The impact of urbanization on the environment and ways to mitigate it

Introduction

Urbanization is one of the key phenomena of our time, shaping new social, economic, and environmental realities. More than half of the world's population already lives in cities, and according to UN projections, this share will reach 68% by 2050. Cities have become centers of progress, sources of innovation, and places of attraction for millions of people. But at the same time, it is in cities that the main environmental challenges are concentrated, on which the sustainable development of countries and regions depends.

The history of cities goes back thousands of years: the first large settlements appeared in the Nile Valley and Mesopotamia about 5,000 years ago. At that time, cities served as residences for rulers, religious centers, and fortresses. Today, they have become complex systems that affect the life of the planet as a whole. Whereas urbanization was once seen as a natural stage of progress, today humanity is faced with the question: how can this process be made manageable and environmentally safe?

Contemporary trends in urbanization

The growth rate of cities over the past two centuries has been unprecedented. In 1800, less than 10% of the world's population lived in cities; today, that figure is over 56% (Figure 1). At the same time, only about 1% of the land is occupied by urban settlements and infrastructure, but it is this small percentage that consumes the lion's share of resources and energy.

Figure 1. Population living in urban and rural areas.

Cities are growing not only due to natural population growth, but also due to migration: millions of people move every year in search of work, education, medical care, and a better life. At the same time, rapid growth leads to social and environmental imbalances. One of these is the mismatch between population growth and urban expansion. Between 1975 and 2015, the world's built-up area increased 2.5 times, while the population increased only 1.8 times. (Figure 2). This means that in many regions, urban sprawl is occurring, accompanied by land loss, increased transportation costs, and reduced infrastructure efficiency.

Figure 2. Built-up area compared to population (1975–2015).

The opposite trend can be observed in East Asia, where urban density is four times higher than in countries with vast territories and twice as high as in Europe. However, high density alone does not guarantee sustainability: the form of the city plays a decisive role — the organization of space, transport accessibility, the availability of green areas, and the energy efficiency of infrastructure.

Global environmental consequences of urbanization

Urbanization has a complex impact on the environment. One of the most noticeable consequences is the deterioration of air quality. The growth in the number of cars, industrial enterprises, and domestic energy consumption leads to high emissions of particulate matter, nitrogen oxides, and sulfur. In many megacities, pollution levels consistently exceed safe limits, which directly affects human health and reduces life expectancy. "According to WHO estimates, in 2019, about 68% of premature deaths caused by air pollution were due to ischemic heart disease and stroke, 14% were due to chronic obstructive pulmonary disease, 14% were due to acute lower respiratory infections, and 4% were due to lung cancer."

Pressure on water resources is becoming an equally significant problem. Cities concentrate enormous demand for water and at the same time generate large volumes of wastewater. In regions with limited resources, this leads to water shortages and deterioration in water quality. Polluted wastewater is often discharged into rivers and lakes, threatening ecosystems and undermining food security.

Waste poses another serious challenge. Urban residents generate significantly more waste than rural populations. However, recycling systems remain inadequate in most countries. Most waste ends up in landfills, where it pollutes the soil and groundwater and emits methane, a powerful greenhouse gas. Global municipal solid waste (MSW) generation was estimated at ~2.01 billion tons in 2016 and is projected to grow to ~3.40 billion tons by 2050, with a significant proportion of waste currently unmanaged.

Climate risks are exacerbated by the heat island effect. Modern cities, built up with concrete and asphalt, accumulate solar heat, and temperatures in their centers can be 0.5-4 °C higher during the day and 1-3 °C higher at night compared to the suburbs. (Figure 3). Such temperature differences are particularly pronounced in cities with dense development and limited greenery. This increases energy consumption, worsens air quality, and poses health risks to vulnerable populations. The situation is different near bodies of water: ponds and lakes within city limits maintain an almost constant temperature, as water does not absorb solar energy to the same extent as solid surfaces. Parks, green areas, and open spaces also mitigate overheating by creating local “cool islands.”

Figure 3. Heat island effect.

Finally, urban expansion leads to land use transformation and biodiversity loss. Fertile agricultural land and natural areas are being allocated for development. The loss of such land threatens agriculture in the long term and reduces the sustainability of ecosystems.

Thus, urbanization is not only an economic driver but also a factor of serious environmental pressure that requires comprehensive management.

Urbanization in Uzbekistan

In Uzbekistan, the proportion of the urban population is still below the global average, at around 50–51%. However, it is the quality of urbanization processes that is cause for concern. Large cities such as Tashkent, Samarkand, Bukhara, and Fergana are growing due to rural migration. New neighborhoods and suburban areas often arise spontaneously, without proper planning.

One of the main problems is the spatial “sprawl” of cities. (Figure 4; Figure 5). Instead of densifying and optimizing infrastructure, cities are taking over agricultural land, which leads to a decrease in food production potential. At the same time, the burden on transport is increasing: suburban residents are forced to spend more time and fuel every day traveling to the center.

Figure 4. Agglomeration around Samarkand.

Figure 5. Agglomeration of the Fergana Valley.

Small cities such as Jizzakh, Urgench, and Karshi are developing more slowly and do not serve as economic centers capable of relieving large agglomerations. As a result, migration flows are directed toward the largest cities, where infrastructure is overloaded.

Public transport is not developing fast enough. Car ownership is increasing air pollution, especially in the winter months, when household solid fuel stoves add to transport emissions. At the same time, new neighborhoods are being built without enough parks and squares, which in a hot climate leads to overheating and an increase in the heat island effect.

The lack of sustainable construction standards is another acute problem. Energy-efficient technologies, solar energy, and rainwater harvesting systems are still used only sporadically, while mass construction remains energy-intensive and environmentally unfriendly.

If these trends continue, Uzbekistan will face deteriorating air quality, loss of fertile land, transport collapses, and growing social disparities between the center and the periphery in the coming decades.

International experience and lessons for Uzbekistan

Global practice shows that urbanization scenarios can be diametrically opposed. In Latin America, rapid urban growth without proper control has given rise to huge slums with low living standards and high environmental impact. In Europe, on the other hand, the focus has been on compact cities and the development of public transport. Amsterdam and Copenhagen have become examples of a harmonious combination of dense development, green spaces, and cycling infrastructure.

In Asia, Singapore and Seoul stand out. Strict land use policies, green architecture, the introduction of waste recycling technologies, and traffic flow management have allowed these cities to combine high density with a comfortable environment. These are valuable benchmarks for Uzbekistan: even in conditions of rapid growth, urbanization can be made manageable and sustainable.

Ways to mitigate negative consequences

To minimize environmental risks, urbanization must be based on the principles of sustainable development. Priority areas may include:

• Compact development and smart zoning. Instead of suburban sprawl, densify existing areas and develop mixed-use neighborhoods where housing, work, and services are close together.
• Green infrastructure. Create parks, squares, and green corridors. In Tashkent, it would be advisable to increase the standard for green areas from the current 6 m² per person to the WHO recommendation of 9–12 m².
• Public transport. Development of the metro, express bus lines, and bicycle paths. This will reduce dependence on private vehicles.
• Energy-efficient construction. Introduction of standards for new buildings, use of renewable energy, water conservation and thermal insulation systems.
• Waste management. Development of sorting and recycling, transition to a circular economy with reuse of materials.

Conclusion

Urbanization is an inevitable and multifaceted process. It can be a source of innovation and development, but at the same time it creates serious environmental and social challenges. Uzbekistan, which is currently experiencing rapid urban growth, now faces a choice: either allow chaotic sprawl, which could lead to a loss of resources and a decline in quality of life, or steer urbanization toward sustainability.

The experience of other countries shows that with the right policies, it is possible to create cities that are not only economic centers but also places where people can live comfortably. This requires a comprehensive approach involving cooperation between the state, business, science, and citizens. It is important not to put off decisions until tomorrow: the cities of the future are being shaped today, and the quality of life of future generations depends on them.