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Arlington, VA, United States

McDonald R.I.,Worldwide Office | Forman R.T.T.,Harvard University | Kareiva P.,Seattle Office

Urban growth reduces open space in and around cities, impacting biodiversity and ecosystem services. Using land-cover and population data, we examined land consumption and open space loss between 1990 and 2000 for all 274 metropolitan areas in the contiguous United States. Nationally, 1.4 million ha of open space was lost, and the amount lost in a given city was correlated with population growth (r(272) = 0.85, P<0.001). In 2000, cities varied in per capita land consumption by an order of magnitude, from 459 m2/person in New York to 5393 m2/person in Grand Forks, ND. The per capita land consumption (m2/person) of most cities decreased on average over the decade from 1,564 to 1,454 m2/person, but there was substantial regional variation and some cities even increased. Cities with greater conservation funding or more reformminded zoning tended to decrease in per capita land consumption more than other cities. The majority of developed area in cities is in low-density neighborhoods housing a small proportion of urban residents, with Gini coefficients that quantify this developed land inequality averaging 0.63. Our results suggest conservation funding and reform-minded zoning decrease per capita open space loss. © 2010 McDonald et al. Source

McDonald R.I.,Worldwide Office
Annals of the New York Academy of Sciences

Globally, urbanization is rapidly growing cities and towns at a historically unprecedented rate, and this rapid urban growth is influencing many facets of the environment. This paper reviews the effectiveness of conservation interventions that are designed to increase urban sustainability. It presents evidence for an apparent urban-environmental paradox: while the process of urban growth converts natural habitat to other land covers and degrades natural resources and ecosystem function, the increase in human population can increase demand for natural resources and ecosystem services. The fundamental problem that many conservation interventions try to address is that most facets of the environment are common or public goods, and are hence undervalued in decision making (market failure). The paper presents a threefold classification of conservation interventions in cities: conservation in the city (protecting biodiversity), conservation by the city (reducing per capita resource and energy use), and conservation for cities (projects that maintain or enhance ecosystem services). It ends by discussing methods for spatially targeting conservation interventions of all three types and for quantifying the effectiveness of interventions retrospectively. © 2015 New York Academy of Sciences. Source

McDonald R.I.,Worldwide Office | Douglas I.,University of Manchester | Revenga C.,Worldwide Office | Hale R.,Arizona State University | And 3 more authors.

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. © Royal Swedish Academy of Sciences 2011. Source

McDonald R.I.,Worldwide Office | Olden J.D.,University of Washington | Opperman J.J.,Freshwater Focal Area Program | Miller W.M.,Northwestern University | And 4 more authors.

Rising energy consumption in coming decades, combined with a changing energy mix, have the potential to increase the impact of energy sector water use on freshwater biodiversity. We forecast changes in future water use based on various energy scenarios and examine implications for freshwater ecosystems. Annual water withdrawn/manipulated would increase by 18-24%, going from 1,993,000-2,628,000 Mm3 in 2010 to 2,359,000-3,271,000 Mm3 in 2035 under the Reference Case of the Energy Information Administration (EIA). Water consumption would more rapidly increase by 26% due to increased biofuel production, going from 16,700-46,400 Mm3 consumption in 2010 to 21,000-58,400 Mm3 consumption in 2035. Regionally, water use in the Southwest and Southeast may increase, with anticipated decreases in water use in some areas of the Midwest and Northeast. Policies that promote energy efficiency or conservation in the electric sector would reduce water withdrawn/manipulated by 27-36 m3GJ-1 (0.1-0.5 m3GJ-1 consumption), while such policies in the liquid fuel sector would reduce withdrawal/manipulation by 0.4-0.7 m3GJ-1 (0.2-0.3 m3GJ-1 consumption). The greatest energy sector withdrawal/manipulation are for hydropower and thermoelectric cooling, although potential new EPA rules that would require recirculating cooling for thermoelectric plants would reduce withdrawal/manipulation by 441,000 Mm3 (20,300 Mm3 consumption). The greatest consumptive energy sector use is evaporation from hydroelectric reservoirs, followed by irrigation water for biofuel feedstocks and water used for electricity generation from coal. Historical water use by the energy sector is related to patterns of fish species endangerment, where water resource regions with a greater fraction of available surface water withdrawn by hydropower or consumed by the energy sector correlated with higher probabilities of imperilment. Since future increases in energy-sector surface water use will occur in areas of high fish endemism (e.g., Southeast), additional management and policy actions will be needed to minimize further species imperilment. © 2012 McDonald et al. Source

McDonald R.I.,Worldwide Office | Weber K.,Worldwide Office | Padowski J.,Stanford University | Florke M.,University of Kassel | And 9 more authors.
Global Environmental Change

Urban growth is increasing the demand for freshwater resources, yet surprisingly the water sources of the world's large cities have never been globally assessed, hampering efforts to assess the distribution and causes of urban water stress. We conducted the first global survey of the large cities' water sources, and show that previous global hydrologic models that ignored urban water infrastructure significantly overestimated urban water stress. Large cities obtain 78±3% of their water from surface sources, some of which are far away: cumulatively, large cities moved 504 billion liters a day (184km3yr-1) a distance of 27,000±3800km, and the upstream contributing area of urban water sources is 41% of the global land surface. Despite this infrastructure, one in four cities, containing $4.8±0.7 trillion in economic activity, remain water stressed due to geographical and financial limitations. The strategic management of these cities' water sources is therefore important for the future of the global economy. © 2014 The Authors. Source

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