On measurements of formation, growth, hygroscopicity, and volatility of atmospheric ultrafine particles

Atmospheric aerosol particles affect the global climate as well as human health. In this thesis, formation of nanometer sized atmospheric aerosol particles and their subsequent growth was observed to occur all around the world. Typical formation rate of 3 nm particles at varied from 0.01 to 10 cm-3s-1. One order of magnitude higher formation rates were detected in urban environment. Highest formation rates up to 105 cm-3s-1 were detected in coastal areas and in industrial pollution plumes. Subsequent growth rates varied from 0.01 to 20 nm h-1. Smallest growth rates were observed in polar areas and the largest in the polluted urban environment. This was probably due to competition between growth by condensation and loss by coagulation. Observed growth rates were used in the calculation of a proxy condensable vapour concentration and its source rate in vastly different environments from pristine Antarctica to polluted India. Estimated concentrations varied only 2 orders of magnitude, but the source rates for the vapours varied up to 4 orders of magnitude. Highest source rates were in New Delhi and lowest were in the Antarctica. Indirect methods were applied to study the growth of freshly formed particles in the atmosphere. Also a newly developed Water Condensation Particle Counter, TSI 3785, was found to be a potential candidate to detect water solubility and thus indirectly composition of atmospheric ultra-fine particles. Based on indirect methods, the relative roles of sulphuric acid, non-volatile material and coagulation were investigated in rural Melpitz, Germany. Condensation of non-volatile material explained 20-40% and sulphuric acid the most of the remaining growth up to a point, when nucleation mode reached 10 to 20 nm in diameter. Coagulation contributed typically less than 5%. Furthermore, hygroscopicity measurements were applied to detect the contribution of water soluble and insoluble components in Athens. During more polluted days, the water soluble components contributed more to the growth. During less anthropogenic influence, non-soluble compounds explained a larger fraction of the growth. In addition, long range transport to a measurement station in Finland in a relatively polluted air mass was found to affect the hygroscopicity of the particles. This aging could have implications to cloud formation far away from the pollution sources.

Ikääntyminen maalaiskylässä

Aging in a country village This dissertation examines what kind of environment of aging a small country village is, who elderly villagers are and what kind of everyday life they have. The qualitative material gathered through ethnographic field work at a village situated in Southern Finland consists of a field work diary and 34 interviews of elderly villagers. The dissertation is based on social gerontology and village research. The key concepts are: the environment of aging; locality and local identity; and way of life. The village is examined as a social and physical environment of aging. Difficulties regarding mobility are the biggest challenges for elderly villagers in their everyday life. The social environment of aging is constructed by historical, cultural and local factors. The village community is formed by many small sub-communities. An elderly villager s status in a village community and her/his social competence affect the formation of her/his social network and the quality of her/his environment of aging. The dissertation examines the local identities of older villagers and their relationships to the village. The local identities can be based on the village, memories or on many places, or a place and places may not be of great importance for a person s identity. The local identity of an older villager affects her/his experiences of living in the village and her/his future plans to move away from the village. The everyday life of an older villager is constructed by rhythms, routines and repetitions. However, there are differences between how everyday lives are arranged among elderly villagers, which are explained by the concept of a way of life. Four ways of life were found. Nature and its importance are a background to all four ways of life. A traditional way of life is based on continuity and hard work, a family-oriented way of life on family members and relatives. A mobile way of life is characterized by symbolic and concrete mobility. An original way of life is marked by independent loneliness . In practice, a person s way of life is always constructed by two or many ways of life.

Eläytymisestä omiin tarinoihin : Televisiosarja katsojien keskustelussa

From sympathetic understanding to own stories. TV-series in the conversation of its viewers. The purpose of this study is to analyze viewers' conversations about TV-series as a practice in which viewers construct meaning to TV-series. In the tradition of British Cultural Studies this study understands that viewer has an active role in interpreting and constructing meaning to TV-series. In the tradition of feminist studies this study understands that gender is being constructed in social and cultural practices. In reception studies, the viewing of TV-series has usually been analyzed as a practice which is embedded at home and in a family. The studies are often based on interviews of viewers, and the analysis of the construction of meaning is based on interview material where the viewers most often talk about their viewing habits and the likes and dislikes of TV-shows and -characters. This study extends the reception and interpretation of TV-series from home to the moments of interaction between viewers. It is quite common to hear how people talk also outside of home about television and the programmes they have watched. In this study the construction of meaning is being studied in viewers' conversations. The method of analysis is conversation analysis which studies the ordered properties of everyday forms of social interaction. The data has been collected in a workplace where four women watched together (and without the presence of a researcher) two TV-series, American sitcom Golden Girls and Finnish family drama Ruusun aika (Time of a Rose), and afterwards had time and chance for discussion. There was neither a questionnaire nor an agenda for the women to discuss. The analysis of the conversation brings up three themes. In the orientation discussions the viewers aim to construct frames in which it makes sense to talk about the TV-series. The frames have mostly to do with the genre of the TV-series. The second theme is concerned with the viewers' aim to achieve sympathetic understanding of the characters in the TV-series. The third theme extends and transfers the conversation about TV-series to real or imaginary stories of own life. In the conversation the reception of a TV-series appears as being in motion: in the orientation discussions the viewers move towards the series, in the character-discussions the viewers move within the world of the series, and when telling their own stories the viewers move away from the TV-series towards their own lives. In the conversations there appears also a distinction in gender-constructions. When the viewers talk about motherhood, they adopt a serious and moralistic tone. When they talk about female sexuality and relationships between women and men they adopt carnevalistic and humorous tone. There are examples of these kinds of gender-constructions also in other studies of Finnish gender culture. Motherhood means the responsibility to good upbringing; relationships with men include something unpredictable and problematic which one handles at best in a humorous way.

Kansalaisuus ja yhteiskunnallinen yhteisö : T. H. Marshallin ja Talcott Parsonsin perintö nykyaikaiselle kansalaisuustutkimukselle

This work examines the concept of citizenship of TH Marshall and the societal community concept of Talcott Parsons. I am especially interested in whether Marshall s concept of citizenship or Parsons s concept of societal community enable to develop such an analytical framework that creates a basis for relevant examination of how the mechanisms that include or exclude citizenship into the society constitute. The focus is in societal heterogeneity, which will easily introduce multicultural issues in the form of diversity-based conflicts in values, norms and identities. The focus of the review is in the religious orientation and in the examination of the backgrounds of ethnic groups. The research method is the thorough examination of the texts and commenting of the literature of TH Marshall and Talcott Parson, based on which I build my own argumentation and interpretation. As research findings I propose that especially the late works of Talcott Parsons offer analytical tools to study societal pluralism in a way that gives fruitful basis also to the thinking of the 21st century researchers. Parsons s analytical frames of reference form relevant starting points in relation with the social analyses that are made based on inclusion and exclusion. Parsons describes the societal community as differentiated and segmented network, in which different customs and operation models are accepted. Cultural understanding differentiates how and in which context these will be applied. In the conditions of open systems culture can, however, not operate as a connector of the variations of actors neither as a common code that fades away conflicts. Parsons s thinking opens a view into the multicultural world, which is a world society and which consists of ethnic groups that are not internally monolithic but instead in a status of constant cultural redefinition. Individuals and groups are differentiated based on sex, age, different capacities, place of residence, belonging into different collectivities, etc. The late works of Talcott Parsons provide a realistic and an effective, theoretical framework for research of citizenship problems in multicultural conditions. Keywords: citizenship, societal community, society, community, religion, ethnic background, inclusion, exclusion, values and norms.

Huumeriippuvuudesta toipuminen Nimettömien Narkomaanien toveriseurassa

The subjects of this study are Narcotics Anonymous (NA), a non-profit, peer-support-based fellowship, its recovery programme, and the former drug addicts who consider themselves members of the fellowship. The study data consist of episodic interviews (n=24) and questionnaires (n=212). In the collection of questionnaire data, survey research methods had to be applied judiciously. This study analyses NA members background and their substance abuse and treatment history, as well as factors that have contributed to or hindered their bonding with NA. A recovery model is presented that stems from NA s written and oral tradition, and which has been conceptualised into NA s recovery theory. At its simplest, NA s recovery theory can be described in two sentences: 1) There are drug dependent addicts who have an addiction disease. 2) Through an NA way of life, recovery is possible. In this study, addiction and addiction disease are described through recovery stories shared at NA. It also describes how the way of life offered by NA supports recovery from drug addiction, the way of life which recovering addicts have adopted, and how they have done so. The study also presents results that, based on the study data, emerge from participation in the NA programme, and describes how the NA recovery theory works in practice, i.e. how NA members utilise the tools provided by the fellowship and how the lives of recovering addicts change during their membership. Furthermore, this study also discusses criticism of NA. According to the study, NA affects the lives of recovering drug addicts in a number of ways. People of different ages and with a variety of personal, treatment and drug abuse histories seem to benefit from membership of NA. Viewed from the outside, NA may appear as strictly normative, but in practice each member can adapt the programme in a way that suits him/her best. Indeed, flexibility is one of the strengths of NA, but without more extensive knowledge of the fellowship, it is possible that the norms reflected in NA texts or the fanaticism of individual NA members may drive some people away. Due to the increasing number of NA members, the association is also able to provide more alternatives. This study confirms the view that peer support is important, as well as the fact that an official treatment system is required in parallel with peer support activities. NA can never fully replace professional support, neither should it be left with sole responsibility for recovering addicts. Keywords: Narcotics Anonymous, peer support, recovery study, recovery, substance addiction, drug treatment, drugs, explorative research

Kuviteltu aatelismies : Aateluus viholliskuvana ja itseymmärryksenä 1800-luvun Suomessa

An imagined nobleman Nobility as an enemy image and in-group identity in nineteenth-century Finland The focal point of this study is the difficult relationship between two seemingly very different 19th-century elite groups, the upwardly mobile bourgeois intelligentsia and the slowly declining traditional nobility. In the thinking of the bourgeois contender the two emerged as exact opposites, styled as conflicting ideal types: an outdated, exclusive, degenerate hereditary aristocracy versus a dynamic and progressive new force in society, recruited solely on the basis of personal merit, originating from the common people and representing the nation. The appearance of an important 19th-century novelty, print publicity, coincided with the emergence of the bourgeois intelligentsia. The institutions of the developing publishing industry were manned by the aspiring new group. The strengthening flow of progressive, democratic, nationalist ideas distributed via the printing presses carried an undercurrent of self-promotion. It transmitted to the developing readership the self-image of the new cultural bourgeoisie as the defender and benevolent educator of the nation. Having won the contest over the media, the intelligentsia was free to present its predecessor and rival as an enemy of the people. In its politics the nobility emerged as an ideal scapegoat, represented as the source for existing social evils, all if which would promptly go away after its disappearance. It also served as a black backcloth, against which the democratic, national, progressive bourgeois intelligentsia would shine more brightly. In order to shed light on the 19th-century process of (re)modelling the image of nobility as a public enemy I have used four different types of source materials. These include three genres of print publicity, ranging from popular historical and contemporary fiction to nonfictional presentations of national history and the news and political commentaries of the daily papers, complemented by another, originally oral type of publicity, the discussion protocols of the Finnish four-estate parliament. To counterpoint these I also analysed the public self-image of the nobility, particularly vis-à-vis the nationalist and democratic ethos of the modernising politics.

Sterol-binding proteins in late endosomes : Regulation of endosome motility and lipid metabolism

Despite its bad reputation in the mass media, cholesterol is an indispensable constituent of cellular membranes and vertebrate life. It is, however, also potentially lethal as it may accumulate in the arterial intima causing atherosclerosis or elsewhere in the body due to inherited conditions. Studying cholesterol in cells, and research on how the cell biology of cholesterol affects on system level is essential for a better understanding of the disease states associated with cholesterol and for the development of new therapies for these conditions. On its way to the cell, exogenous cholesterol traverses through endosomes, transport vesicles involved in internalizing material to cells, and needs to be transported out of this compartment. This endosomal pool of cholesterol is important for understanding both the common disorders of metabolism and the more rare hereditary disorders of cholesterol metabolism. The study of cholesterol in cells has been hampered by the lack of bright fluorescent sterol analogs that would resemble cholesterol enough to be used in cellular studies. In the first study of my thesis, we present a new sterol analog, Boron-Dipyrromethene (BODIPY)-cholesterol for visualizing sterols in living cells and organism. This fluorescent cholesterol derivative is shown to behave similarly to cholesterol both by atomic scale computer simulations and biochemical experiments. We characterize its localization inside different types of living cells and show that it can be used to study sterol trafficking in living organisms. Two sterol binding proteins associated with the endosomal membrane; the Niemann-Pick type C disease protein 1 (NPC1) and the Oxysterol Binding Protein Related Protein 1 (ORP1) are the subjects of the rest of this study. Sensing cholesterol on endosomes, transporting lipids away from this compartment and the effects these lipids play on cellular metabolism are considered. In the second study we characterize how the NPC1 protein affects lipid metabolism. We show that this cholesterol binding protein affects synthesis of triglycerides and that genetic polymorphisms or a genetic defect in the NPC1 gene affect triglyceride on the whole body level. These effects take place via regulation of carbon fluxes to different lipid classes in cells. In the third part we characterize the effects of another endosomal sterol binding protein, ORP1L on the function and motility of endosomes. Specifically we elucidate how a mutation in the ability of ORP1L to bind sterols affects its behavior in cells, and how a change in ORP1L levels in cells affects the localization, degradative capacity and motility of endosomes. In addition we show that ORP1L manipulations affect cholesterol balance also in macrophages, a cell type important for the development of atherosclerosis.

Tyttöjen toinen koti : Etnografinen tutkimus tyttökulttuurista ratsastustalleilla

Horseback riding is a popular activity in Finland, especially among young women and girls. For centuries, however, horse husbandry and horse culture in Finland had been dominated by men. Nowadays it is mainly the girls who ride as a hobby and take care of the horses. The stable has evolved into an important social sphere for girls, a semi-public room of their own where they spend time together. A study of the girl culture in the riding stable offers a unique perspective as well as new information on becoming a girl and a young woman in Finland. The subject of my research is the girl culture and girls communities at the horseback riding stables. In this thesis I discuss what kind of girl-cultural sphere the stable is, how girls organize their community, and what different aspects and meanings the hobby entails for girls while they are actively engaged in the hobby. I focus on the construction of gender and girlhood and examine how these gender constructions can be theorized as gender tradition. The research material consists of the interviews of 22 stable girls from different parts of Finland and an observation period at one of the stables. The informants were from 13 to 27 years of age. The theoretical background is based on the anthropological study of folklore, girls studies, feminist theory and post-humanist viewpoints. I am interested in how girls culture and girlhood are produced performatively in the interview narration and participant observation. I concentrate on four aspects of this culture: 1) what girls do at the stable, and what kind of relationships they create with horses; 2) social relations focusing on the ways girls construct their own groups, the way their hierarchy is constructed and how they use power; 3) the norms and social control regarding social behaviour; and 4) the reasons girls give for their involvement in the hobby, and girls interest in horses in general. In this girl culture, gender norms and boundaries are not only stretched or transgressed, but the culture also re-produces the hierarchical and stereotypical ideas of gender. The traditions of gender express both the hegemonic gender system and those ideas of gender which girls resist, at least momentarily. Constructions of gender and gender tradition are constituted at the intersections of historical and contemporary expectations of what it means to be a girl. Conscious of these societal demands, girls support, reproduce, challenge, and make comments on them.

Sustainability and Mission Drift in Microfinance

Microfinance institutions (MFIs) are constrained by double bottom-lines: meeting social obligations (the first bottom-line) and obtaining financial self-sufficiency (the second bottom-line). The proponents of the first bottom-line, however, are increasingly concerned that there is a trade-off between these two bottom-lines—i.e., getting hold of financial self-sufficiency may lead MFIs to drift away from their original social mission of serving the very poor, commonly known as mission drift in microfinance which is still a controversial issue. This study aims at addressing the concerns for mission drift in microfinance in a performance analysis framework. Chapter 1 deals with theoretical background, motivation and objectives of the topic. Then the study explores the validity of three major and related present-day concerns. Chapter 2 explores the impact of profitability on outreach-quality in MFIs, commonly known as mission drift, using a unique panel database that contains 4-9 years’ observations from 253 MFIs in 69 countries. Chapter 3 introduces factor analysis, a multivariate tool, in the process of analysing mission drift in microfinance and the exercise in this chapter demonstrates how the statistical tool of factor analysis can be utilised to examine this conjecture. In order to explore why some microfinance institutions (MFIs) perform better than others, Chapter 4 looks at factors which have an impact on several performance indicators of MFIs—profitability or sustainability, repayment status and cost indicators—based on quality-data on 353 institutions in 77 countries. The study also demonstrates whether such mission drift can be avoided while having self-sustainability. In Chapter 5 we examine the impact of capital and financing structure on the performance of microfinance institutions where estimations with instruments have been performed using a panel dataset of 782 MFIs in 92 countries for the period 2000-2007. Finally, Chapter 6 concludes the study by summarising the results from the previous chapters and suggesting some directions for future studies.

Essays on Risk and Return

Perhaps the most fundamental prediction of financial theory is that the expected returns on financial assets are determined by the amount of risk contained in their payoffs. Assets with a riskier payoff pattern should provide higher expected returns than assets that are otherwise similar but provide payoffs that contain less risk. Financial theory also predicts that not all types of risks should be compensated with higher expected returns. It is well-known that the asset-specific risk can be diversified away, whereas the systematic component of risk that affects all assets remains even in large portfolios. Thus, the asset-specific risk that the investor can easily get rid of by diversification should not lead to higher expected returns, and only the shared movement of individual asset returns – the sensitivity of these assets to a set of systematic risk factors – should matter for asset pricing. It is within this framework that this thesis is situated. The first essay proposes a new systematic risk factor, hypothesized to be correlated with changes in investor risk aversion, which manages to explain a large fraction of the return variation in the cross-section of stock returns. The second and third essays investigate the pricing of asset-specific risk, uncorrelated with commonly used risk factors, in the cross-section of stock returns. The three essays mentioned above use stock market data from the U.S. The fourth essay presents a new total return stock market index for the Finnish stock market beginning from the opening of the Helsinki Stock Exchange in 1912 and ending in 1969 when other total return indices become available. Because a total return stock market index for the period prior to 1970 has not been available before, academics and stock market participants have not known the historical return that stock market investors in Finland could have achieved on their investments. The new stock market index presented in essay 4 makes it possible, for the first time, to calculate the historical average return on the Finnish stock market and to conduct further studies that require long time-series of data.

Topics in Spatial Econometrics - With Applications to House Prices

Topics in Spatial Econometrics — With Applications to House Prices Spatial effects in data occur when geographical closeness of observations influences the relation between the observations. When two points on a map are close to each other, the observed values on a variable at those points tend to be similar. The further away the two points are from each other, the less similar the observed values tend to be. Recent technical developments, geographical information systems (GIS) and global positioning systems (GPS) have brought about a renewed interest in spatial matters. For instance, it is possible to observe the exact location of an observation and combine it with other characteristics. Spatial econometrics integrates spatial aspects into econometric models and analysis. The thesis concentrates mainly on methodological issues, but the findings are illustrated by empirical studies on house price data. The thesis consists of an introductory chapter and four essays. The introductory chapter presents an overview of topics and problems in spatial econometrics. It discusses spatial effects, spatial weights matrices, especially k-nearest neighbours weights matrices, and various spatial econometric models, as well as estimation methods and inference. Further, the problem of omitted variables, a few computational and empirical aspects, the bootstrap procedure and the spatial J-test are presented. In addition, a discussion on hedonic house price models is included. In the first essay a comparison is made between spatial econometrics and time series analysis. By restricting the attention to unilateral spatial autoregressive processes, it is shown that a unilateral spatial autoregression, which enjoys similar properties as an autoregression with time series, can be defined. By an empirical study on house price data the second essay shows that it is possible to form coordinate-based, spatially autoregressive variables, which are at least to some extent able to replace the spatial structure in a spatial econometric model. In the third essay a strategy for specifying a k-nearest neighbours weights matrix by applying the spatial J-test is suggested, studied and demonstrated. In the final fourth essay the properties of the asymptotic spatial J-test are further examined. A simulation study shows that the spatial J-test can be used for distinguishing between general spatial models with different k-nearest neighbours weights matrices. A bootstrap spatial J-test is suggested to correct the size of the asymptotic test in small samples.

Transfers of Family Businesses to Non-Family Buyers - The Selling Business Family Perspective

This study focuses on business families and how they handle transitions such as business transfers. It also tries to shift the balance of research away from successions and towards business transfers as a key topic for family business researchers. In addition, it contributes to the family business research field by further highlighting the importance of the various different contributions in the family business from business family members other than the entrepreneurial founder. Based on interviews with both business family members and business brokers, it appears as important for business families who are selling their family business that it is managed in a similar way in the future regardless of the shift in ownership and management. It is also important that the employees can stay with the business. However, employees are seldom regarded as potential buyers of the family business; most preferably, from the point of view of business family members, this should be somebody who is similar to themselves. Business transfers can be lengthy processes, but once the family business is sold, previous owners most often want to leave the family business. This disengagement can be difficult for business family members if they have not managed to build up some other identity outside the family business environment. Money may compensate for the loss in the short run, but something else is needed in the long run, since the management of money is usually not perceived as that interesting. A family business transfer can have great influence on the members of the business family who is selling, and therefore it is suggested that personal due diligence could be of some help when planning the transfer. That tool can help business family members to analyse their own personal situation, but it may also make it easier to understand how the other business family members feel about the forthcoming change. Everyone is influenced in different ways during a family business transfer, and awareness of this fact may make it easier for the whole business family to adjust to their new environment.

Monetary Policy, Stock Price Misalignments and Macroeconomic Instability

Perhaps the most fundamental prediction of financial theory is that the expected returns on financial assets are determined by the amount of risk contained in their payoffs. Assets with a riskier payoff pattern should provide higher expected returns than assets that are otherwise similar but provide payoffs that contain less risk. Financial theory also predicts that not all types of risks should be compensated with higher expected returns. It is well-known that the asset-specific risk can be diversified away, whereas the systematic component of risk that affects all assets remains even in large portfolios. Thus, the asset-specific risk that the investor can easily get rid of by diversification should not lead to higher expected returns, and only the shared movement of individual asset returns – the sensitivity of these assets to a set of systematic risk factors – should matter for asset pricing. It is within this framework that this thesis is situated. The first essay proposes a new systematic risk factor, hypothesized to be correlated with changes in investor risk aversion, which manages to explain a large fraction of the return variation in the cross-section of stock returns. The second and third essays investigate the pricing of asset-specific risk, uncorrelated with commonly used risk factors, in the cross-section of stock returns. The three essays mentioned above use stock market data from the U.S. The fourth essay presents a new total return stock market index for the Finnish stock market beginning from the opening of the Helsinki Stock Exchange in 1912 and ending in 1969 when other total return indices become available. Because a total return stock market index for the period prior to 1970 has not been available before, academics and stock market participants have not known the historical return that stock market investors in Finland could have achieved on their investments. The new stock market index presented in essay 4 makes it possible, for the first time, to calculate the historical average return on the Finnish stock market and to conduct further studies that require long time-series of data.

Re-Conceptualizing Value-Creation From Industrial Business Logic to Service Business Logic

There is an urgent interest in marketing to move away from neo-classical value definitions suggesting that value creation is a process of exchanging goods for money. In the present paper, value creation is conceptualized as an integration of two distinct, yet closely coupled processes. First, actors co-create what this paper calls an underlying basis of value. This is done by interactively re-configuring resources. By relating and combining resources, activity sets, and risks across actor boundaries in novel ways actors create joint productivity gains – a concept very similar to density (Normann, 2001). Second, actors engage in a process of signification and evaluation. Signification implies co-constructing the meaning and worth of joint productivity gains co-created through interactive resource re-configuration, as well as sharing those gains through a pricing mechanism as value to involved actors. The conceptual framework highlights an all-important dynamics associated with ´value creation´ and ´value´ - a dynamics the paper claims has eluded past marketing research. The paper argues that the framework presented here is appropriate for the interactive service perspective, where value and value creation are not objectively given, but depend on the power of involved actors´ socially constructed frames to mobilize resources across actor boundaries in ways that ´enhance system well-being´ (Vargo et al., 2008). The paper contributes to research on Service Logic, Service-Dominant Logic, and Service Science.

Grönlannin mannerjäätikön tulevaisuus: merenpinnan nousu maailmanlaajuisesti ja Itämerellä

Sea level rise is among the most worrying consequences of climate change, and the biggest uncertainty of sea level predictions lies in the future behaviour of the ice sheets of Greenland and Antarctica. In this work, a literature review is made concerning the future of the Greenland ice sheet and the effect of its melting on Baltic Sea level. The relation between sea level and ice sheets is also considered more generally from a theoretical and historical point of view. Lately, surprisingly rapid changes in the amount of ice discharging into the sea have been observed along the coastal areas of the ice sheets, and the mass deficit of Greenland and West Antarctic ice sheets which are considered vulnerable to warming has been increasing from the 1990s. The changes are probably related to atmospheric or oceanic temperature variations which affect the flow speed of ice either via meltwater penetrating to the bottom of the ice sheet or via changes in the flow resistance generated by the floating parts of an ice stream. These phenomena are assumed to increase the mass deficit of the ice sheets in the warming climate; however, there is no comprehensive theory to explain and model them. Thus, it is not yet possible to make reliable predictions of the ice sheet contribution to sea level rise. On the grounds of the historical evidence it appears that sea level can rise rather rapidly, 1 2 metres per century, even during warm climate periods. Sea level rise projections of similar magnitude have been made with so-called semiempirical methods that are based on modelling the link between sea level and global mean temperature. Such a rapid rise would require considerable acceleration of the ice sheet flow. Stronger rise appears rather unlikely, among other things because the mountainous coastline restricts ice discharge from Greenland. The upper limit of sea level rise from Greenland alone has been estimated at half a metre by the end of this century. Due to changes in the Earth s gravity field, the sea level rise caused by melting ice is not spatially uniform. Near the melting ice sheet the sea level rise is considerably smaller than the global average, whereas farther away it is slightly greater than the average. Because of this phenomenon, the effect of the Greenland ice sheet on Baltic Sea level will probably be rather small during this century, 15 cm at most. Melting of the Antarctic ice sheet is clearly more dangerous for the Baltic Sea, but also very uncertain. It is likely that the sea level predictions will become more accurate in the near future as the ice sheet models develop.