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GLOBAL MEGACITIES AND LOW CARBON: FROM CONCEPT PLANNING TO INTEGRATED MODELLING

Phil Jones, Simon Lannon, Robbert van Nouhuys, Hendrik Rosenthal Mega cities

In 1950, 30% of the world’s population lived in cities. In 2000, it was 47%. By 2010 more than half of the world’s population will be living in cities. The total may even reach 60% by 2030 and possibly 85% by the middle of this century. Such rapidly increasing urbanization, particularly in developing countries, creates many opportunities and challenges.

We are living in a globalized and changing world whereby increasingly we require wise use of human and natural resources. At the same time, we need to reduce the risk urbanization poses and enhance the quality of life for all those who live in, or are impacted by Megacities. Megacities are more than just large cities with populations of 10 million inhabitants or more. They are critical to national economies. Their scale creates new dynamics, new complexity and new simultaneity of events and processes – physical, social and economic. They host highly efficient economic activities utilizing intense and complex interactions between different demographic, social, political, economic and ecological processes.

Nations undergoing economic progress often generate rapid urbanization linked with considerable opportunities, as well as strong pressures for change accompanied by environmental degradation. In current times in the developing world, Megacities grow faster than ever before and much faster than their infrastructure can support. Traditionally this results in uncontrolled urban sprawl, high traffic volumes and congested transport systems, high concentrations of industrial production, ecological overload, unregulated and disparate land and property markets, insufficient housing development, excessive waste generation, loss of productivity, general economic constipation, degradation and decline.

Over the past decades traditional Megacities have been suffering from inadequate representative governance, inhibiting spatial planning, building control, delivery of services (such as water supply, sewage disposal and energy distribution), and the establishment of general order (including security and disaster prevention). Existing administrations and their organizational structures may have been outgrown by the rapidly expanding city and may simply be unable to cope with the huge scale of their new responsibilities. On the other hand, megacities contain a rich mix of coexisting people and support systems when properly planned and managed. Groups with their own distinctive ethnic, community, cultural roots, lifestyles and social surroundings have opportunity to thrive and develop. Differences in economic development, social polarization, quality of infrastructure and governance are recognized and taken into

account. The scale and dynamism of Megacities, coupled with complex interacting processes and the sheer concentration of human capital make them incubators of huge growth and innovation. Megacities are the focal points of globalization as well as the driving forces for development; they harbor a wide spectrum of human skill and potential, creativity, social interaction and cultural diversity.

For Hanoi to develop within a rapid urbanization scenario it must look far ahead – not 20 years, not 50 years but 100 years – into the 22nd Century. The use of conventional planning and economic development guidelines have proven to be outdated, resulting in the risk of harboring pronounced poverty, social inequality, and aggravating rapid environmental degradation. Population density, if not managed, increases vulnerability to natural and man-made hazards. Thus, Megacities are both victims and producers of risk, if unmanaged and exposed to the global environmental, socio-economic and political changes to which they contribute.

Megacities will be essential and efficient drivers of a nation’s gross domestic product, processes and activities. Megacities will be ideal places to drive activities and innovation to solve social, environmental, medical, socio-economic and political issues. For these reasons, Megacities are necessary and have potential to substantially contribute towards global justice and peace – and thereby prosperity.

Low Carbon and Energy Modeling

Aspects of sustainable master planning that impact carbon and energy implications need to be understood to help inform concepts at the earliest stage of the design process. For example, the full benefits of reducing operating energy demand of buildings can only be realized if the energy supply can respond to the reduced demand, which includes the additional benefits of reducing the energy supply infrastructure, which in turn reduces its embodied energy. Likewise, if a low (or zero) carbon energy supply is to be used, for example, renewable energy, this is easier to achieve if first the energy demand is reduced. Also, as the operating energy performance of buildings is improved the carbon dioxide emissions associated with the operation of the building, for heating, cooling, lighting, etc., becomes of the same order as the embodied energy used in construction and fit-out of the building and its infra-structure. So a balanced approach across energy demand and supply infrastructure, operating energy and embodied energy, is needed to achieve optimum performance.

This paper describes how the aspects of low carbon planning and design (i.e. operating energy use, embodied energy associated with buildings, energy supply infrastructures, and other infrastructures such as transport, waste, water, sewage, etc.) can be assessed using urban scale modeling, namely EEP-Urban, at a whole city and building plot level. In particular, it explores how the reduction in energy supply infrastructure together with reduced energy demand can lead to reductions in carbon dioxide emissions associated with both operating and embodied energy. The concept of the Megacity in the context of Hanoi in 2110 is used to illustrate the model.

The Concept of Metabolic Super Clusters

Hanoi in 2110 will feature super tall skyscrapers, elevated connectors and railways, nodal communication networks, as well as electrical and energy corridors. Vertical neighborhoods, where people live, shop, relax and work, are built on and above this surface. Built structures are not just individual towers standing independent from another but instead are interlinked and inter-dependent to form an urban spatial organization that allows for vertical connectivity.

The urban model proposes 1 million people on a 1 square kilometer floor plate, hence called a Super Cluster. Under current suburban density standards a similar population would require in the order of 100 square kilometers. Thus, this vision for Hanoi in 2110 saves 99% of land for other uses, most notably conservation of ecological functions and provides food, leisure, material and energy support systems for the city thereby localizing the ecological footprint of the city.

Another distinct aspect of Hanoi in 2110 is that it does not have static building functions. Instead, land use layers, building envelopes and orientations change over time – hourly, daily, weekly, monthly, yearly – to optimize performance efficiencies, therefore becoming a Metabolic Super Cluster. It is envisaged that Hanoi by the end of this century will consist of 30 metabolic super clusters in addition to its traditional urban city centre.

Concentrated compact development will enhance the quality of life for urban dwellers because all infrastructures, environmentally damaging and other undesirable surface activities are located underground or integrated into the vertical structure, thereby significantly improving the quality of living space at the ground, open-air level. Underground space may also provide a safer environment for some public and commercial activities as well as providing shelter from inclement weather conditions. This may prove to be essential for infrastructure in particular, given the predicted impacts associated with climate change. Elevated multi-level connectors between building clusters are converted into common corridors with public amenities, farms and open space.

Quality of life depends on individual perceptions, attitudes, aspirations and value systems. These differ with age, ethnicity, culture and religion, as well as lifestyles, education and cultural background. An individual’s priorities and attitudes to life depend heavily upon socio-economic background and cultural environment. Historic places, cultural sites or public spaces may give Megacities a certain unique identity, heritage, and authenticity. As a result, such spatial capital contributes to social cohesion and makes people feel at home.

Nevertheless, the general opinion may be that the quality of life for many residents in Megacities would be low – for rich and poor alike. Air, water and soil pollution, water and energy supply shortages, traffic congestion, environmental health problems, limited green spaces, poverty and malnutrition, social security and public safety problems place many burdens and restrictions on people.

The Megacity of the future has adapted to greater diversity in socio-cultural circumstances by including and enhancing the often widespread and dynamic informal activities that enrich such communities. Further development of new visions

and innovative management tools are now urgently needed in order to enhance quality of life and create cohesive communities.

Urban governance and management is one of the key success factors of any global Megacity. As society and aspirations evolve over time, the city has to be designed to adapt to change. Utopian cities built around fixed ideologies have never worked. Megacities need to be versatile in order to adapt.

The main challenges for a Megacity in terms of urban governance are: dealing with the speed of change with intelligent urban infrastructure systems; eradicating social exclusion; and introducing proper forms of urban governance.

Way Forward

Whether or not 1 million people are appropriate for a 1 km2 super cluster remains to be seen. The optimum density for sustainability, land use and quality of life may be less and will vary with global location. The above approach is essential to inform the design of high rise high density Megacities if they are to realize their full potential for providing sustainable healthy zero carbon cities of the future that can co-exist in a sustainable way with their neighboring rural areas.