Browsing by master's degree program "Magisterprogrammet i miljöförändringar och global hållbarhet"

Biochar is a porous, carbon-rich material, made from organic material by pyrolysis in low oxygen conditions, and it can be used to sequester carbon into the soil. This review aspires to give an overview of the economic dimensions of using biochar in Finnish (Boreal and sub-boreal) forests. A literature review was conducted to collect and summarize the information about studies and applications elsewhere, and how we could possibly apply them into Finnish forest ecosystems. This thesis is done as part of Helsus Co-Creation Lab -project, where our group was tasked with looking into how biochar could enhance biodiversity in soil and accelerate transformation to low carbon economy. From this larger topic, this paper is looking into the economic side, and whether it is economically viable to use biochar to enhance and uphold biodiversity. This is evaluated by reviewing and categorizing 164 papers and conducting a literature review. My conclusions are that the current biochar applications show lower economic efficiency than other carbon dioxide abatement technologies. The stability of biochar in soil is a key factor, as the half-lives of biochars may not be as long as commonly suggested. Furthermore, competition for biomass resource use can restrict the availability of feedstock, and make it more expensive. Subsidies for biochar application are required if biochar is to be- come a significant part of the national or global climate mitigation policy. The results in different articles are quite variable and there is currently no standard approach to them. There is a need for specific research on what kind of biochar benefits what soil and vegetation, which is expensive. A primary goal is to incorporate a consistent and standardized testing or analysis method for biochar stability into the certification programs run and administered by the International and the European Biochar Initiatives. In the foreseeable future, biochar by itself is unlikely to play a significant role in climate mitigation strategies. Biochar might be just one of several alternatives in a bundle strategy to re- duce carbon emissions. However, its potential use must still be researched more.

Microplastic (MP, <5 mm) contamination of soils has become a critical environmental concern. Plastic mulching films applied in agricultural soils can degrade into MPs, potentially negatively affecting terrestrial ecosystems. Conventional plastics are mainly used in agricultural practices, but the use of biodegradable materials has increased. However, the effects of these polymers on the environment still need to be better understood. The objective of this study was to assess and compare the ecotoxicological effects of mulching film-based microplastics, conventional low-density polyethylene microplastics (PE-MPs) and biodegradable polybutylene adipate terephthalate microplastics (PBAT-BD-MPs), on the earthworm Eisenia andrei. The measured parameters were survival, reproduction, growth, and oxidative stress. In this study, an eight-week reproduction test was conducted using adult earthworms of synchronised age. They were exposed to seven microplastic concentrations: 0%, 0.005%, 0.05%, 0.1%, 0.5%, 1%, 5% (w/w). Oxidative stress was evaluated by analysing six different biomarkers, catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), and lipid peroxidation (LPO). The Integrated Biomarker Response Index (IBR) was provided from biomarker assays, and the soil water-holding capacity and pH were also measured. The results indicated adverse effects on earthworms from both conventional and biodegradable MPs, although impacting different parameters. Responses were observed even at low concentrations; however, no clear dose-response relationship was observed. While exposure to PE-MPs resulted in a decline in earthworm biomass with increasing concentrations, PBAT-BD-MP exposure led to enhanced earthworm growth at lower concentrations. MP exposures did not alter the production of juveniles significantly. However, a minor descending trend in juvenile production was noted with increasing PE-MP concentration, and the juveniles exposed to a 5% concentration of PBAT-BD-MP exhibited lower biomass than the control group. Both MPs caused oxidative stress already at environmentally relevant concentrations. Biomarkers CAT and GR showed significant activation at PE-MP exposure, whereas SOD and LPO levels were impacted at PBAT-MP exposure. This indicates the oxidative damage caused by PBAT-BD-MP exposure. Moreover, both MP types increased soil pH and water-holding capacity at the highest concentration (5%), potentially influencing the observed responses in earthworms subjected to these concentrations. This study provides novel insights into the effects of conventional and biodegradable microplastics on earthworms over various concentrations. Furthermore, it highlights the complexity of microplastics and soil systems, influenced by plastic type, concentration, and environmental conditions.

Peatlands play an important role in the carbon cycle. Natural peatlands are in general sinks of carbon dioxide (CO2) and sources of methane (CH4), whereas drained peatland forests are CH4 sinks but their CO2 emissions increase compared to natural peatlands. Rotational even-aged forestry followed by ditch network maintenance (DNM) affect the water dynamics of the soil by increasing the water table level (WTL) first during clear-cut after which the WTL is lowered by DNM. Rising of WTL causes more anaerobic conditions and risk that CH4 sink turns into CH4 emissions. Lowering the WTL causes more aerobic conditions and strengthens the CH4 sink function but also increases CO2 emissions. In continuous cover forestry (CCF) where only part of the trees are removed, WTL would be naturally maintained. This could maintain CH4 sinks while lowering CO2 emissions by keeping the WTL at an adequate depth. Net emissions of CO2 and CH4 could be expected to follow the changes in CO2 and CH4 concentrations in soil. To understand the processes isotopic values can be used to interpret the production pathways of CO2 and CH4 since different pathways produce different isotope values. In this master’s thesis the aim was to study how the concentration of CO2 and CH4 as well as CO2 isotope values change in a peat soil and how partial harvest affects them. Gas samples were collected from the peat profile (5 – 65cm) at two different drained peatland forests, Lettosuo and Paroninkorpi, from control plots and partial harvested plots during 2019 and 2020. Samples were also collected from the moss layer. In addition, WTL, temperature of peat and O2 concentrations were measured. Concentrations and isotope values were analysed the laboratory with gas chromatography and isotope analyser (Picarro G2201-i). Water table level and temperature were generally higher in partial harvested areas than in control. Highest concentrations of both CO2 and CH4 were found in the deeper layers of the soil. Partial harvest had higher CO2 and CH4 concentrations in the deep layers (50 – 65cm) than control. The differences between partial harvest and control areas could be explained with the higher WTL in partial harvest. The measured isotopic values of CO2 indicated that most of the CO2 in the soil was derived from atmosphere or heterotrophic respiration and only <<20 % of CO2 was derived from CH4 oxidation. Even though both in control and in partial harvest the CH4 concentrations in the deep soil layers were high, the oxidation processes decrease the concentrations under the atmospheric CH4 concentration maintaining the CH4 sinks in both treatments. In partial harvest the CH4 sink is not in risk due to oxidation even though the WTL is higher. This should be verified with gas flux measurements.

Salt-induced flocculation is a process in which dissolved salts in seawater modify dissolved organic matter (DOM) surface charges and enable its transformation into larger fractions. These larger particles can settle to the benthos removing organic matter from the water column. Flocs formed in the flocculation process are often referred to as suspended particulate material (SPM). SPM is an important part of the biogeochemical cycles. SPM is a vector for pollutants, a food source for organisms and a habitat for microbes. Flocculation is part of the estuarine “coastal filter” -system controlling the material fluxes from land to sea. Climate change is causing water temperatures to increase in both inland and coastal waters affecting the biogeochemistry of aquatic ecosystems. Flocculation is a physicochemical process potentially impacted by temperature but the effects of temperature on flocculation are not well known. In my master’s thesis, I studied the effects of water temperature on the salt-induced flocculation of humic-rich river water. The flocculation experiments were conducted in spring 2023 using humic-rich water sampled from Vantaanjoki, Helsinki, Finland. The effects of temperature were studied in two separate experiments at temperatures ranging from 3 ºC to 20 ºC. The studied variables included quantitative suspended particulate matter as well as the optical properties of DOM including colored DOM and fluorescent DOM. Results of the experiments show that temperature did not have a significant effect on the salt-induced flocculation of DOM in humic-rich river water. However, the optical properties of DOM shifted with increasing temperatures and changing flocculation dynamics. Results show that molecular size increased as temperature increased but also when temperature was lower than 3 ºC. Explanation for the observed trends is discussed but more research is needed for more firm conclusions. DOM concentrations are expected to increase in the Arctic and sub-Arctic rivers transporting more organic matter to estuaries. Results of this thesis suggest that rising temperatures will not increase the amount of particulate matter through salt-induced flocculation meaning that a larger portion of the transported material remains in dissolved fraction. Increases in DOM concentrations may shift marine food webs by changing the food and light availability as well as biogeochemistry in estuaries.

Mercury is a toxic heavy metal that ends up in aquatic ecosystems both as atmospheric deposition as well as from the catchment area surrounding the water body. Under the right circumstances, inorganic mercury can be methylated into methylmercury, which accumulates in organisms and food webs and is harmful to humans and animals. Humans are exposed to methylmercury mainly through consumed fish as almost all the total mercury content in fish muscle consist of methylmercury. Mercury content of fish is affected by numerous different factors, such as the food consumed by the fish, the characteristics of the fish species and fish individual, level of lake eutrophication, mercury concentration in water and catchment area. Thesis studies total mercury content and mercury bioaccumulation in cyprinid fish. The species included in the study are roach (Rutilus rutilus), bream (Abramis brama), bleak (Alburnus alburnus), white bream (Blicca bjoerkna), blue bream (Ballerus ballerus), ide (Leuciscus idus), tench (Tinca tinca), rudd (Scardinius erythrophthalmus) and crucian carp (Carassius carassius). Three main research questions were: (1) Can diet of different cyprinid fish explain the mercury content? (2) Is mercury content consistent between fish species in different lake types, or does lake type affect mercury content? (3) Is mercury bioaccumulation consistently similar between fish species between lake types? The fish samples for this study were gathered prior to MSc during July-August in 2020 and 2021 from Kukkia, Hauhonselkä and Pääjärvi, which are classified as mesotrophic lakes, and from eutrophic Vesijärvi, Tuusulanjärvi and Hulausjärvi. Total length, weight, sex, sexual maturity, condition factor (K), fish diet and muscle total mercury content were determined from each fish. The diet of the fish and the differences in the total mercury content were tested with analysis of variance. Mercury bioaccumulation was tested with using linear regression analysis and the slope coefficient obtained from the regression equation was tested for bleak and roach with t-test. From the abundant species of the study the highest length corrected (to length 16.6 cm) mercury contents were measured in bleak and roach, while the contents were lower in white bream and bream. The mercury content differed most clearly in species whose feeding behaviour was very specialized. For example, the differences in mercury contents between bleak, which mainly consumes surface insects and zooplankton, and bream, which prefers benthic food, were clear in every lake studied. Mercury contents were mainly higher in mesotrophic lakes compared to eutrophic lakes, but results varied by species. In addition to fish diet and lake type, fish’s metabolism, growth rate and life cycle length probably influenced the species-specific mercury contents. When comparing the abundant species, the bioaccumulation of mercury was steepest in bleak and roach. Compared to these species’ bioaccumulation was slower in white bream and bream. When comparing mercury bioaccumulation within species between different lake types, the differences were species-specific. For example, the bioaccumulation of bleak was consistently steeper in mesotrophic lakes compared to eutrophic lakes, but the bioaccumulation of white bream was steeper in eutrophic lakes. Based on this study, it can be concluded that mercury content and bioaccumulation in cyprinid fish were influenced by e.g., species-specific characteristics, fish diet and level of the lake productivity. In addition to these factors, mercury content and bioaccumulation of fish may have been affected by the land use of the lake catchment area, as well as the anoxic areas of the lakes, which are propitious places for methylation. This study provided valid information on which factors may be relevant for cyprinid fish when observing their mercury content and bioaccumulation.

Abstract As part of the Kunming-Montreal Global Biodiversity Framework business are expected to make commitments for halting and reversing the loss of biodiversity. The political drivers are forcing ministries, regions, and cities but also companies to create their own strategies and actions to conserve biodiversity. Despite the considerable attention given to climate policies within businesses, there exists a lack of attention to the roles and responsibilities of businesses in conserving biodiversity. While concerns are escalating, many businesses seem less aware of the scale of their influence and the necessary actions needed to conserve biodiversity. Also, their understanding of the significance of actions concerning biodiversity loss remains relatively low. This study addresses the critical need for increased business involvement in multi-level and cross-sectoral biodiversity governance while emphasizing the leadership necessary to facilitate this endeavor. I aim to bridge this gap by identifying barriers and opportunities for enhancing business engagement in preserving biodiversity and investigating the emerging new leadership needs. This study examined the Business@Biodiversity network, which is the leading business network for biodiversity in Sweden. Semi-structured interviews were conducted with key stakeholders across various industries (n=12). These interviews assessed member companies’ awareness, commitment, and strategies toward biodiversity conservation. Through this context, the study seeks to clarify the underlying issues that hinder effective business involvement in biodiversity conservation, while capturing the opportunities for biodiversity-focused leadership. Results show that Swedish businesses face barriers such as regulatory complexities, and the absence of standardized measurements in engaging with biodiversity. However, they also recognize opportunities within a shifting labor market, underscoring the need for balanced regulations and collaborative platforms to enhance conservation efforts. Finally, this study suggests actionable areas for enhancing business involvement in biodiversity conservation, including prioritizing imperfect action over inaction, establishing a common language and baseline, leveraging political and economic instruments, and mainstreaming biodiversity. This research contributes to advancing the discourse on business engagement in biodiversity conservation, offering insights and recommendations to inform policy and practice, driving meaningful action toward preserving biodiversity.

Electronic waste is the fastest growing type of waste stream in the world, and this development results from the rapidly accelerating digitalization. Electronic devices become obsolete on an accelerating speed, as there are constantly more powerful devices coming to the market. The most significant environmental impacts of this development are greenhouse gas emissions and natural resource consumption. Circular economy has been proposed as a solution to these environmental challenges, and the goal of this approach is to preserve the value of the materials in the circulation as efficiently as possible. One way of implementing the principles of circular economy is the product-as-a-service-based business model. This research examines the differences between the product-as-a-service-based model and ownership-based model in terms of the environmental impacts that are related to the laptop and tablet procurements. The results of this thesis will be utilized in implementing the actions of the City of Helsinki’s Roadmap for Circular and Sharing Economy. This research was conducted as streamlined life cycle assessment, in which the systematic literature review was used for tracking the environmental impacts of the products’ life cycle stages and components. In addition, expert interviews were carried out in order to collect information about the reuse and recycling practices of the supplier companies that follow these previously mentioned business models. Finally, based on the results of the systematic literature review and the interviews, the company specific differences were assessed in terms of the greenhouse gas emissions and material waste that result from the procurements. The City of Helsinki’s annual procurement volumes were used in this assessment. Based on the results of this research, production and use are the most significant life cycle stages in terms of the devices’ greenhouse gas emissions. Printed circuit boards/printed wiring boards, integrated circuits, displays, and casings are the components with the most significant impact. The results suggest that increasing the lifespan of the devices provides opportunities for significantly lowering impacts in both impact categories, if the devices are efficiently recycled after this.

Lichens are sensitive organisms widely used for environmental biomonitoring. Urban environments have been under heavy pollution, especially sulphur dioxide and nitrogen oxides, due to human activity which has led to the disappearance of lichens in city centres. Regulations and technological changes have led to cleaner air and less deposition of pollutants, especially sulphur dioxide on the vegetation in both rural and urban areas. This in turn has led to recolonization of lichens in former lichen deserted areas. In this study epiphytic macrolichens on park maples were surveyed using simple tree-based random sampling in three parks in Helsinki, and in one park in Loviisa, Siuntio and Raasepori each. The sampling and surveying methods were selected based on the SFS standard “Ambient air. Biomonitoring with lichens. Assessing epiphytic lichen diversity”. Species identification took place on site and in Botanical museum (Finnish Museum of Natural History). The results from parks in Helsinki were used to estimate if lichens have recolonized the trees. In addition, the results from the other Uusimaa municipalities were used to assess how different is the lichen species assemblage when comparing the relatively more polluted region of Helsinki to the less polluted regions in Uusimaa. The study found that pollution levels in Helsinki have declined enough to enable recolonization, of which there have been signs already in 1990s and 2000. The study used lichen diversity value of defined functional groups as one of the statistical methods which gave new information about how the species tolerance or sensitivity to pollutants shapes the recolonization. Comparison between the study areas in Uusimaa region revealed that concentrations of nitrogen oxides steer lichen species assemblage in Helsinki. Lichen surveys in Helsinki are scarce. This study brings topical information about the lichen situation in Helsinki, and it uses an as yet relatively unknown method to extract information from lichen assemblage. Regular, comparable lichen surveys are needed to further research the pressure that human activities cause on urban nature. Such time series would help to monitor both the urban nature loss and the impact of climate change on the urban nature.

It is widely acknowledged that previous efforts to communicate the severity and rate of climate change have failed. Science communication has for decades relied on the presumption that more information leads to more informed decisions, thus so far, the scientific consensus about human-caused climate change has not resulted in required changes in behaviour. Previous communication efforts have, for the most part, attributed inaction to the lack of information, but in doing so, have excluded many social and psychological elements of communication. Although raising the level of awareness about climate change has been successful, climate change remains to be perceived to be a distal threat. Recently, more sophisticated approaches have been developed to meaningfully communicate climate change, drawing attention to the framing of the communication. In this study, a new approach to science-based environmental communication is evaluated. The case study seeks to address how immersive Virtual Reality (VR) can be used as a tool in science-based environmental communication for policymakers in a locally relevant context. Via immersive VR, information about forests’ role in climate change is mediated to forest policymakers. In the science communication, climate change is framed as an experiential, local, and present risk, promoting a problem definition that focuses on the climate effects of forest utilisation. I evaluate the success of the science-based environmental communication by measuring participants’ personal responses. I focus on measuring enjoyment, interest, trust, and usability. The study participants are members of the Parliament of Finland and governmental officials from the Ministry of Agriculture and Forestry; and the Ministry of the Environment. The study material consists of feedback forms from participants (N=65) and interviews of the key actors (N=7). To consider the historical background and many conflicting interests in Finnish forest and climate politics, I focus on the comparison between the natural resource position and the environmental position. The results of this study offer compelling evidence for how differently policymakers representing these two positions perceive the usage of immersive VR in science-based environmental communication. The environmental position indicated significantly higher levels of success on all measured components. Considering that the science communication framed forest utilisation as an environmental issue, it is not surprising that participants holding the environmental position perceived the science communication to be more enjoyable, interesting, trustworthy, and usable. Accordingly, the study results provide additional support for the idea of Finnish forest policy as a polarised field of policy with two main positions. With the means of immersive VR, I was able to induce strong personal responses to the science communication. Participants holding the natural resource position were more likely to challenge the legitimacy of the information and the use of VR in science communication than participants holding the environmental position. The results point to the likelihood that communicating climate change via immersive VR can induce strong negative emotions in the participants, but when the communication is comparable with the policymaker's policy preferences, they respond more positively. The study results also suggest, that to communicate climate change more meaningfully, immersive VR should be further explored as a supplementary tool in science communication.

In recent years, the science community has increasingly emphasized the influence of behavior, lifestyles, and culture on greenhouse gas emissions. Finland’s emissions per capita (~10 tCO2/yr.) are amongst the highest in the world, and it has been calculated that to comply with the Paris Agreement and to limit global warming to well below 2 °C, Finnish households should reduce their carbon footprint by 70 % by 2030. This requires drastic lifestyle changes, especially regarding mobility, housing, and nutrition. However, knowing this is not enough to change behaviors. Human behavior is influenced by several different internal and external factors such as knowledge, values, and social structures. This master’s thesis is a case study conducted in the Environmental Change and Global Sustainability (ECGS) master’s program at the University of Helsinki with the aim to enrich theories about pro-environmental behavior by providing insights on the future aspirations of sustainability science students, who have both extensive knowledge and experience in the field of sustainability. The data for this study was collected through an anonymous, online questionnaire with four open-ended questions. In total, 61 out of 274 ECGS students answered the questionnaire, after which qualitative content analysis with both inductive and deductive elements was applied to analyze the results. The results confirm that ECGS students are indeed well aware of the most impactful lifestyle changes for reducing personal carbon footprint. Despite their extensive knowledge on sustainability, the students’ future aspirations still come quite close to the dominant cultural vision of a good life in Finland. The implications of these findings once again confirm the importance of facilitating sustainable ways of living through changes in societal structures, discourses, and norms.