TThe UK is facing its first heat wave of summer, and while many will enjoy the hot weather, it is also a warning of challenges ahead, particularly for those who live and work in our biggest cities.
Long periods of high temperatures are becoming more frequent and intense around the world due to climate change, and we are witnessing how our urban areas are struggling to adapt to the heat.
Our cities are designed for cooler climates, but as temperatures rise and levels of greenhouse gases rise, they must be rebuilt to prevent hot weather threatening lives and livelihoods.
Cities are particularly vulnerable during heat waves due to the urban heat island effect. The dark, man-made surfaces of buildings and streets tend to absorb sunlight and trap heat. As a result, the temperature in urban areas is often several degrees higher than in the surrounding rural areas. The structure of our urban areas makes them susceptible to overheating.
And high temperatures can be deadly, especially for people with underlying health problems such as respiratory disease. Cities can also suffocate because bright sunlight often leads to higher levels of air pollution. Damp offices also make employees less productive and affect the economy.
We can’t settle our cities and rebuild them so they can better adapt to our warm climate, so we need to adjust and adapt them.
While it may seem tempting to rely on air conditioning, doing so will result in a significant increase in your electricity consumption. Hot big cities, even in rich countries like the United States, can suffer from summer blackouts due to electricity loads when homes and offices try to maintain a comfortable room temperature. Installing and operating air conditioning can be very costly for those on low incomes, exacerbating climate inequality between the rich and the poor.
Of course, air conditioners simply transfer heat from inside buildings to the outside, making it even hotter outside. We have to take a different approach.
Instead of desperately removing excess heat from our city buildings, we should prevent the sun’s rays from causing the problem in the first place. Offices and homes need tinted glass, blinds, or shutters to block out sunlight. White roofs should become the norm to reflect the sun’s rays rather than absorb them.
New and modified buildings should be designed to maximize ventilation with natural airflow to keep indoor temperatures low. These are the characteristics of well-designed cities in hot countries that we need to adopt. We need building codes that compel builders to design buildings so they don’t overheat.
Public transportation, especially the subway, must be well ventilated and air-conditioned. The London Underground already encourages commuters to take water with them when traveling on hot days to avoid dehydration, but the heat can also cause mechanical and electrical failures in the network.
Road surfaces must be treated to prevent them from melting, and rails and overhead lines must be made of materials that do not stretch and deform excessively at high temperatures. This past summer, we already saw the havoc that high temperatures are causing in our rail system.
But even people who live or work in cities need to change their behavior to protect themselves from hot and humid weather. Once temperatures exceed 40°C (104°F), healthy and fit people can be put at risk if they put in too much effort. So we have to get used to avoiding direct heat at certain times. More cities should follow the lead of those closest to the equator by banning construction and other heavy work during peak summer days. It is time for the English to leave the mad dogs alone to endure the midday sun.
London already follows many other cities in the “cool spaces” where residents of the capital can relax in the hot weather. It also helps to plant more trees to filter the sun’s rays and prevent the sidewalks from becoming unbearably hot.
With this said, our cities must also develop stronger social support systems that will provide assistance and advice to those most vulnerable to heat, especially the elderly. Nursing homes should be a priority to take measures to prevent overheating.
But most importantly, our cities need integrated heat risk management strategies that bring together multiple stakeholders in the public and private sectors at the national and local levels. They may need to follow in the footsteps of Miami, Phoenix and Athens in appointing chief heat officers to coordinate the response.
We all need to change our attitude towards summer. Yes, they are opportunities to enjoy the hot weather. But unless we adapt to our warm climate, our cities will become increasingly unbearable and perhaps even more cruel.