At the turn of the century, according to the United Nations, there were about 300 million people living on the planet, and at the beginning of the modern era, there were about 500 million people. With the use of coal, the world population grew steadily due to technological progress, so that the first billion people were counted around the year 1815. At the beginning of the 20th century there were already two billion people and there are currently 7.4 billion living on earth.
By 1800, 35 million people (three percent of the world's population) populated cities; by 1900, 165 million (ten percent); and by 1950, 740 million (29 percent). Currently, about 54 percent (3.6 billion people) of the world's population live in cities.
According to forecasts, 9.6 billion people will live in 2050, 6.4 billion of them in cities. Two out of three people will then live in urban areas – megacities. By 2030, according to the United Nations, 64 percent in Asia and 56 percent in Africa will live in cities. In 2050, if the trend continues, two-thirds of all people will live in cities and megacities.
The term megacity refers to densely populated urban centers with more than ten million inhabitants. These are far more than simply enormously large cities, they are above all tremendously dynamic and very complex. The ecological, the economic, the social, and the political processes overlap, simultaneously conditioning and reinforcing each other in the process.
The process of disproportionate growth of megacities around the world had begun in the majority of industrialized countries in Europe and North America by the middle of the 20th century. completed by the end of the twentieth century. Today we note the reduction of population in their megacities, except Tokyo. Today, the growth of megacities is taking place in emerging and developing countries. However, there are significant differences between megacities in the developed world and in the developing world – China, India, Indonesia and Nigeria.
In 2015, there were 28 megacities and only two of them were in Europe: Paris and London. By 2030, a total of 41 megacities are expected to exist. The following figures highlight the trend of urbanization: Tokyo including the metropolitan area with 38 million inhabitants, Mumbai with 28 million, Lagos with 24.5 million, Shanghai with 23.5 million, Jakarta with 21.2 million, Sao Paulo with 20.8 million, Beijing with 20 million, Dhaka with 19 million and Mexico City with 19 million.
Urbanization is the key global challenge of the 21st century. The challenges of the twenty-first century. While the growth dynamics of medium-sized cities are already high in many regions of the world, megacities in developing countries harbor a wealth of environmental and health problems as well as enormous conflict potential due to their size. Contemporary megacities are becoming hotspots of social, infrastructural and economic problems of unprecedented proportions.
The United Nations therefore stresses the importance of megacity development keeping pace with population growth. Urgent action is needed in housing, infrastructure, transportation, energy supply, water supply and sanitation, health care and education.
In emerging and developing countries, the urban population is growing exceedingly fast, while the rural population is shrinking. If 3.4 billion people live in villages and small settlements today, this number will decrease to about 3.1 billion in 2050. This urban turn is driven by profound social, economic and psychological factors.
The example of Africa illustrates this: the share of people living in cities in the total population will grow from 37 percent to 53 percent in 2030 – most of them in slums.
People feel rural poverty, severe environmental problems, poor nutrition, land grabbing and lack of water supply – flight to the cities becomes a mantra. However, the rural exodus is leading to the weakening of the centuries-old social structures that have evolved in rural areas, to the fading of traditional environmental knowledge and to insecure land ownership. The inhabitants of the rural areas who are left behind are the ones who suffer from the rural exodus.
The special characteristics of the megacities of the 21. The main challenges of the 21st century are uncontrolled growth and sprawling slums. There is a lack of capital and progressive substance. They lack freedom, political emancipation, economic uplift and social justice. The quality of life for residents in both affluent areas and slums is appallingly low.
Millions of people live in the suburbs, which are "overloaded" with refuse and social conflicts, without adequate access to drinking water, sanitary facilities, education and food. The rich of these countries live in gated, well-policed communities, while the poor masses live in slums with rampant crime. It cannot be emphasized enough in the context of development cooperation that the absence of elementary economic and political foundations for orderly growth continues to fuel the flight to the rich countries of the North.
Another problem that megacities are struggling with is how to dispose of the amount of waste generated. In most cases, neither secure landfills nor adequate incinerators are available, leaving waste in the slums, or in the cities. The wastewater from urban areas enters rivers and the sea through sewers. High population density and uncontrolled land expansion also cause increased erosion.
Major challenges with global implications
Megacities contribute to global climate change, with high levels of air, water and soil pollution due to population concentrations, overburdened infrastructure and inadequate basic services. The high population density in megacities causes the uncontrolled octopus-like land expansion, more and more they "eat" into the surrounding countryside. If food production does not grow in parallel in the surrounding area, distribution conflicts are bound to arise and, most importantly, overuse of water will prove to be the sword of Damocles.
For the urban planners, sociologists, geographers, architects and engineers, there are enormous problems for which a multidimensional solution must be sought. How then should future cities and especially megacities be designed and built to ensure a sufficient quality of life for their residents. On what energies should the supply be based and how should the water and sewage disposal function? Where will all the jobs come from and how will the millions of people be transported?
However, the high internal densification and external interconnectedness of cities also create opportunities for innovation strategies and the promotion of sustainable economies and lifestyles that not only improve living conditions but also develop a spillover effect on surrounding regions. Megacities are therefore the key elements of global sustainable development, both in emerging and developing countries, as well as in developed countries.
Making megacity development more sustainable, therefore, means seeking long-term peacekeeping. The current urbanization and the socio-economic changes that accompany it should not become a mortgage but an opportunity for future generations.
The commitment of all people on the planet is called for here, and Immanuel Kant's statement, "If justice perishes, there is no longer any value in human beings living on earth." I can only agree.