Urbanization is the dominant trend in the development of modern civilization. Over the past century, according to UN estimates, the world’s average share of the urban population has grown to 54%. An estimated 3.5 billion people live in urban areas. The urban population is projected to reach 6.3 billion by 2050, raising its share of the world’s population from 50 percent to more than 70 percent. Cities are hubs for creativity and economic progress, but they also face many environmental challenges, driven mainly by hazards related to air pollution, weather, climate and water. Cities are the biggest contributors to climate change that consume 78% of the world’s energy and generate over 60% of greenhouse gas emissions.
In large urban settlements, human activities have a great impact on the state of the environment, creating unique meteorological and climatological characteristics. The accumulation of high-rise buildings, roads, green spaces and concrete surfaces results in challenging patterns of rain, wind, heat and air quality. Hard surfaces can affect water flow rates and exacerbate flood risks. The alignment of buildings in one line can lead to the formation of localized wind tunnels. Traffic and industrial emissions of fine particles can contribute to poor air quality. Local overheating in cities can increase temperatures by 5–10 ° C, exacerbating the effects of heatwaves. The huge population density and the use of fossil fuels make the urban population highly vulnerable to the effects of climate change. The problem is exacerbated by shrinking green spaces.
Types and characteristics of risks in megacities
Currently, the risks of natural and anthropogenic nature are highlighted. Natural risks include natural disasters, hydrometeorological (cyclones, floods, forest fires, hurricanes, typhoons, heavy rains, etc.), geological (earthquakes, landslides, volcanic eruptions, tsunamis, etc.) and biological (epidemic) character. Among the anthropogenic ones, there are environmental, technogenic and socio-economic risks.
The fundamental difference between natural and anthropogenic risk is the following factors. First, natural risks (phenomena) affect all urban systems, the degree of negative impact depends on the strength of the natural phenomenon and the degree of resilience of urban systems to such events. Secondly, these are phenomena of a random, spontaneous nature and their management in the context of the urban environment is limited to monitoring, information support, the organization of special services for the prevention and elimination of the consequences of natural disasters. Thirdly, the significant damage caused by the disaster, as a rule, is estimated at significant amounts of money, and the loss of life can amount to thousands. Fourth, natural risks can provoke anthropogenic risks.
Vulnerability in cities
Urban populations are particularly vulnerable to the adverse effects of air pollution, extreme weather conditions (including heatwaves, floods, droughts and storm surges for coastal residents) and climate change. As urban systems increase in density, complexity, and interdependence, cities can become subject to a domino effect, where one extreme event leads to a general disruption to infrastructure with long-term consequences. It is this interdependence that explains the need for an integrated approach to serving urban dwellers and decision makers in the areas of weather, environment and climate, from weather and climate forecasts to participatory events and urban planning.
The good news is that cities around the world have already begun to take action to reduce greenhouse gas emissions and are pursuing policies to encourage the use of alternative energy sources. However, there is a need to intensify the efforts of policy-makers and leaders to tackle climate change to keep pace with population growth and rapid climate change.
To create smart, sustainable and inclusive cities it is necessary to have historical data and continuous monitoring available. Through easy access to satellite image processing and with the use of analysis and classification algorithms, developed in our R&D laboratories, with Latitudo 40 we are able to provide direct information to improve citizens’ lives, looking at cities from space.