Browsing by Subject "greenhouse gases"

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  • Verronen, Pekka (Finnish Meteorological Institute, 2017)
    Raportteja - Rapporter - Reports 4:2017
    The 13th International Workshop on Greenhouse Gas Measurements from Space (IWGGMS) will be held on 6-8 June, 2017, at the University of Helsinki in Helsinki, Finland. The workshop is organised by the Finnish Meteorological Institute with support from the University of Helsinki. The workshop gathers together more than 160 scientists from the EU, USA, Japan, China, Australia, Canada, and Russia. This report is the official abstract book of the workshop. Background. Success in space-based global measurement of greenhouse gases, such as carbon dioxide and methane, is critical for advancing the understanding of carbon cycle. The recent developments in observations and in interpreting the data are very promising. Space-based greenhouse gas measurement, however, poses a wide array of challenges, many of which are complex and thus demand close international cooperation. The goal of the workshop is to review the state of the art in remote sensing of CO 2 , CH 4 , and other greenhouse gases from space including the current satellite missions, missions to be launched in the near future, emission hot spots on regional and global scales, process studies and interactions of carbon cycle and climate, pre-flight and on-orbit instrument calibration techniques, retrieval algorithms and uncertainty quantification, validation methods and instrumentation, related ground-based, shipboard, and airborne measurements, and flux inversion from space based measurements. The workshop is part of the programme for the centenary of Finland's independence in 2017. The workshop is also one of the activities arranged by the Finnish Meteorological Institute to support Finland's chairmanship of the Arctic Council, 2017 - 2019. The workshop is sponsored by the Finnish Meteorological Institute, the University of Helsinki, the European Space Agency, the City of Helsinki, the Federation of Finnish Learned Societies, and ABB Inc.
  • Niemistö, Johanna; Myllyviita, Tanja; Judl, Jáchym; Holma, Anne; Sironen, Susanna; Mattila, Tuomas; Antikainen, Riina; Leskinen, Pekka (2019)
    International Journal of Sustainable Development & World Ecology 26 (7): 625-634
    Small and medium-sized enterprises (SMEs) have a substantial role in the economy and job creation, but they are a remarkable source of environmental impacts. SMEs often lack skills and resources to compile environmental impact assessments; Streamlined Life Cycle Analysis (LCA) can provide efficient tools for this. An application of streamlined LCA relying heavily on database data, LCA clinic, was developed and tested on 23 SMEs in Finland. The climate change impacts were mainly caused by the production of raw materials, electricity and heating, whereas packaging and transportation were not influential. A significant amount of emissions were indirect, i.e. caused by production of raw materials. Thus, decreasing emissions from raw material production or selecting raw materials with a smaller environmental load could be a more efficient way to decrease emissions than reducing direct emissions such as those from electricity use. Lack of data in the LCA-databases was considered a challenge. An access to regionally customised datasets is important for the implementation of LCA clinics. Company feedback indicated that LCA clinics were useful in climate-friendly product design and increased environmental awareness, but did not lead to immediate actions to reduce emissions because of inadequate investment capabilities. Company managers had limited possibilities to use the results in marketing as comparative assessments would require a full LCA. Many company managers were willing to pay a fee sufficient to cover the costs of an LCA clinic, but some considered that the costs should be covered by external funding sources.
  • COST action TD1107 (2017)
    Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar's effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar's contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented.
  • Amiri, Ali; Ottelin, Juudit; Sorvari, Jaana; Junnila, Seppo (IOP Publishing, 2020)
    Environmental Research Letters 15 (2020) 094076
    Although buildings produce a third of greenhouse gas emissions, it has been suggested that they might be one of the most cost-effective climate change mitigation solutions. Among building materials, wood not only produces fewer emissions according to life-cycle assessment but can also store carbon. This study aims to estimate the carbon storage potential of new European buildings between 2020 and 2040. While studies on this issue exist, they mainly present rough estimations or are based on a small number of case studies. To ensure a reliable estimation, 50 different case buildings were selected and reviewed. The carbon storage per m2 of each case building was calculated and three types of wooden buildings were identified based on their carbon storage capacity. Finally, four European construction scenarios were generated based on the percentage of buildings constructed from wood and the type of wooden buildings. The annual captured CO2 varied between 1 and 55 Mt, which is equivalent to between 1% and 47% of CO2 emissions from the cement industry in Europe. This study finds that the carbon storage capacity of buildings is not significantly influenced by the type of building, the type of wood or the size of the building but rather by the number and the volume of wooden elements used in the structural and non-structural components of the building. It is recommended that policymakers aiming for carbon-neutral construction focus on the number of wooden elements in buildings rather than more general indicators, such as the amount of wood construction, or even detailed indirect indicators, such as building type, wood type or building size. A practical scenario is proposed for use by European decision-makers, and the role of wood in green building certification is discussed.
  • Danielsson, Rebecca; Lucas, Jane; Dahlberg, Josef; Ramin, Mohammad; Agenas, Sigrid; Bayat, Ali-Reza; Tapio, Ilma; Hammer, Tobin; Roslin, Tomas (2019)
    The use of antibiotics in livestock production may trigger ecosystem disservices, including increased emissions of greenhouse gases. To evaluate this, we conducted two separate animal experiments, administering two widely used antibiotic compounds (benzylpenicillin and tetracycline) to dairy cows over a 4- or 5-day period locally and/or systemically. We then recorded enteric methane production, total gas production from dung decomposing under aerobic versus anaerobic conditions, prokaryotic community composition in rumen and dung, and accompanying changes in nutrient intake, rumen fermentation, and digestibility resulting from antibiotic administration. The focal antibiotics had no detectable effect on gas emissions from enteric fermentation or dung in aerobic conditions, while they decreased total gas production from anaerobic dung. Microbiome-level effects of benzylpenicillin proved markedly different from those previously recorded for tetracycline in dung, and did not differ by the mode of administration (local or systemic). Antibiotic effects on gas production differed substantially between dung maintained under aerobic versus anaerobic conditions and between compounds. These findings demonstrate compound- and context-dependent impacts of antibiotics on methane emissions and underlying processes, and highlight the need for a global synthesis of data on agricultural antibiotic use before understanding their climatic impacts.
  • Koster, Kajar; Koster, Egle; Berninger, Frank; Heinonsalo, Jussi; Pumpanen, Jukka (2018)
    Reindeer (Rangifer tarandus L.) is considered to be an important mammalian herbivore, strongly influencing Arctic lichen-dominated ecosystems. There is no wide knowledge about the effect of reindeer on greenhouse gas (GHG) fluxes in northern boreal forests. Ground vegetation plays an important role in absorbing nitrogen (N) and carbon dioxide (CO2) from the atmosphere. Lately, it has also been found to be a significant source of nitrous oxide (N2O) and a small source of methane (CH4). We investigated the influence of reindeer grazing on field layer GHG (CO2, CH4, and N2O) fluxes, ground vegetation coverage and biomass, and soil physical properties (temperature and moisture) in a northern boreal forest. At our study site, the reindeer-induced replacement of lichen by mosses had contrasting effects on the GHG fluxes originating from the field layer. Field layer CO2 efflux was significantly higher in grazed areas. The field layer was a CH4 sink in all areas, but grazed areas absorbed more CH4 compared to non-grazed areas. Although total N2O fluxes remained around 0 in grazed areas, a small N2O sink occurred in non-grazed areas with lower moss biomass. Our results indicated that grazing by reindeer in northern boreal forests affects GHG fluxes from the forest field layer both positively and negatively, and these emissions largely depend on grazing-induced changes in vegetation composition.
  • Forsius, Martin; Kujala, Heini; Minunno, Francesco; Holmberg, Maria; Leikola, Niko; Mikkonen, Ninni; Autio, Iida; Paunu, Ville-Veikko; Tanhuanpää, Topi; Hurskainen, Pekka; Mäyrä, Janne; Kivinen, Sonja; Keski-Saari, Sarita; Kosenius, Anna-Kaisa; Kuusela, Saija; Virkkala, Raimo; Viinikka, Arto; Vihervaara, Petteri; Akujarvi, Anu; Bäck, Jaana; Karvosenoja, Niko; Kumpula, Timo; Kuzmin, Anton; Mäkelä, Annikki; Moilanen, Atte; Ollikainen, Markku; Pekkonen, Minna; Peltoniemi, Mikko; Poikolainen, Laura; Rankinen, Katri; Rasilo, Terhi; Tuominen, Sakari; Valkama, Jari; Vanhala, Pekka; Heikkinen, Risto K (2021)
    The challenges posed by climate change and biodiversity loss are deeply interconnected. Successful co-managing of these tangled drivers requires innovative methods that can prioritize and target management actions against multiple criteria, while also enabling cost-effective land use planning and impact scenario assessment. This paper synthesises the development and application of an integrated multidisciplinary modelling and evaluation framework for carbon and biodiversity in forest systems. By analysing and spatio-temporally modelling carbon processes and biodiversity elements, we determine an optimal solution for their co-management in the study landscape. We also describe how advanced Earth Observation measurements can be used to enhance mapping and monitoring of biodiversity and ecosystem processes. The scenarios used for the dynamic models were based on official Finnish policy goals for forest management and climate change mitigation. The development and testing of the system were executed in a large region in southern Finland (Kokemäenjoki basin, 27,024 km2) containing highly instrumented LTER (Long-Term Ecosystem Research) stations; these LTER data sources were complemented by fieldwork, remote sensing and national data bases. In the study area, estimated total net emissions were currently 4.2 TgCO2eq a−1, but modelling of forestry measures and anthropogenic emission reductions demonstrated that it would be possible to achieve the stated policy goal of carbon neutrality by low forest harvest intensity. We show how this policy-relevant information can be further utilized for optimal allocation of set-aside forest areas for nature conservation, which would significantly contribute to preserving both biodiversity and carbon values in the region. Biodiversity gain in the area could be increased without a loss of carbon-related benefits.
  • Kuhn, Thomas; Kupiainen, Kaarle; Miinalainen, Tuuli; Kokkola, Harri; Paunu, Ville-Veikko; Laakso, Anton; Tonttila, Juha; Van Dingenen, Rita; Kulovesi, Kati; Karvosenoja, Niko; Lehtonen, Kari E.J. (EGU, 2020)
    Atmospheric Chemistry and Physics 20 9 (2020)
    We use the ECHAM-HAMMOZ aerosol-climate model to assess the effects of black carbon (BC) mitigation measures on Arctic climate. To this end we constructed several mitigation scenarios that implement all currently existing legislation and then implement further reductions of BC in a successively increasing global area, starting from the eight member states of the Arctic Council, expanding to its active observer states, then to all observer states, and finally to the entire globe. These scenarios also account for the reduction of the co-emitted organic carbon (OC) and sulfate (SU). We find that, even though the additional BC emission reductions in the member states of the Arctic Council are small, the resulting reductions in Arctic BC mass burdens can be substantial, especially in the lower troposphere close to the surface. This in turn means that reducing BC emissions only in the Arctic Council member states can reduce BC deposition in the Arctic by about 30 % compared to the current legislation, which is about 60 % of what could be achieved if emissions were reduced globally. Emission reductions further south affect Arctic BC concentrations at higher altitudes and thus only have small additional effects on BC deposition in the Arctic. The direct radiative forcing scales fairly well with the total amount of BC emission reduction, independent of the location of the emission source, with a maximum direct radiative forcing in the Arctic of about −0.4 W m−2 for a global BC emission reduction. On the other hand, the Arctic effective radiative forcing due to the BC emission reductions, which accounts for aerosol–cloud interactions, is small compared to the direct aerosol radiative forcing. This happens because BC- and OC-containing particles can act as cloud condensation nuclei, which affects cloud reflectivity and lifetime and counteracts the direct radiative forcing of BC. Additionally, the effective radiative forcing is accompanied by very large uncertainties that originate from the strong natural variability of meteorology, cloud cover, and surface albedo in the Arctic. We further used the TM5-FASST model to assess the benefits of the aerosol emission reductions for human health. We found that a full implementation in all Arctic Council member and observer states could reduce the annual global number of premature deaths by 329 000 by the year 2030, which amounts to 9 % of the total global premature deaths due to particulate matter.
  • Montagnani, Leonardo; Gruenwald, Thomas; Kowalski, Andrew; Mammarella, Ivan; Merbold, Lutz; Metzger, Stefan; Sedlak, Pavel; Siebicke, Lukas (2018)
    In eddy covariance measureinents, the storage flux represents the variation in time of the dry molar fraction of a given gas in the control volume representative of turbulent flux. Depending on the time scale considered, and on the height above ground of the measurements, it can either be a major component of the overall net ecosystem exchange or nearly negligible. Instrumental configuration and computational procedures must be optimized to measure this change at the time step used for the turbulent flux measurement Three different configurations are suitable within the Integrated Carbon Observation System infrastructure for the storage flux determination: separate sampling, subsequent sampling and mixed sampling. These configurations have their own advantages and disadvantages, and must be carefully selected based on the specific features of the considered station. In this paper, guidelines about number and distribution of vertical and horizontal sampling points are given. Details about suitable instruments, sampling devices, and computational procedures for the quantification of the storage flux of different GHG gases are also provided.
  • Juntheikki, Joni (Helsingfors universitet, 2014)
    Purpose of this thesis is to estimate the carbon sequestration potential in eucalyptus plantations in Uruguay. This study also aims to show how beneficial these plantations are for carbon sinks. The aim of this research is calculate total carbon balance in eucalyptus plantations and compare the results to degraded lands. This study is first-of-its-kind study in Uruguay, but not unique globally. The objective was to use a modeling approach to formulate the results. The methodology of this study is based to the dynamic growth model (CO2fix V3.1). Model is developed to calculate and estimate forest carbon fluxes and stocks. In this study the model was utilized for estimating how much carbon is sequestered in eucalyptus plantations and soils. In this thesis the model was used to simulate eucalyptus forest plantations that stem from numerous studies and different data. Ad hoc Excel model was generated to form calculated results from the simulated data. A separate sensitivity analysis is also formulated to reveal a possible different outcome. The framework is based on a stand-level inventory data of forestry plantations provided by the Ministry of Uruguay (MGAP) and companies. Also multiple scientific reports and previous studies were used as guidelines for simulations and results. The forest stand, yield, soil and weather data used for this study are from three different departments. There are over 700 000 hectares of different species of eucalyptus plantations in Uruguay. The theoretical framework was tested computationally with eleven simulations. CO2fix was parameterized for fast-growing eucalyptus species used in different parts of Uruguay. The model gave outputs per hectare and then this result was scaled up to the national level. This study will also estimate how much grassland (Pampa) and former pasture land could sequester carbon. Situation prior to plantation is a baseline scenario and it is compared to the expected carbon sequestration of plantations. The model is also used to calculate the effect of changing rotation length on carbon stocks of forest ecosystem (forest vegetation and soil) and wood products. The results of this study show that currently the 707,674 hectares of eucalyptus plantations in Uruguay have the potential to sequester 65 million tonnes of carbon and reduce 238 million tonnes of CO2. The calculated carbon storage is 38 and simulated 25 million tonnes of C, products are deducted from the equation. During 22 years (1990–2012) the annual carbon sequestration benefit (afforestation-baseline) without products is 1 757 847 Mg C. The results suggest that it is reasonable to establish eucalyptus plantations on degraded, grassland (Pampa) and abandoned pasture land. The implications of the results are that eucalyptus plantations in Uruguay actually enhance carbon sequestration, are carbon sinks and store more carbon than grassland and abandoned pasture land. Plantations have a vast sequestration potential and are important in mitigating of CO2 emission and effects of the climate change. The findings endorse the significance of plantations to increase carbon sinks and this role will broaden in the future. The most relevant findings of this study are that afforestation increases the soil carbon in 10-year rotation plantations by 34% (101.1>75.6) and in 12-year rotation 38% (104.4>75.6 Mg Cha-1) in a 60-year simulation. The net (afforestation-baseline) average carbon stock benefit in the soil is 25.5 Mg C ha?1 in a 60-year simulation. The (CO2Fix) model indicate that the total average carbon sequestration for eucalyptus plantations is 92.3 Mg Cha?1. The average total carbon storage ranges from 25.8–138.5 Mg Cha?1 during a 60-year simulation. The simulations show that the net annual carbon storage in the living biomass is 29.1, 25.5 (soil) and 37.6 Mg C (products) on the average scenario. There is some fluctuation in the sequestration results in other 10 simulations. Previous studies have showed that the average carbon stock for eucalyptus plantations varies from 30–60 Mg C ha-1, when soil and products are deducted. The capacity of forest ecosystems to sequester carbon in the long run could be even more strengthened if a rotation length increases. Extending rotation from 10 to 12 years increased the average soil carbon stock from 25.5 to 28.8 Mg C (by 13%) in 60 year simulation. The results also indicate that mean annual precipitation (MAP) alters the carbon sinks of the forest ecosystem. There are some limitations in this study and they are clearly explained and analyzed. Hence, most of the results are estimations. Ministry and companies need to prolong planting of trees and even intensify annual programs in order to achieve carbon sequestration targets. Further research is needed to get an estimate of the total forest ecosystem carbon storages and fluxes.
  • Rutanen, Aino (Helsingin yliopisto, 2020)
    Global warming caused by the warming effect of greenhouse gases (GHGs) induces permafrost thaw, which could alter Arctic ecosystems from prominent carbon sinks to potential sources of GHG emissions when polar microorganisms become metabolically more active and have access to carbon compounds that were previously largely unavailable. Polar microbes can have significant contributions to the growing emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and therefore, studies on their metabolism are important. The aim of my study was to investigate polar microbial community composition and diversity as well as functional potential that was related to GHG-cycling in a subarctic environment with genome-resolved metagenomics. Soil cores were collected at the Rásttigáisá fell that is located in Northern Norway. After DNA extraction, ten mineral soil samples were sequenced. Metagenome-assembled genomes (MAGs) were reconstructed using either the combination of human-guided binning and automatic binning or human-guided binning only. Taxonomy was assigned to the MAGs and the functional potential of the MAGs was determined. I recovered dozens of good-quality MAGs. Notably, the MAGs from the mostly unknown phyla Dormibacterota (formerly candidate phylum AD3) and Eremiobacterota (formerly candidate phylum WPS-2) were reconstructed. There were MAGs from the following bacterial phyla as well: Acidobacteriota, Actinobacteriota, Chloroflexota, Gemmatimonadota, Proteobacteria and Verrucomicrobiota. In addition to the bacterial MAGs, MAGs from the group of ammonia-oxidizing archaea were recovered. Most of the MAGs belonged to poorly studied phylogenetic groups and consequently, novel functional potential was discovered in many groups of microorganisms. The following metabolic pathways were observed: CO2 fixation via the Calvin cycle and possibly via a modified version of 3-hydroxypropionate/4-hydroxybutyrate cycle; carbon monoxide oxidation to CO2; CH4 oxidation and subsequent carbon assimilation via serine pathway; urea, ammonia and nitrite oxidation; incomplete denitrification as well as dissimilatory nitrate reduction to ammonium. My study demonstrates how genome-resolved metagenomics provides a valuable overview of the microbial community and its functional potential.
  • Jauhiainen, Jyrki; Kerojoki, Otto; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri (2014)
    Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. Peat temperature dynamics and heterotrophic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes were monitored under four shading conditions, i.e. unshaded, 28%, 51% and 90% shading at experiment sites established on reclaimed fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Groundwater tables on the sites were at about 50 cm depth, the sites were maintained vegetation free and root ingrowth to gas flux monitoring locations was prevented. Half of the four shading areas received NPK-fertilization 50 kg ha−1 for each of N, P and K during the experiment and the other half was unfertilized. Increases in shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference in the topmost 50 cm peat profile was between the unshaded and 90% shaded surface, where the average temperatures at 5 cm depth differed up to 3.7 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO2 emission average on the unfertilized plots and a 66% lower emission average on the fertilized plots. Correlation between peat temperature and CO2 flux suggested an approximately 8% (unfertilized) and 25% (fertilized) emissions change for each 1 °C temperature change at 5 cm depth on the agricultural land. CO2 flux responses to the treatments remained low on degraded peatland. Fertilized conditions negatively correlated with N2O efflux with increases in temperature, suggesting a 12–36% lower efflux for each 1 °C increase in peat temperature (at 5 cm depth) at the sites. Despite the apparently similar landscapes of fallow agricultural land and degraded peatland sites, the differences in greenhouse gas dynamics are expected to be an outcome of the long-term management differences.
  • Karhinen, Santtu; Peltomaa, Juha; Riekkinen, Venla; Saikku, Laura (Elsevier, 2021)
    Global Environmental Change 67 (2021), 102225
    Local governments have set highly ambitious greenhouse gas emission reduction targets on a strategic level, in some cases influenced by intermediary networks. Yet, the quantitative impacts of climate strategies or the sharing of best practices on emissions still remain largely unknown. The aim of this study was to examine the impact of an intermediary network on municipal greenhouse gas emissions. This was done through an econometric analysis of the emissions of municipalities that are members of the Finnish Hinku (Towards Carbon Neutral Municipalities) network, and through comprehensive qualitative interviews conducted in 40 of those municipalities. Our quantitative results show that Hinku network membership has successfully led to the lowering of greenhouse gas emission levels in participating municipalities. The qualitative interviews suggest that this is due to systematic local level climate work, enhanced by network membership. The network functions as an intermediary in two ways: by providing expertise and enabling peer-support. In addition, it has also succeeded in legitimising local level climate action. Ambitious local level climate action can also affect the ambition of national climate policy, which in turn may reflect on the amount resources allocated to local climate action.
  • Mäki-Asiala, Hanna (Helsingin yliopisto, 2021)
    It is necessary actively seek effective ways to reduce agricultural emissions so that the proportion of agricultural greenhouse gas emissions in total national emissions does not increase. The aim of this study was to evaluate with carbon footprint calculators different options for reducing greenhouse gas emissions of dairy production and the carbon footprint of energy-corrected milk. The scenarios included the changes in the dietary concentrate proportion, the proportion of grass in cultivation, the digestibility of roughage and the level of milk production. In addition, the effect of temperature on methane emissions from manure was examined. Data of a dairy farm located in Central Ostrobothnia from year 2020 were utilized in the study. The assessment was carried out by using the carbon footprint calculator developed by the European Commission and the Valio Carbo® environmental calculator. According to the results of both calculators, the effect of the changes in the concentrate proportion in the diet on the carbon footprint of milk was very small. Reducing the proportion of concentrate in the diet reduced total emissions. Reducing the proportion of rapeseed meal in feeding reduced total emissions more than reducing the proportion of barley. Increasing the proportion of grass in cultivation reduced the carbon footprint of milk and the total amount of greenhouse gas emissions with both calculators. According to the European Commission carbon calculator, increasing grass yield and also increasing the proportion of grain in cultivation reduced the carbon footprint of milk and the total amount of greenhouse gas emissions. With Valio Carbo® environmental calculator, increasing the proportion of grain in cultivation increased the carbon footprint of milk and the total emissions. According to European Commission calculator, the total emissions and the carbon footprint of milk decreased when the digestibility of roughage decreased. The increase of milk production level also clearly reduced the carbon footprint of milk with both calculators. However, the change in the milk production level had only a small effect on the amount of emissions produced. Reducing the conversion factor describing the effect of temperature on methane formation from slurry reduced the carbon footprint of milk. The decrease in the conversion factor reduced the emissions from the manure system by 51.3 percentage and reduced the milk carbon footprint from 1.21 to 1.15 kg CO2e/kg ECM. In conclusion, there are many feasible opportunities to reduce the carbon footprint. The most effective ways to reduce total emissions at farm level are to increase the proportion of grass in cultivation and to increase the yield of grass. Raising the milk production level effectively reduces the carbon footprint, but in the future the calculations must take into account that the dry matter intake is higher as the milk yield increases. The main differences between the calculators are currently in the coefficients they use. When comparing the results given by the calculators, it is important to note that the calculation principles cannot fully take into account the possible opposite effects of different factors. The results should be looked critically with a caution that the results given by different calculators are not directly comparable.
  • Soimakallio, Sampo; Kalliokoski, Tuomo; Lehtonen, Aleksi; Salminen, Olli (Springer, 2021)
    Mitigation and Adaption Strategies for Global Change 26: 4
    Forest biomass can be used in two different ways to limit the growth of the atmospheric greenhouse gas (GHG) concentrations: (1) to provide negative emissions through sequestration of carbon into forests and harvested wood products or (2) to avoid GHG emissions through substitution of non-renewable raw materials with wood. We study the trade-offs and synergies between these strategies using three different Finnish national-level forest scenarios between 2015 and 2044 as examples. We demonstrate how GHG emissions change when wood harvest rates are increased. We take into account CO2 and other greenhouse gas flows in the forest, the decay rate of harvested wood products and fossil-based CO2 emissions that can be avoided by substituting alternative materials with wood derived from increased harvests. We considered uncertainties of key parameters by using stochastic simulation. According to our results, an increase in harvest rates in Finland increased the total net GHG flow to the atmosphere virtually certainly or very likely, given the uncertainties and time frame considered. This was because the increased biomass-based CO2 and other greenhouse gas emissions to the atmosphere together with decreased carbon sequestration into the forest were very likely higher than the avoided fossil-based CO2 emissions. The reverse of this conclusion would require that compared to what was studied in this paper, the share of long-living wood products in the product mix would be higher, carbon dioxide from bioenergy production would be captured and stored, and reduction in forest carbon equivalent net sink due to wood harvesting would be minimized.
  • Vilhonen, Enni (Helsingin yliopisto, 2021)
    Improving land management to mitigate climate change is important, especially in agriculture on soils with high organic content. Many studies have found evidence that increasing diversity can help to improve plant biomass production and soil carbon storage. This is attributed to complementarity which consists of more efficient resource use due to niche differences and facilitative interactions. For the total climate impact, the effect of greenhouse gas emissions from the soil needs to be considered. To find out if adding more species to a grass mixture could have similar benefits in boreal zone grass cultivation in Finland, an experiment was set up with four different species mixtures, and three levels of species richness were established under a nurse crop. It was additionally of interest if these effects can counter the emissions of cultivation on organic soils. Biomass samples were collected both before the nurse crop was removed and at the end of the growing season. Both species richness and Shannon diversity index were considered as explanatory factors. Carbon exchange, divided into respiration and photosynthetic capacity, as well as nitrous oxide and methane fluxes, were monitored monthly. There was no strong evidence that species richness affects biomass or greenhouse gas fluxes during the first year. The effect of species richness on the biomass was clearer when the diversity index was considered. These results were significant when the lowest biomass values were excluded from the analysis, probably because complementary resource use needs enough biomass to have an effect. The differences in carbon flux measurements may be sensitive to timing within the growing season since the results closest to significant were obtained at the start of the season. At the time, the measurement conditions were good and the nurse crop biomass was small enough not to obscure the effects of grass mixture. When it comes to other greenhouse gases, species richness had most impact on early nitrous oxide emissions, while methane flux probably needs significantly more time for any changes to appear. Overall, the effect of species richness needs to be studied over the full grass cultivation cycle to find out the full effect. Based on current results, increasing species richness may be an option when other methods cannot be used to reduce emissions and improve carbon sink of agriculture.
  • Huan-Niemi, Ellen; Kaljonen, Minna; Knuuttila, Marja; Niemi, Jyrki; Saarinen, Merja (Scientific Agricultural Society of Finland, 2020)
    Agricultural Food Science 29 4 (2020)
    This study examined what kind of policy instruments and actions are needed for sustainable dietary change and how a large-scale dietary change would impact the climate, thus analysing the economic impacts of transitioning from animal-based diets to alternative plant-based diets. The transition would require the support of horizontal measures that can be implemented throughout the food system. Shifting the emphasis toward the drivers of food demand and consumption will increase the role of new policy instruments and the actors involved in the food system. Collaborative research between environmental and nutritional sciences with economics and policy analysis is necessary to link nutritional health and environmental objectives with economic and social impacts. Less resource-demanding diets would reduce the impact from the food system and lower greenhouse gas (GHG) emissions. Drastic changes in diets and food consumption in Finland would have an impact on primary agricultural production, but the output from the food processing industry would only be slightly affected. However, a successful transition would involve considerable investments in the agricultural and food industry.
  • Myllyviita, Tanja; Soimakallio, Sampo; Judl, Jáchym; Seppälä, Jyri (Springer, 2021)
    Forest Ecosystems 8: 1
    Background: Replacing non-renewable materials and energy with wood offers a potential strategy to mitigate climate change if the net emissions of ecosystem and technosystem are reduced in a considered time period. Displacement factors (DFs) describe an emission reduction for a wood-based product or fuel which is used in place of a non-wood alternative. The aims of this review were to map and assess DFs from scientific literature and to provide findings on how to harmonise practices behind them and to support coherent application. Results: Most of the reviewed DFs were positive, implying decreasing fossil GHG emissions in the technosystem. The vast majority of the reviewed DFs describe avoided fossil emissions either both in processing and use of wood or only in the latter when wood processing emissions were considered separately. Some of the reviewed DFs included emissions avoided in post-use of harvested wood products (HWPs). Changes in forest and product carbon stocks were not included in DFs except in a few single cases. However, in most of the reviewed studies they were considered separately in a consistent way along with DFs. DFs for wood energy, construction and material substitution were widely available, whereas DFs for packaging products, chemicals and textiles were scarce. More than half of DFs were calculated by the authors of the reviewed articles while the rest of them were adopted from other articles. Conclusions: Most of the reviewed DFs describe the avoided fossil GHG emissions. These DFs may provide insights on the wood-based products with a potential to replace emissions intensive alternatives but they do not reveal the actual climate change mitigation effects of wood use. The way DFs should be applied and interpreted depends on what has been included in them. If the aim of DFs is to describe the overall climate effects of wood use, DFs should include all the relevant GHG flows, including changes in forest and HWP carbon stock and post-use of HWPs, however, based on this literature review this is not a common practice. DFs including only fossil emissions should be applied together with a coherent assessment of changes in forest and HWP carbon stocks, as was the case in most of the reviewed studies. To increase robustness and transparency and to decrease misuse, we recommend that system boundaries and other assumptions behind DFs should be clearly documented.