ALBERT

Description:    Vertical diffusivity and oxygen consumption in the basin water, the water below the sill level at about 59 m depth, have been estimated by applying budget methods to monitoring data from hydrographical stations BY4 and BY5 for periods without water renewal. From the vertical diffusivity, the mean rate of work against the buoyancy forces below 65 m depth is estimated to about 0.10 mW m −2 . This is slightly higher than published values for East Gotland Sea. The horizontally averaged vertical diffusivity κ can be approximated by the expression κ =  a 0 N −1 where N is the buoyancy frequency and a 0  ≈ 1.25 × 10 −7  m 2  s −2 , which is similar to values for a 0 used for depths below the halocline in Baltic proper circulation models for long-term simulations. The contemporary mean rate of oxygen consumption in the basin water is about 75 g O 2  m −2  year −1 , which corresponds to an oxidation of 28 g C m −2  year −1 . The oxygen consumption in the Bornholm Basin doubled from the 1970s to the 2000s, which qualitatively explains the observed increasing frequency and vertical extent of anoxia and hypoxia in the basin water in records from the end of the 1950s to present time. A horizontally averaged vertical advection–diffusion model of the basin water is used to calculate the effects on stratification and oxygen concentration by a forced pump-driven vertical convection. It is shown that the residence time of the basin water may be reduced by pumping down and mixing the so-called winter water into the deepwater. With the present rate of oxygen consumption, a pumped flux of about 25 km 3  year −1 would be sufficient to keep the oxygen concentration in the deepwater above 2 mL O 2  L −1 . Content Type Journal Article Category Report Pages 1-9 DOI 10.1007/s13280-012-0356-4 Authors Anders Stigebrandt, Department of Earth Sciences/Oceanography, University of Gothenburg, Box 460, 40530 Gothenburg, Sweden Ola Kalén, Department of Earth Sciences/Oceanography, University of Gothenburg, Box 460, 40530 Gothenburg, Sweden Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description:    We relate the historical (1850–2000) spatial and temporal changes in cropland cover in the conterminous United States to several socio-economic and biophysical determinants using an eco-region based spatial framework. Results show population density as a major determinant during the nineteenth century, and biophysical suitability as the major determinant during the twentieth century. We further examine the role of technological innovations, socio-economic and socio-ecological feedbacks that have either sustained or altered the cropland trajectories in different eco-regions. The cropland trajectories for each of the 84 level-III eco-regions were analyzed using a nonlinear bi-analytical model. In the Eastern United States, low biophysically suitable eco-regions, e.g., New England, have shown continual decline in the cropland after reaching peak levels. The cropland trajectories in high biophysically suitable regions, e.g., Corn Belt, have stabilized after reaching peak levels. In the Western United States, low-intensity crop cover (〈10 %) is sustained with irrigation support. A slower rate of land conversion was found in the industrial period. Significant effect of Conservation Reserve Program on planted crop area is found in last two decades (1990–2010). Content Type Journal Article Category Report Pages 1-13 DOI 10.1007/s13280-012-0354-6 Authors Sanjiv Kumar, Center for Ocean-Land-Atmosphere Studies, 4041 Powder Mill Road, Suite 302, Calverton, MD 20705, USA Venkatesh Merwade, School of Civil Engineering, Purdue University, 550 Stadium Mall Dr., West Lafayette, IN 47907, USA P. Suresh C. Rao, School of Civil Engineering, Purdue University, 550 Stadium Mall Dr., West Lafayette, IN 47907, USA Bryan C. Pijanowski, Department of Forestry and Natural Resources, Purdue University, 195 Marsteller Street, West Lafayette, IN 47906, USA Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description: Vertical diffusivity and oxygen consumption in the basin water, the water below the sill level at about 59 m depth, have been estimated by applying budget methods to monitoring data from hydrographical stations BY4 and BY5 for periods without water renewal. From the vertical diffusivity, the mean rate of work against the buoyancy forces below 65 m depth is estimated to about 0.10 mW m−2. This is slightly higher than published values for East Gotland Sea. The horizontally averaged vertical diffusivity κ can be approximated by the expression κ = a _0 N −1 where N is the buoyancy frequency and a _0 ≈ 1.25 × 10−7 m2 s−2, which is similar to values for a _0 used for depths below the halocline in Baltic proper circulation models for long-term simulations. The contemporary mean rate of oxygen consumption in the basin water is about 75 g O_2 m−2 year−1, which corresponds to an oxidation of 28 g C m−2 year−1. The oxygen consumption in the Bornholm Basin doubled from the 1970s to the 2000s, which qualitatively explains the observed increasing frequency and vertical extent of anoxia and hypoxia in the basin water in records from the end of the 1950s to present time. A horizontally averaged vertical advection–diffusion model of the basin water is used to calculate the effects on stratification and oxygen concentration by a forced pump-driven vertical convection. It is shown that the residence time of the basin water may be reduced by pumping down and mixing the so-called winter water into the deepwater. With the present rate of oxygen consumption, a pumped flux of about 25 km3 year−1 would be sufficient to keep the oxygen concentration in the deepwater above 2 mL O_2 L−1. ©2012 The Author(s)

Description: We relate the historical (1850–2000) spatial and temporal changes in cropland cover in the conterminous United States to several socio-economic and biophysical determinants using an eco-region based spatial framework. Results show population density as a major determinant during the nineteenth century, and biophysical suitability as the major determinant during the twentieth century. We further examine the role of technological innovations, socio-economic and socio-ecological feedbacks that have either sustained or altered the cropland trajectories in different eco-regions. The cropland trajectories for each of the 84 level-III eco-regions were analyzed using a nonlinear bi-analytical model. In the Eastern United States, low biophysically suitable eco-regions, e.g., New England, have shown continual decline in the cropland after reaching peak levels. The cropland trajectories in high biophysically suitable regions, e.g., Corn Belt, have stabilized after reaching peak levels. In the Western United States, low-intensity crop cover (〈10 %) is sustained with irrigation support. A slower rate of land conversion was found in the industrial period. Significant effect of Conservation Reserve Program on planted crop area is found in last two decades (1990–2010). ©2012 Royal Swedish Academy of Sciences

Description:    Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security. Content Type Journal Article Category Perspective Pages 1-8 DOI 10.1007/s13280-012-0353-7 Authors Sybil P. Seitzinger, International Geosphere Biosphere Programme, Royal Swedish Academy of Sciences, Box 50005, 104 05 Stockholm, Sweden Uno Svedin, Stockholm Resilience Centre, 106 91 Stockholm, Sweden Carole L. Crumley, Department of Archaeology and Ancient History, Uppsala University, 75126 Uppsala, Sweden Will Steffen, Stockholm Resilience Centre, 106 91 Stockholm, Sweden Saiful Arif Abdullah, Institute for Environment and Development (LESTARI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia Christine Alfsen, Chemin du Vier, 06380 Sospel, France Wendy J. Broadgate, International Geosphere Biosphere Programme, Royal Swedish Academy of Sciences, Box 50005, 104 05 Stockholm, Sweden Frank Biermann, Institute for Environmental Studies (IVM), VU University Amsterdam, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands Ninad R. Bondre, International Geosphere Biosphere Programme, Royal Swedish Academy of Sciences, Box 50005, 104 05 Stockholm, Sweden John A. Dearing, Geography and Environment, University of Southampton, Southampton, SO17 1BJ UK Lisa Deutsch, Stockholm Resilience Centre, 106 91 Stockholm, Sweden Shobhakar Dhakal, Energy Field of Study, Asian Institute of Technology, PO Box 4, Klong Luang, Pathumthani, 12120 Thailand Thomas Elmqvist, Stockholm Resilience Centre, 106 91 Stockholm, Sweden Neda Farahbakhshazad, Swedish Secretariat for Environmental Earth System Sciences, The Royal Swedish Academy of Sciences, Box 50005, 104 05 Stockholm, Sweden Owen Gaffney, International Geosphere Biosphere Programme, Royal Swedish Academy of Sciences, Box 50005, 104 05 Stockholm, Sweden Helmut Haberl, Institute of Social Ecology Vienna, Alpen-Adria Universität Klagenfurt, Schottenfeldgasse 29, 1070 Vienna, Austria Sandra Lavorel, Laboratoire d’Ecologie Alpine, CNRS UMR 5553, BP 53, 2233 Rue de la Piscine, 38041 Grenoble Cedex 9, France Cheikh Mbow, Institut des Sciences de l’Environment, Laboratoired’Enseignementet de Recherche en Géomatique (LERG), Ecole Supérieure Polytechnique (ESP)/FST, Université Cheikh Anta Diop, Dakar, Senegal Anthony J. McMichael, National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT 0200, Australia Joao M. F. deMorais, International Geosphere Biosphere Programme, Royal Swedish Academy of Sciences, Box 50005, 104 05 Stockholm, Sweden Per Olsson, Stockholm Resilience Centre, 106 91 Stockholm, Sweden Patricia Fernanda Pinho, IGBP Regional Office Brazil, Brazil Instituto Nacional de Pesquisas Espaciais, São José dos Campos, Brazil Karen C. Seto, Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT 06511, USA Paul Sinclair, Department of Archaeology and Ancient History, Uppsala University, 75126 Uppsala, Sweden Mark Stafford Smith, CSIRO Climate Adaptation Flagship, Canberra, ACT 2601, Australia Lorraine Sugar, The World Bank Group, 1818 H Street NW, Washington, DC 20433, USA Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description:    Megacities are not only important drivers for socio-economic development but also sources of environmental challenges. Many megacities and large urban agglomerations are located in the coastal zone where land, atmosphere, and ocean meet, posing multiple environmental challenges which we consider here. The atmospheric flow around megacities is complicated by urban heat island effects and topographic flows and sea breezes and influences air pollution and human health. The outflow of polluted air over the ocean perturbs biogeochemical processes. Contaminant inputs can damage downstream coastal zone ecosystem function and resources including fisheries, induce harmful algal blooms and feedback to the atmosphere via marine emissions. The scale of influence of megacities in the coastal zone is hundreds to thousands of kilometers in the atmosphere and tens to hundreds of kilometers in the ocean. We list research needs to further our understanding of coastal megacities with the ultimate aim to improve their environmental management. Content Type Journal Article Category Review Pages 1-16 DOI 10.1007/s13280-012-0343-9 Authors Roland von Glasow, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Tim D. Jickells, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Alexander Baklanov, Danish Meteorological Institute, Copenhagen, Denmark Gregory R. Carmichael, Department of Chemical & Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USA Tom M. Church, School of Marine Science and Policy, University of Delaware, Newark, DE 19716-3501, USA Laura Gallardo, Departamento de Geofísica & Centro de Modelamiento Matemático, Universidad de Chile, Blanco Encalada 2002, Piso 4, Santiago, Chile Claire Hughes, Environment Department, University of York, Heslington, York, YO10 5DD UK Maria Kanakidou, Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, 71003 Heraklion, Greece Peter S. Liss, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Laurence Mee, Scottish Marine Institute, Scottish Association for Marine Science (SAMS), Oban, Argyll, PA37 1QA UK Robin Raine, The Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland, Galway, Ireland Purvaja Ramachandran, Institute for Ocean Management, Anna University, Chennai, 600 025 India R. Ramesh, Institute for Ocean Management, Anna University, Chennai, 600 025 India Kyrre Sundseth, Center for Ecology and Economics (CEE), NILU-Norwegian Institute for Air Research, Instituttveien 18, P.O. Box 100, 2007 Kjeller, Norway Urumu Tsunogai, Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan Mitsuo Uematsu, Center for International Collaboration, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan Tong Zhu, State Key Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871 China Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description: Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security. ©2012 The Author(s)