It is in the cities that the social, economic and environmental dimensions of sustainable development converge more intensively, making them necessary to be thought, managed and planned according to the sustainable development model which aims to meet the current needs of the Earth's population without compromising its natural resources, bequeathing them to future generations.

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HOW TO MAKE SUSTAINABLE CITIES
Fernando Alcoforado *
The city has become the main habitat of humanity. For the first time in human history,
more than half the population is living in cities. This number, 3.3 billion people, is
expected to exceed the 5 billion mark by 2030. At the beginning of the 20th century, the
urban population did not exceed 220 million people. Access to jobs, services, public
facilities and greater economic and social well-being is her greatest attractive to all who
go to it. Most of the global environmental problems originate in the cities, which makes
it difficult to reach sustainability at the global level without making them sustainable
[BEAUJEU-GARNIER, J. Geografia Urbana (Urban Geography). Lisboa: Fundação
Calouste Gulbenkian, 1980].
The process of urbanization occurred in a significant way first in the countries of the
European continent, with the emergence and development of industries during the
eighteenth century. Since 1950, this process has taken on a large scale on a global scale.
The process of industrialization has expanded in many countries, attracting more and
more people to the cities. However, urbanization without proper planning results in
several environmental and social problems. The swelling of the cities, caused by the
accumulation of people, and the lack of an adequate infrastructure generates
inconveniences for the urban population. Most cities around the world grow in a
disorderly, chaotic way.
The uncontrolled growth of cities around the world often underscores the lack of urban
planning, generating irreversible impacts on these territories, which are reflected in their
environmental quality. Significant impacts on the environment occur due to the modes
of production and consumption in the urbanized spaces. Pollutions, traffic jams,
violence, unemployment, etc., are common in cities. Water pollution is mainly caused
by the release of untreated industrial and domestic effluents. Air pollution is a major
problem detected in cities that is due to the release of toxic gases into the atmosphere.
The intense flow of cars and industries are primarily responsible for this type of
pollution.
Other environmental problems resulting from urbanization are: waterproofing of the
soil, visual pollution, noise pollution, climate change, acid rain, absence of
environmental sanitation, lack of adequate disposal and treatment of solid waste,
greenhouse effect, among others. The lack of effective urban planning compromises the
quality of life of the urban population. The disorderly growth of cities generates the
occupation of places unsuitable for housing by low-income populations, such as high
slope areas, valley bottoms, among others.
The accelerated urbanization and growth of cities, especially from the middle of the
twentieth century, have promoted physiognomic changes on the planet, more than any
other human activity. The population of Brazil, for example, presents the same global
tendency of environmental occupation, that is, it opts for the urban ecosystem as a
home. The transformation of Brazil from rural to urban occurred in the 1960s following
a predatory process in essence, with marked social exclusion of less privileged classes
that, because they did not have the conditions to acquire land in structured urban areas,
occupy mostly land which should be protected for the preservation of waters, slopes,
valle bottoms, among others.

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In Brazil, data presented by the Brazilian Institute of Geography and Statistics (IBGE,
2004) indicate that more than 80% of the people are urban dwellers and should reach
85% in the next twenty years. This growth of urban centers has led to a sharp fall in the
quality of life and to a growth of social problems and environmental imbalances,
aggravated by recent structural changes in capitalist dynamics. This fact makes it a
requirement to work with the principles of sustainability incorporated into urban
management, focusing on issues such as reducing poverty levels; creation of jobs;
implementation of sanitation, education and health systems; adequacy of urban land
use; pollution control; environmental recovery; use of clean energy sources; combating
urban violence; protection of historical and environmental heritage, among others.
It is in the cities that the social, economic and environmental dimensions of sustainable
development converge more intensively, making them necessary to be thought,
managed and planned according to the sustainable development model which aims to
meet the current needs of the Earth's population without compromising its natural
resources, bequeathing them to future generations. It means that the model of
sustainable development in the cities must be adopted aiming at the compatibility of
economic and social factors with the environment. What characterizes a sustainable
city? It is the right of the population to urban land, housing, environmental sanitation,
urban infrastructure, transportation and public services, work and leisure for current and
future generations.
Sustainable cities are cities that have a policy of economic and social development
compatible with the natural and built environment. Sustainable cities have as a guideline
the planning and control of land use, in order to avoid the degradation of natural
resources. A sustainable city must have clear and comprehensive policies for sanitation,
garbage collection and treatment; management of water, with collection, treatment,
economy and reuse; transport systems that favor the transport of masses with quality
and safety; actions that preserve and expand green areas and use of clean and renewable
energies; and, above all, transparent and shared public administration with organized
civil society.
In the contemporary era, when global warming problems can lead to catastrophic
climate change on a planetary scale, every city has to have a climate change adaptation
plan, especially those subject to extreme events. Coastal cities, for example, must have
planning against the predictable rise of the level of the oceans and worry about
landslides on slopes, floods, etc. resulting from inclement rainfall. In short, they must
have flexibility and adaptability to the new climatic requirements. It is necessary to
redesign the urban growth of the cities in order to integrate it with the natural
environment, to recover its beaches and its rivers now very committed with the launch
of sewers, so that the city does not receive a hostile response of the natural environment.
Arcadis, a Dutch project consulting, engineering and management company that
emerged in Amsterdam in 1868, launched the 2015 Sustainable Cities Index, ranking
the 50 most sustainable cities in the world. The index was calculated by the Center for
Economics and Business Research considering the social (people), environmental
(planet) and economic (profit) factors that make a city sustainable. In the top positions
of the ranking are well-developed European cities such as Frankfurt, followed by
London, Copenhagen, Amsterdam and Rotterdam. The cities of Seoul, Hong Kong and
Singapore also appear prominently, closing the Top 10 with Berlin and Madrid
[ARCADIS, As cidades mais sustentáveis do mundo (The most sustainable cities in the

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world). Available on the <http://www.cidadessustentaveis.org.br/noticias/cidades-mais-
sustentaveis-do-mundo>].
As for the social factor (people), a deep analysis was carried out on the quality of life of
citizens, whose indicators alternate between the health and life expectancy of the
population of the city, as well as the level of literacy of the people, the cost of living
average income and rates of crime and social inequality. As for the environmental
factors (planet), an analysis was made of the green factors (electric energy consumption,
quantity and quality of public parks, amount of emission of greenhouse gases in the
atmosphere, production of energy from renewable sources such as solar energy,
exposure to natural disasters, and water and air quality). As for the economic factors,
the economic health analysis was carried out, evaluating the cities' GDP (Gross
Domestic Product), their employability rate, general infrastructure and transportation,
tourism and business care. These are the indicators based on which one can assess the
social, environmental and economic sustainability of cities.
* Fernando Alcoforado, 77, member of the Bahian Academy of Education and the Brazilian Academy of
Letters of Rotary - Bahia Section, engineer and doctor in Territorial Planning and Regional Development
by the University of Barcelona, university professor and consultant in the areas of strategic planning,
business planning, regional planning and planning of energy systems, is the author of the books
Globalização (Editora Nobel, São Paulo, 1997), De Collor a FHC (Editora Nobel, São Paulo, 1998), Um
Projeto para o Brasil (Editora Nobel, São Paulo, 2000), Os Condicionantes de Desenvolvimento do
Estado da Bahia (PhD Thesis, University of Barcelona, http: //www.tesisenred.net/handle/10803/1944,
2003), Globalização e Desenvolvimento (Editora Nobel, São Paulo, 2006), Bahia- Desenvolvimento da
Bahia do Século XVI ao Século XX e Objetivos Estratégicos na Era Contemporânea (EGBA, Salvador,
2008), The Necessary Conditions of the Economic and Social Development- The Case of the State of
Bahia (VDM Verlag Dr. Müller Aktiengesellschaft & Co. KG, Saarbrücken, Germany, 2010),
Aquecimento Global e Catástrofe Planetária (Viena- Editora e Gráfica, Santa Cruz do Rio Pardo, São
Paulo, 2010), Amazônia Sustentável- Para o progresso do Brasil e combate ao aquecimento global
(Viena- Editora e Gráfica, Santa Cruz do Rio Pardo, São Paulo, 2011), Os Fatores Condicionantes do
Desenvolvimento Econômico e Social (Editora CRV, Curitiba, 2012), Energia no Mundo e no Brasil-
Energia e Mudança Climática Catastrófica no Século XXI (Editora CRV, Curitiba, 2015), As Grandes
Revoluções Científicas, Econômicas e Sociais que Mudaram o Mundo (Editora CRV, Curitiba, 2016) e A
Invenção de um novo Brasil (Editora CRV, Curitiba, 2017). Possui blog na Internet
(http://fernando.alcoforado.zip.net). E-mail: falcoforado@uol.com.br.