Urban Ecology and Global Climate Change. Группа авторов

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Urban Ecology and Global Climate Change - Группа авторов


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Agriculture University, Bhagalpur, Bihar, India

      Humankind is facing three major challenges viz. human overpopulation, urbanisation, and climate change with the onset of the twenty‐first century (Steiner 2014). Presently, about seven billion (expected to reach 8.2 and 9 billion by 2025 and 2050, respectively) people are inhabiting the Earth which is more than any previous time. Urban areas and people living in the cities are increasing rapidly in size, globally (Mitchell et al. 2018). Over half (~54%) of the world's population is residing in the urban areas which is expected to grow to 60 and 80% by the year 2030 and 2050, respectively (Lee 2011; Vasishth 2015). Urbanisation phenomenon can be seen occurring on all the continents (except Antarctica); however, rapid urbanisation is happening, particularly in the Asia and Sub‐Saharan Africa (Yu et al. 2017). Rapid urbanisation is putting severe stress on the planet Earth resulting in changes in the ecosystems from the landscape to the global scales (Steiner 2014; Colding and Barthel 2017). Urbanisation leads to the rapid conversion of natural pervious land surfaces to various impervious surfaces in the built forms like buildings and roads which resulted in changes in many ecosystem functions such as water infiltration and availability, species composition, soil properties, and thermal properties of the surfaces (Gaston et al. 2010; Seto et al. 2012; Yu et al. 2017). Urbanisation has not only affected the tangible features of the natural ecosystems but also resulted in the modifications of intangible aspects such as biogeochemical cycling and climate change (Kattel et al. 2013; Mitchell et al. 2018). Therefore, need for the proper planning and designing of the urban ecosystems has been arisen for reducing the ecological footprints (on per capita basis) of these ecosystems for managing the trio of challenges mentioned in the opening line of this chapter (Steiner 2014; Vasishth 2015).

      1.1.1 Urban Ecology

      Nowadays most of the people live in the urban areas; however, they have limited understanding of the benefits derived from the interaction with the natural systems within the cities. Urban ecology is a scientific discipline which integrates a number of concepts from the natural and social sciences along with the landscape approach and ecosystems services at its core (Alberti 2008; Niemelä et al. 2011; Niemelä 2014) and represents the ‘holistic ecology of urban areas’ (McDonnell et al. 2009; Jim 2011). Since this field is still emerging, its hypotheses, models, and theories are still in the process of testing and validation (Niemelä 2014). Since human activities are the dominant factors in shaping the urban ecosystems, the urban ecology unintentionally revolves around the processes and interactions attributed by the human actions (Verma et al. 2020a). For example, urban ecology helps in recognising the restorative behaviour of humans for the natural ecosystems and elucidating the mechanisms responsible for the structuring of urban communities during the process of urbanisation (Steiner 2014; Duffy and Chown 2016). However, poor understanding of the complex interactions between the socio‐ecological and infrastructural developments in the urban ecosystems resulted in the social disharmony in the long term (Kattel et al. 2013). Therefore, Kattel et al. (2013) suggested a concept of complementary framework for urban ecology which represents the development of infrastructure and green spaces in an integrated manner to derive utmost ecosystem services. For instance, integrated development of flora and fauna along with the urban buildings, roads, and railway tracks for providing the utmost scope for the interactions between human inhabitants and wider communities through inter‐habitat‐community systems (Halpern et al. 2008).

      An urban ecosystem is composed of several tangible and intangible components. Tangible components include the physical structures which can be natural (such as flora and fauna, water bodies, mountains, urban agriculture, etc.) or human‐made (such as built structures like buildings and building materials, roads, railways, health, and related infrastructural developments; energy sources like coal, liquified petroleum gas (LPG), wood; food supplies and waste generation, etc.). In addition, the intangible components include the ecosystems services derived from various natural systems, biogeochemical cycling, solar energy, and material flow in the urban areas (Verma et al. 2020a). These major components can be mainly divided into three sectors: (i) urban infrastructures associated with the urban heat island (UHI) effect; (ii) urban vegetation representing the green spaces and related ecosystem services; and (iii) urban metabolism which represents the flow of energy and materials within the urban ecosystems.

      1.2.1 Urban (Built) Infrastructures


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