Sustainable Urban Cooling Handbook

The Sustainable Urban Cooling Handbook is a report by the United Nations Environment Program and was released in the month of November 2021. According to the report, the cities around the world will be too hot to live in the future. The Handbook is an encyclopaedia of solutions for sustainable urban cooling.

Key Findings

Cities around the world are twice as hot as the world average. The urban population exposed to high temperatures above 35 degrees Celsius is expected to increase by 800% by the year 2050 compared to the year 2016. It is said that about 1.6 billion urban residents are exposed to this heat. According to the World Health Organization (WHO), the number of people exposed to heat waves increased by 125 million between the years 2000 and 2016. Therefore, if the temperature of the city rises further, it will have catastrophic effects. The International Labor Organization has predicted that a temperature rise of 1.5 degrees Celsius will result in the loss of 80 million full-time jobs by the year 2030. This will result in a global economic loss of $ 2.3 trillion. Low-income countries, especially West Africa and South Asia, will be hit hardest by rising urban temperatures. These areas are said to lose 5% of their working hours due to high temperatures. The report estimates that heat-related deaths will increase to 92,207 in the year 2030 and 255,486 in the year 2050. Power grid failures in extreme weather conditions are increasing. This exposes large numbers of people to severe heat stress as heat waves increase. The energy required to cool the room is expected to triple in the year 2050 compared to the year 2016. This is because millions of new households will install air conditioning systems in the future. Enlarged air-conditioned rooms increase greenhouse gas emissions.

Impacts due to high temperature

The manual describes the possible effects of elevated temperatures. These impacts are predicted based on the ratings of 13 cities in different countries. The effects are Every time the ambient temperature rises, the power demand increases by 3.7%. Room cooling accounts for 30% to 50% of the current peak load. In November 2021, it will be 15% of the peak power load. The largest increase is expected to occur in India. Global demand for room cooling is expected to increase by 300% in the year 2050 as compared to the year 2016.

Identified Issues

Current room cooling systems consume large amounts of energy. They also rely heavily on refrigerant and electricity from fossil fuels. Such systems and practices do not address the problems of urban heat islands and increased emissions, but rather surge in inefficient refrigeration equipment. This will significantly increase emissions in the urban environment. In short, space cooling is a major contributor to the increase in greenhouse gases and the intensification of heat in urban areas. As the use of air conditioning systems increases, additional network infrastructure will be built. This increases the amount of waste heat released to the environment. Socio-economic inequality makes it difficult to calm down. The poor in urban areas are extremely vulnerable to high temperatures.

Solutions to the issues

A consistent set of sustainable urban cooling measures will be implemented. This helps reduce energy demand, improve productivity and health, increase economic benefits and reduce emissions. The report provides three major solutions. They reduce heat on an urban scale, reduce the need for building cooling, and effectively cover the need for building cooling. The manual emphasizes the achievement of human thermal comfort. That is, sustainable cooling is needed. The freezing business has created madness in tropical cities where jackets are comfortably worn inside buildings. You need to change these conditions. The building should be cooled to a comfortable temperature. Therefore, a holistic system approach is needed. This is achieved through energy efficient construction, sustainable use of refrigerants, and efficient cooling technology.