[ December Thematic Report] Environmental problems in modern cities: Can they be solved?by Valentina Urbasova | 31-12-2023 11:08 |
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 Today, more than half of the world's population lives in cities. By 2050, according to the UN, two-thirds of humanity will live in cities. Meanwhile, all cities in the world occupy less than 2% of the Earth's surface. City dwellers consume much more food, household goods, and natural resources than rural residents. Thus, megacities make a significant contribution to air, water, and soil pollution, and exacerbate the waste problem. In addition, the expansion of urban areas reduces the area of agricultural land and harms biodiversity, leading to changes in natural zones. UN experts call human activity the main cause of global warming. "The city, being a point of high concentration of people, disrupts the processes that have developed in nature. Given current urbanization trends, human impact will only grow," admits urban planner and urbanist Grigory Solomin. Climate change and the consequences of environmental problems Densely populated residential areas, industrial enterprises, and road networks create a huge burden on the environment, exacerbating urban environmental problems. According to the UN, cities consume 78% of the world's energy and are the source of more than 60% of all greenhouse gas emissions. Modern cities are heat islands, where the air temperature is higher than in the surrounding areas. The phenomenon is explained by the fact that large settlements are densely built up, they have a large accumulation of vehicles, asphalted and waterproof surfaces, such as roads, parking lots, dark roofs, can absorb solar radiation, releasing a large amount of heat afterwards. In addition, tall buildings block air flows, which prevents the city from cooling down. Due to the lack of space for the construction of new buildings, green spaces and water bodies are often reduced in megacities, although it is vegetation and water that cool the air. In 2019, American and Chinese scientists came to the conclusion that by the middle of the 21st century, the heat island effect will enhance the effect of climate change in many megacities of the world. So, an increase in air temperature by 2¡ÆC means for a city a warming of 3-4¡ÆC. Deterioration of air quality Polluted air is the main threat to human health, according to the World Health Organization (WHO). According to scientists, 80% of residents of megacities breathe polluted air, and 7 million people die from this every year. According to the IQAir ranking of cities by air quality, the most polluted city in the world in 2020 was Hotan, China. It is followed by 13 Indian cities, including Delhi. In the Russian Federation, the dirtiest air is in Kamensk-Shakhtinsky in the Rostov Region, Krasnoyarsk, Magnitogorsk, Tolyatti, and Moscow. In the ranking of countries with the most polluted air, Russia in 2020 ranked 86th (Bangladesh, Pakistan, and India lead). Impact on water resources The rapid growth of the urban population requires the construction of housing and infrastructure, and accelerates industrial development. According to experts, the need of cities for water has increased tenfold over the past 100 years, and in large megacities such as Paris, Rome, Moscow, Berlin, and New York, by more than 100 times. For the needs of cities, the course of rivers and streams is changed using collectors, dams, and artificial reservoirs. This disrupts the regime of surface and groundwater exchange and can lead to the drying up or disappearance of reservoirs. In addition, their pollution and disappearance are facilitated by the discharge of untreated wastewater and waste disposal. According to hydrologists, in Russia, the Volga is experiencing the greatest load: more than 35% of all untreated wastewater in the country is discharged into its basin annually. Violations in water management and disregard for sanitary norms create risks to human health. According to WHO data, contaminated water can be a source of diseases such as dysentery, typhoid fever, hepatitis A, diarrhea, cholera, and polio. Every year, only from diarrhea caused by the consumption of untreated drinking water, 485 thousand people die in the world. Soil problems Another environmental problem facing cities is soil degradation. Urbanized areas are littered with waste, polluted with chemicals and radioactive substances. In addition, concrete and asphalt pavements prevent water and air from penetrating the soil, which has a negative impact on soil quality. The Food and Agriculture Organization of the United Nations (FAO) found that most of the pollutants enter urban soils from waste accumulation and traffic. Experts warn that substances such as lead, chromium, cadmium, arsenic, or organochlorine pesticides pose a risk to human health. The European Environment Agency believes that waste, both municipal and industrial, is the cause of more than one-third of soil pollution. According to the World Bank, the amount of waste on the planet is expected to increase by 70% by 2050 due to population growth and urbanization. Changes in ecosystems Deterioration of water, air, and soil quality, reduction of green spaces, noise pollution, rising temperatures, and other factors lead to the degradation of the habitat of many plant and animal species. Some of them are unable to adapt to city life. An increase in the area of urbanized areas by 10% could lead to the loss of 80% of local species. Scientists warn that urbanization will cause the greatest damage to regions that are home to many endemic freshwater fish. How to solve environmental problems in large cities Urbanist Grigory Solomin believes that megacities can address environmental problems through planning, administrative, and digital solutions. Planning measures: * Minimization of the heat island effect: planting trees, designing green roofs, reducing the area of concrete and open surfaces; * Improving energy efficiency and energy conservation in buildings and infrastructure; * Rational use of urban land, reducing construction on sites allocated for communications and infrastructure. Administrative measures: * Organizing waste separation and sorting; * Involving recycled materials into circulation; * Using alternative energy sources. Digital measures: * Smart city technologies, including sensors that regulate the supply of heat, water, and electricity in residential buildings, control urban lighting, and signal the need for garbage collection. These measures can help to reduce the negative impact of cities on the environment and improve the quality of life for residents. Sources: https://www.nature.com/articles/s41893-019-0436-6#author-information https://www.who.int/ru https://www.fao.org/home/ru Photo:CHUTTERSNAP / Unsplash
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