Description:    Globally, urban growth will add 1.5 billion people to cities by 2030, making the difficult task of urban water provisions even more challenging. In this article, we develop a conceptual framework of urban water provision as composed of three axes: water availability, water quality, and water delivery. For each axis, we calculate quantitative proxy measures for all cities with more than 50,000 residents, and then briefly discuss the strategies cities are using in response if they are deficient on one of the axes. We show that 523 million people are in cities where water availability may be an issue, 890 million people are in cities where water quality may be an issue, and 1.3 billion people are in cities where water delivery may be an issue. Tapping into groundwater is a widespread response, regardless of the management challenge, with many cities unsustainably using this resource. The strategies used by cities deficient on the water delivery axis are different than for cities deficient on the water quantity or water quality axis, as lack of financial resources pushes cities toward a different and potentially less effective set of strategies. Content Type Journal Article Pages 1-10 DOI 10.1007/s13280-011-0152-6 Authors Robert I. McDonald, Worldwide Office, The Nature Conservancy, 4245 N. Fairfax Drive, Arlington, VA 22203, USA Ian Douglas, School of Environment and Development, University of Manchester, Oxford Road, Manchester, M13 9PL UK Carmen Revenga, Worldwide Office, The Nature Conservancy, 4245 N. Fairfax Drive, Arlington, VA 22203, USA Rebecca Hale, School of Life Sciences, Arizona State University, 1711 South Rural Road, Tempe, AZ 85287, USA Nancy Grimm, Faculty of Ecology, Evolution, & Environmental Science, Arizona State University, 1711 South Rural Road, Tempe, AZ 85287, USA Jenny Grönwall, 110 Marlyn Lodge, Portsoken St, London, E1 8RB UK Balazs Fekete, CUNY Research Foundation, The City College of New York, 160 Convent Avenue, New York, NY 10031, USA Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description:    Geoengineering methods are intended to reduce climate change, which is already having demonstrable effects on ecosystem structure and functioning in some regions. Two types of geoengineering activities that have been proposed are: carbon dioxide (CO 2 ) removal (CDR), which removes CO 2 from the atmosphere, and solar radiation management (SRM, or sunlight reflection methods), which reflects a small percentage of sunlight back into space to offset warming from greenhouse gases (GHGs). Current research suggests that SRM or CDR might diminish the impacts of climate change on ecosystems by reducing changes in temperature and precipitation. However, sudden cessation of SRM would exacerbate the climate effects on ecosystems, and some CDR might interfere with oceanic and terrestrial ecosystem processes. The many risks and uncertainties associated with these new kinds of purposeful perturbations to the Earth system are not well understood and require cautious and comprehensive research. Content Type Journal Article Category Review Paper Pages 1-20 DOI 10.1007/s13280-012-0258-5 Authors Lynn M. Russell, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Dr. Mail Code 0221, La Jolla, CA 92093-0221, USA Philip J. Rasch, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P. O. Box 999, MSIN K9-34, Richland, WA 99352, USA Georgina M. Mace, Centre for Population Biology, Imperial College London, Ascot, Berks SL5 7PY, UK Robert B. Jackson, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA John Shepherd, Earth System Science, School of Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH UK Peter Liss, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Margaret Leinen, Harbor Branch Oceanographic Institute, 5600 US Rt 1 North, Fort Pierce, FL 34946, USA David Schimel, NEON Inc, 1685 38th Street, Boulder, CO 80305, USA Naomi E. Vaughan, Tyndall Centre for Climate Change Research, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK Anthony C. Janetos, Joint Global Change Research Institute Pacific Northwest National Laboratory/University of Maryland, 5825 University Research Court, Suite 3500, College Park, MD 20740, USA Philip W. Boyd, NIWA Centre of Chemical & Physical Oceanography, Department of Chemistry, University of Otago, Dunedin, New Zealand Richard J. Norby, Environmental Sciences Division, Oak Ridge National Laboratory, Bethel Valley Road, Bldg. 2040, MS-6301, Oak Ridge, TN 37831-6301, USA Ken Caldeira, Department of Global Ecology, Carnegie Institution, Stanford, CA 94305, USA Joonas Merikanto, Division of Atmospheric Sciences, Department of Physics, University of Helsinki, P.O Box 64, 00014 Helsinki, Finland Paulo Artaxo, Institute of Physics, University of São Paulo, Rua do Matão, Travessa R, 187, São Paulo, SP CEP 05508-090, Brazil Jerry Melillo, The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA M. Granger Morgan, Department of Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description:    Nitrous oxide (N 2 O) emissions from grazed grasslands are estimated to be approximately 28% of global anthropogenic N 2 O emissions. Estimating the N 2 O flux from grassland soils is difficult because of its episodic nature. This study aimed to quantify the N 2 O emissions, the annual N 2 O flux and the emission factor (EF), and also to investigate the influence of environmental and soil variables controlling N 2 O emissions from grazed grassland. Nitrous oxide emissions were measured using static chambers at eight different grasslands in the South of Ireland from September 2007 to August 2009. The instantaneous N 2 O flux values ranged from -186 to 885.6 μg N 2 O-N m −2  h −1 and the annual sum ranged from 2 ± 3.51 to 12.55 ± 2.83 kg N 2 O-N ha −1  y −1 for managed sites. The emission factor ranged from 1.3 to 3.4%. The overall EF of 1.81% is about 69% higher than the Intergovernmental Panel on Climate Change (IPCC) default EF value of 1.25% which is currently used by the Irish Environmental Protection Agency (EPA) to estimate N 2 O emission in Ireland. At an N applied of approximately 300 kg ha −1  y −1 , the N 2 O emissions are approximately 5.0 kg N 2 O-N ha −1 y −1 , whereas the N 2 O emissions double to approximately 10 kg N ha −1 for an N applied of 400 kg N ha −1  y −1 . The sites with higher fluxes were associated with intensive N-input and frequent cattle grazing. The N 2 O flux at 17°C was five times greater than that at 5°C. Similarly, the N 2 O emissions increased with increasing water filled pore space (WFPS) with maximum N 2 O emissions occurring at 60–80% WFPS. We conclude that N application below 300 kg ha −1  y −1 and restricted grazing on seasonally wet soils will reduce N 2 O emissions. Content Type Journal Article Pages 1-20 DOI 10.1007/s10021-011-9434-x Authors Rashad Rafique, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Deirdre Hennessy, Department of Animals &, Grassland Science Research, Teagasc-Moorpark, Fermoy, Ireland Gerard Kiely, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840

Description:    Before climate change is considered in long-term coastal management, it is necessary to investigate how institutional stakeholders in coastal management conceptualize climate change, as their awareness will ultimately affect their actions. Using questionnaires in eight Baltic Sea riparian countries, this study examines environmental managers’ awareness of climate change. Our results indicate that problems related to global warming are deemed secondary to short-term social and economic issues. Respondents agree that problems caused by global warming will become increasingly important, but pay little attention to adaptation and mitigation strategies. Current environmental problems are expected to continue to be urgent in the future. We conclude that an apparent gap exists between decision making, public concerns, and scientific consensus, resulting in a situation in which the latest evidence rarely influences commonly held opinions. Content Type Journal Article Pages 645-655 DOI 10.1007/s13280-012-0327-9 Authors Joanna Piwowarczyk, Department of Marine Ecology, Institute of Oceanology, Polish Academy of Sciences, 55 Powstancow Warszawy Street, 81-712 Sopot, Poland Anders Hansson, Centre for Climate Science and Policy Research and Water and Environmental Studies, Department of Thematic Studies, Linköping University, Norrköping, Sweden Mattias Hjerpe, Centre for Climate Science and Policy Research and Water and Environmental Studies, Department of Thematic Studies, Linköping University, Norrköping, Sweden Boris Chubarenko, Atlantic Branch of the Institute of Oceanology, Russian Academy of Sciences, Kaliningrad, Russia Konstantin Karmanov, Atlantic Branch of the Institute of Oceanology, Russian Academy of Sciences, Kaliningrad, Russia Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447 Journal Volume Volume 41 Journal Issue Volume 41, Number 6

Description:    Under increasing water scarcity, collective groundwater management is a global concern. This article presents an interdisciplinary analysis of this challenge drawing on a survey including 50 large and small farms and gardens in a village in an agricultural land reclamation area on the edge of the Western Desert of Egypt. Findings revealed that smallholders rely on a practice of shallow groundwater use, through which drainage water from adjacent irrigation areas is effectively recycled within the surface aquifer. Expanding agroindustrial activities in the surrounding area are socio-economically important, but by mining non-renewable water in the surrounding area, they set in motion a degradation process with social and ecological consequences for all users in the multi-layered aquifer system. Based on the findings of our investigation, we identify opportunities for local authorities to more systematically connect available environmental information sources and common pool resource management precedents, to counterbalance the degradation threat. Content Type Journal Article Category Report Pages 1-14 DOI 10.1007/s13280-012-0255-8 Authors Caroline King, Oxford University Centre for the Environment, University of Oxford, South Parks Road, Oxford, UK Boshra Salem, Department of Environmental Sciences, Faculty of Science, University of Alexandria, Alexandria, Egypt Journal AMBIO: A Journal of the Human Environment Online ISSN 1654-7209 Print ISSN 0044-7447

Description:    Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH 4 emissions reduced in favor of greater CO 2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on N 2 O or global warming potential. We report greenhouse gas fluxes (CH 4 , CO 2 , N 2 O) from a drained peatland in the Sacramento-San Joaquin River Delta, California, USA currently managed as a rangeland (that is, pasture). This ecosystem was a net source of CH 4 (25.8 ± 1.4 mg CH 4 -C m −2  d −1 ) and N 2 O (6.4 ± 0.4 mg N 2 O-N m −2  d −1 ). Methane fluxes were comparable to those of other managed temperate peatlands, whereas N 2 O fluxes were very high; equivalent to fluxes from heavily fertilized agroecosystems and tropical forests. Ecosystem scale CH 4 fluxes were driven by “hotspots” (drainage ditches) that accounted for less than 5% of the land area but more than 84% of emissions. Methane fluxes were unresponsive to seasonal fluctuations in climate and showed minimal temporal variability. Nitrous oxide fluxes were more homogeneously distributed throughout the landscape and responded to fluctuations in environmental variables, especially soil moisture. Elevated CH 4 and N 2 O fluxes contributed to a high overall ecosystem global warming potential (531 g CO 2 -C equivalents m −2  y −1 ), with non-CO 2 trace gas fluxes offsetting the atmospheric “cooling” effects of photoassimilation. These data suggest that managed Delta peatlands are potentially large regional sources of greenhouse gases, with spatial heterogeneity in soil moisture modulating the relative importance of each gas for ecosystem global warming potential. Content Type Journal Article Pages 1-15 DOI 10.1007/s10021-011-9411-4 Authors Yit Arn Teh, Environmental Change Research Group, School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9 AL Scotland, UK Whendee L. Silver, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Oliver Sonnentag, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Matteo Detto, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Maggi Kelly, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Dennis D. Baldocchi, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840