The heat will become unbearable in cities in the near future if current climate change trends continue.

COP27: Hellish conditions in cities if global temperatures continue to rise

14 November 2022

The article at a glance

As COP27 continues in Egypt, in this blogpost Dean Mauro Guillén looks at the world we may inhabit in 2030 if current trends continue, and writes about what can be done to alter this trajectory.

In the summer months holidaymakers flock to Sharm El-Sheikh for guaranteed sunshine. The eyes of global delegates are currently on rising mercury levels for different reasons. The outlook is dire. Global temperatures are heading towards a rise of 1.5°C, according to the UN’s climate scientists, the Intergovernmental Panel on Climate Change (IPCC). If they reach 1.7 to 1.8°C above 1850s levels, the IPCC estimates that half the world’s population could be exposed to life-threatening heat and humidity.

Why cities will feel the heat the most

Mauro Guillén
Professor Mauro Guillén

As global temperatures rise, urban residents may experience something like hell, a microcosm of what’s to come. Cities occupy just 1% of the world’s land area, yet they are home to 55% of the population and account for 80% of energy consumption. Each week, the population of cities around the world grows by 1.5 million people, which means a new round of construction, pollution, and greenhouse gas emissions.

Cities disproportionately contribute to global warming with their closely packed buildings and surfaces paved with asphalt and concrete, which trap more heat – a process known as “heat island effect”. They also face recurrent water shortages. One out of 4 urban residents, or 1 billion people, don’t have access to piped water in their home. Excessive mortalities and hospital admissions are predicted in urban areas by experts as the world gets hotter.

Cities will also be hit hard by rising sea levels. About 90% of urban areas are coastal, and crudely put, will drown first. Asia is home to 60% of the world’s population and its megacities will be very vulnerable to flooding; Jakarta, Manila, Ho Chi Minh City, Bangkok, Osaka, Dhaka and Shanghai. Outside of Asia, New Orleans, Miami, Venice and Alexandria will be threatened.

The reality is that as large cities grow larger, our problems will continue to multiply: everything from traffic congestion to air pollution, waste disposal to poverty and inequality. Cities are ground zero in the fight against global warming and the widening wealth gap.

Using lateral thinking to find solutions

We can’t afford to feel overwhelmed by those mounting problems. Charles Dickens once said that “the most important thing to be successful is to stop saying “I wish” and start saying “I will”.

Small, ordinary adjustments to our daily behaviour can actually go a long way in averting catastrophe. Avoiding unnecessary waste in food and clothes might cut global emissions by as much as 10%. After oil, those are 2 industries that contribute most to climate change.

Pro-environmental behaviours such as choosing a less polluting transportation mode, participating in recycling programmes, or using environmentally friendly detergents proliferate when people feel a moral obligation to do something about climate change.

Research also shows that pro-environmental behaviours are largely driven by habit. The gap between intention and action can be bridged by nudging (small, subtle changes) that encourage people to develop positive habits. For example, thermostats should display how much it is costing to warm the room as opposed to what the temperature is.

How nanotechnologies could make us less reliant on non-renewable sources

Innovation is essential to balancing growth with protecting the planet. A key area is the new field of nanotechnology which could vastly reduce our dependence on synthetic fibres made from fossil fuels. The process of making a t-shirt from polyester emits more than twice as much carbon as making it from cotton.

Nanotechnologies involve the manipulation of matter on an atomic, molecular, or supramolecular scale. We’re talking about designing particles as tiny of one-billionth of an inch in size with the goal of arriving as stronger, cheaper, or more environmentally friendly materials. Perhaps the most pervasive application of nanotechnologies will be programable matter – materials endowed with the ability to change their physical properties, such as shape, density, conductivity, or optical properties, in response to signals or sensors. By 2030, we may not have to rearrange our closets seasonally, the same garment might provide us with warmth in the winter and relief from the heat in the summer.

It could also make thermal insulation more efficient, less reliant on non-renewable sources. Programmable matter would even enable an aircraft to change the shape, density of flexibility of its wings, making them more energy-efficient under changing flight conditions. Medical applications include the ability to deliver drugs to cancerous cells with extreme precision. Nanotechnologies could also offer cheap, biodegradable substitutes for plastic to avoid polluting fisheries with tiny, harmful particles, that are damaging to wildlife and hazardous if they enter the food chain.

Environmental, demographic, geopolitical, and technological forces are all in motion, and are inextricably intertwined. How we deal with them will be one of the defining tests of this new world to come.