Sustainable development and urban carrying capacity 

Mumbai: “In recent years, there has been lot of discussion concerning the CC of the earth for humans, and the ultimate limit to global CC for economic development.”

By Debapriya Mukherjee
Former Senior Scientist
Central Pollution Control Board, India

Negative effects of tourism development in any destination are usually due to the high concentration of tourists, accommodation facilities and the activities in a relatively restricted area. One of the most important measures to protect the areas concerned is to calculate the maximum number of tourists that can simultaneously, be accommodated vehicles that can be permitted and sport activities that can be allowed there. This is called the Carrying Capacity (CC). In Sri Lanka, the CC of important tourist cities may have already been exceeded as opined by academicians. The policy-makers have still not given serious thought to formulating a strategic long-term plan for sustainable urban tourism development for the cities and specific attractions in the country. Thereby there is a need to address issues related to the concept of CC. If the government is going to target millions of tourists in the important cities, the CC must be evaluated in advance.

The latest definitions of CC for protected areas, such as national parks, fragile ecosystem and wilderness areas, centre on the acceptability of natural resource and human impacts of visitation. The biophysical characteristics of a protected area (soils, topography and vegetation), social factors (location and mode of travel, season of use, group size, and behaviour of visitors), and management policies (visitor use restrictions) are more important determinants of CC than the number of visitors. It is true that good progress has been made in evaluating CC, but in many cases the methods adopted for evaluating CC are non-quantitative and lack of analytical rigour. The CC decisions will be easier to take if based on the quantitative method. which helps decision-makers/managers (responsible for protecting eco-sensitive zones) to determine quantitatively whether the current state of target ecosystem conforms to the established CC standards. It is pertinent to mention here that the restriction of the evaluation of CC of only to protected areas/eco-sensitive zones will not be very effective in that the high ecological pressure in urban areas and changing land-use patterns caused by advancing modern lifestyles would have indirect influence on protected areas as cities close to these eco-sensitive zones, continue to experience population expansion, consumption growth, resource overuse, waste and emission accumulation and many more. Therefore, it is very important to evaluate the CC of cities that do not conform to the accepted standards. 

 The concept of CC is widely discounted, in part because it is fluid and virtually unquantifiable. Past discoveries and technological breakthroughs have raised CC, and western science encourages the belief that technology’s potential is unlimited. Technological optimists typically reject scientific warnings that there are no substitutes exist for topsoil, fresh water, clean air, and the “free services” of many species, or that technology and its deployment to replace existing uses of petrochemical energy will take at least 20 years to be effective.  

Although there has been a tremendous advancement of science and technology, humans consistently rely on the overuse of natural resources for survival. Expansive urbanization associated with rapid industrialization causes enormous pressure on the Earth’s resources, and humans’ requirements for resources have surpassed the planet’s regeneration capacity since the 1970s. Thus, it is essential to determine urban carrying capacity (UCC) to ensure the safety of ecosystems and their sustainable development, or at least to slow down the degradation of natural capital.

Environmental and socio-economic factors coexist with each other to support urban sustainable development. On the one hand, the economic foundation promotes social progress, and provides the technological instrument and material foundation necessary for the development and utilization of resources and the environment. On the other hand, resources and the environment provide production and living materials necessary for the development of economic and social activities, and absorb waste products. Exploring the mechanism of internal interaction between environmental and socio-economic factors is considered helpful in diagnosing and compensating the shortcomings of the UCC framework and constructing an early-warning mechanism. In addition, such analysis would be helpful in optimizing the allocation of resources, as well as the environmental, economic, societal, transportation, and other factors. This way, the coupling and coordination of each city’s CC could be promoted, and regionally coordinated development realized. 

UCC analysis helps measure the interaction between human activities and urban resources environment system and provides foundational knowledge of sustainability, vulnerability, and resilience of land use and address the issues related to land-cover and land-use changes for the purpose of human welfare. Relationships are supported by means of information flow, capital flow, material flow, and energy flow.

For this purpose, the emergent need is to develop research variables (or “carriers” in the present context), methods, and approaches regarding the construction and evaluation of a comprehensive UCC index system against various backdrops. Carriers are water, land, transportation, human CC, resources and factors that are environmental, ecological, social and economic.  An appropriate technique is to be employed to examine the dynamic relationships between the carrying capacities. Researchers already constructed an urban comprehensive CC index in different cities of the world and their findings revealed that transportation CC was the most important driving force among the other subsystems that interact with each other.  Also, Land-Cover and Land-Use Change Programme was designed to improve the understanding of human interactions with the environment.

In recent years, there has been lot of discussion concerning the CC of the earth for humans, and the ultimate limit to global CC for economic development. Thereby a measurement of comprehensive urban carrying capacity (UCC) levels is needed as it is “an important barometer and yardstick of sustainable urban development”. As follow-up action, at least one city, which is the most economically dynamic and institutionally innovative region in Sri Lanka, must be taken as a sample to evaluate  the UCC levels and dynamic effects of that urban space.