludes national incentives in specifying the FRL. The setting of the Finnish FRL includes a tendency of minimizing the restrictions on the future harvest levels. This outcome follows by choosing high interest rate, early starting year for the projection and a loose definition for the biomass available for wood supply.
  • Saarni, Matti (Helsingin yliopisto, 2019)
    Climate change affects the human habitat and the mechanics that cause this scientific phenomenon are somewhat well known. This study examines how forest policy, agricultural policy and environmental policy can control the mechanisms that cause climate change. The material of the study consists of interviews of 12-13 Finnish experts, each representing one of the previously mentioned sectors. Each of the experts have been asked 13-14 questions about the importance of climate change mitigation, as well as the mechanisms by which agriculture and forests affect the climate and how climate change should be considered in environmental policy. The data was collected between October 8th and November 8th of 2019. This was in five weeks after the IPCC 1,5-degree climate report was published. A series of topics was constructed from the answers, and they are meant to be used as topics to be discussed in the Finnish 2019 parliamentary election. In addition, on how important scientific academics see the control of climate change, they were also asked how critical climate change is. The interview material is stored in the Finnish Social Science Data Archive ( The experts’ answers to the importance of controlling climate change were almost unanimous and considered to be highly important. Carbon sink and storage were considered the most effective methods to control climate change. According to the results, the study proposes topics that should be discussed in politics and when a person wants to advance the control of climate change in forest, agriculture and environment politics. Political decisions are often based on value judgement, which again are based on the information of different methods efficacy. The results that are discussed in this study are not the only options, but they give guidelines and reasons for discussions related to effective choices. Forest policies should recognize the effects of forest industry to the development of carbon sink and storage. Forest industries prerequisite for operation and decision making in addition to considering employment and export industry, must also consider the effect for Finland’s net carbon emissions. Activities which lengthen the forest rotation time would have multiple positive benefits and increase forest carbon storage. Agricultural politics should broaden the discussion to reach food politics. Consumption habits have big effect on agricultural production structure and it can be directed by many ways. The structure of agricultural production should also be considered from the emission point of view, because the land use is substantially large and changes in production can affect Finland’s emission in a scale, that would have large effect on our nations net carbon emissions. To strengthen carbon sinks, landowners should have compensation mechanism methods, that increase carbon sinks, and which are combined to the size of the carbon storage. In environmental policy climate change must be paid more attention and governmental boundaries must not intervene significant decision making. The strengthening of the role of Ministry of the Environment and adding co-operation between different ministries supports the decision making regarding environmentally positive issues.
  • Holder, Jonathan (Helsingin yliopisto, 2019)
    Forests have acted as a substantial Carbon sink during the last decades. In Finland, forests currently sequester about half of the total anthropogenic CO2 emissions. In order to mitigate climate change, most recent policies, both on the European and the Finnish level, are focussing on increasing forest utilisation, and use forest biomass to substitute fossil resources for material or energy production purposes. However, as increasing harvests commonly reduce the growth potential of forests, their function as a carbon sink could be reduced. This reduction of the forest carbon sink might offset the reduction in emissions gained by substitution. The aim of this study is to analyse how different levels of forest utilisation, i.e. harvest levels, and climate change affect the carbon sink function of Finnish forests at a national level during the period of 2015–2100. In order to quantify these effects in detail, the semi-empirical, climate- and management-sensitive forest growth simulator FORMIT-M is employed to estimate carbon stocks and fluxes in living biomass. The carbon stocks and balances of soils are calculated by applying the Yasso15 soil model to litter input as modelled by FORMIT-M. The carbon balance of harvested wood products is estimated by applying species- and assortment-specific decay functions to harvested timber assortments derived from dimensions. Four harvest scenarios were applied, covering total annual harvest levels between 40 and 87 million m3 a-1, i.e. both reduced and increased levels compared to current levels. The simulations were run for three climate scenarios: current climate (1981-2010 means), and RCP2.6 and RCP8.5 scenarios, the latter two based on predictions of the general circulation model CanESM2. The general findings of the simulations largely confirm earlier research, indicating that higher harvest levels decrease the total C sink. This was true across all climate scenarios examined; in general, the total C sink function of forests was predicted to increase under climate change conditions, with higher C sinks under RCP8.5 than RCP2.6. Under climate change, the relative effect of increasing harvests is reduced, but management in the form of harvest levels remains a more influential factor than climate change. In addition, the reduction in C sink function per unit of additionally harvested C is larger at higher harvest levels, especially under current climate. In the highest harvest scenario, managed forests acted as C sources in the beginning of the modelling period, and the total Finnish forest areas remain net C sinks only due to net C sequestration in preservation areas during this period. The simulations of this study therefore suggest that, from a climate change mitigation perspective, a reduction of harvests is more beneficial than increasing harvests. This is true even when avoided greenhouse gas emissions by replacing fossil resources with forest biomass are considered in the form of a rough estimation of substitution effects. In general, both the absolute magnitude of the C sink and the differences between harvest scenarios are likely to be overestimated in this study, as neither the reduction in growth potential nor the potential reduction of C stocks due to natural disturbances were considered; in addition, potential limiting factors such as nutrient deficiency did not restrict the fertilisation effect of elevated atmospheric CO2 levels. The results include large uncertainties, both regarding the effect and extend of climate change and the potential accumulation of misrepresentations within the growth modelling; hence, the reliability can be expected to decrease during the modelling period. Future applications of the FORMIT-M simulator in Finland should consider the effects of natural disturbances as well as limitations to the substantially improving growing conditions due to climatic conditions and elevated atmospheric CO2 levels; in addition, an optimisation procedure for the distribution of harvests would be beneficial.
  • Haeni, M.; Zweifel, R.; Eugster, W.; Gessler, A.; Zielis, S.; Bernhofer, C.; Carrara, A.; Gruenwald, T.; Havrankova, K.; Heinesch, B.; Herbst, M.; Ibrom, A.; Knohl, A.; Lagergren, F.; Law, B. E.; Marek, M.; Matteucci, G.; McCaughey, J. H.; Minerbi, S.; Montagnani, L.; Moors, E.; Olejnik, J.; Pavelka, M.; Pilegaard, K.; Pita, G.; Rodrigues, A.; Sanz Sanchez, M. J.; Schelhaas, M. -J.; Urbaniak, M.; Valentini, R.; Varlagin, A.; Vesala, T.; Vincke, C.; Wu, J.; Buchmann, N. (2017)
    Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g., climate and nutrients) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY)defined as the day of year when winter net carbon losses are compensated by spring assimilationfor NEPc in 26 forests in Europe, North America, and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needleleaf forests (R-2=0.58) and deciduous broadleaf forests (R-2=0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of cDOY depended on the integration method for NEPc, forest type, and whether the site had a distinct winter net respiratory carbon loss or not. The integration methods starting in autumn led to better predictions of NEPc from cDOY then the classical calendar method starting 1 January. Limited explanatory power of cDOY for NEPc was found for warmer sites with no distinct winter respiratory loss period. Our findings highlight the importance of the influence of winter processes and the delayed responses of previous seasons' climatic conditions on current year's NEPc. Such carry-over effects may contain information from climatic conditions, carbon storage levels, and hydraulic traits of several years back in time.