Content uploaded by Felisa A Smith
Author content
All content in this area was uploaded by Felisa A Smith on Dec 01, 2016
Content may be subject to copyright.
A preview of the PDF is not available
Megacities and the environment
The Scientific World Journal
Abstract
This paper reviews the available data and models on energy and material flows through the world's 25 largest cities. Throughput is categorized as stored, transformed, or passive for the major flow modes. The aggregate, fuel, food, water, and air cycles are all examined. Emphasis is placed on atmospheric pathways because the data are abundant. Relevant models of urban energy and material flows, demography, and atmospheric chemistry are discussed. Earth system--level loops from cities to neighboring ecosystems are identified. Megacities are somewhat independent of their immediate environment for food, fuel, and aggregate inputs, but all are constrained by their regional environment for supplying water and absorbing wastes. We elaborate on analogies with biological metabolism and ecosystem succession as useful conceptual frameworks for addressing urban ecological problems. We conclude that whereas data are numerous for some individual cities, cross-cutting compilations are lacking in biog...
... Coastal pollution includes organic chemicals, heavy metals, pharmaceuticals and sludge that contribute to deformity, disease and death of marine organisms (Decker et al., 2002). Despite efforts to holistically manage coastal pollution through integrated coastal management schemes that have been widely adopted to promote sustainable development of coastal areas, runoff has continued to increase. ...
The World Ocean System (WOS) is the ensemble of interconnected oceans and seas around
the world. The WOS contains not only the sea surface – which makes up over 70 percent
of Earth’s surface, but also the water column, the sea floor and the sub-sea floor, all of
which together provide the largest overall living space, habitat, on the planet (see, e.g.,
Haedrich, 1996). Indeed, most of Earth’s “ecosystem services” come from marine systems
(Costanza, 2000). Ecosystem services are direct and indirect benefits of environmental systems
to people (Hassan et al., 2005) in four categories: provisioning, regulating, cultural and
supporting services. For example, the World Ocean provides fish for us to eat (see Chapter
40), it regulates the climate (see Chapter 32), provides the basis of the hydrologic cycle that
brings freshwater to us, and provides spiritual, educational, economic and recreational opportunities
for people around the world. Perhaps most importantly, the World Ocean cycles
nutrients and elements, such as carbon, thereby supporting all the other ecosystem services.
Figure 39.1 shows all four ecosystem services, including supporting services and their benefits
to humanity.
... Newman (1999, p. 220) asserts that the view of a city as an ecosystem is "one of the strongest themes running through the literature on urban sustainability". Baccini (1996), Nijkamp and Pepping (1998) and Decker et al. (2002) contend that the focus on urban sustainability is because cities are the major consumers of natural resources and producers of wastes. Implicitly, these assertions necessitate a transformation of the city from a less, to a more, sustainable form. ...
This paper reviews the main bodies of contemporary urban sustainability theory. From this analysis, two underpinning paradigms of urban sustainability are identified: (1) The 'Human Exemptionalism Paradigm' (HEP), which emphasizes the ability of humans to overcome environmental problems-see Urban Sociology, Urban Ecology, Urban Geography, Urban Psychology and Political Economy; and (2) The 'New Ecological Paradigm' (NEP), which emphasizes the criticality of ecological limits to human progress-see Urban Metabolism, Energy/Emergy Analysis and Ecological Footprinting. Each of these approaches is critically reviewed, highlighting their main assumptions, theoretical and practical foci. It is argued in the paper that if the related issues of urban sustainability and development are to be progressed, there needs to be: (1) a greater maturation of the NEP approaches, which are 'relative newcomers' to the area of urban theory; and (2) greater integration and dialogue between the HEP and NEP approaches to urban sustainability than has hitherto been the case.
The interconnection of urbanization trends and environmental pressures, are due to the rising demand for resource consumption, waste production and greenhouses gas emissions. Taking into consideration the massive reduction of natural resources, the deprivation of the life quality and the climate change, the scientific community indicates the necessity to emphasis and understand the relationship between cities and the environment as a dynamic concept. Consequently, cities are facing the challenge to implement alternative strategies towards more sustainable management of urban resources. This research aims to shed light on the concept of urban metabolism, the methods that are been used to gauge urban metabolism (i.e Emergy Analysis, Material Flow Analysis, Ecological Footprint etc.), as well as the assessment of the proposed methodologies through SWOT analysis and Analytical Hierocracy Process, considering multi-criteria analysis and how those reflect to Circular Economy and European Green Deal Strategy. The results showed that, the existing methodologies needs refreshment to cover the needs for the cities of tomorrow and a new hybrid approach which will include new set of Key Performed Indicators is essential. Furthermore, the results could serve as a beneficial reference point for policy makers, consultants, rural developers as the new hybrid approach can be used to measure and assess the level of metabolism in one area in order to prevent future expansion.
There is an abundance of conceptual frameworks relevant to sustainability in urban systems. However, to advance urban ecological science and its application to sustainable urban transformations, key existing frameworks must be synthesized. This paper is a conceptual synthesis cast in essay form in order to encompass a broad range of relevant ideas. It starts from the premise that the familiar models of metropolitan and megalopolitan urban structure, of industrially driven urban development, and of the contrasts between urban and non-urban lands are manifestly inadequate representations of evolving global reality. Such inadequacy is illustrated with examples from the United States and from China. Both the form and the interactions involved in contemporary urbanization and urban change suggest the need for a new integrated framework synthesizing two existing yet still evolving concepts: (1) The urban megaregion framework accommodates the spatial extent, interdigitation of contrasting land uses, and the linked spatial relations between nominally urban and nominally rural areas. (2) The new concept of the continuum of urbanity emphasizes the shifts in livelihood and lifestyle driven by regional and global teleconnections and their joint effects on local environments and landscapes. Together these frameworks suggest a common conceptual structure for addressing urban areas of different ages, sizes, forms, and dynamics in both urbanizing and urbanized areas in developing and developed countries and regions. The synthesis of frameworks points to empirical research needs, and has the potential to better match sustainability plans and actions with the diverse urban forms and dynamics now appearing around the world.
ResearchGate has not been able to resolve any references for this publication.