Our changing climate is an urban health emergency

Last summer, people in London sweltered through a heatwave that kept indoor temperatures above 30 degrees well into the night. On the other side of the Atlantic, New Yorkers woke to an orange sky as wildfire smoke from Canada blotted out the sun. As I write now, air pollution is drifting across Europe as wildfires, caused by 40-degree heat, rage throughout the continent.

These are different hazards across continents that all point to one thing: the climate crisis is making urban areas increasingly dangerous places to live. And it’s hitting the most marginalised communities hardest.

The evidence is overwhelming. In fact, it’s worth considering that climate deniers have shifted tactics as it becomes harder to deny the obvious changes in the weather. Now, instead of denying the crisis, they are focused on delaying action.

Heat, air pollution, and food

In January this year, the Copernicus Climate Change Service confirmed that 2024 was the warmest year on record, about 1.6 °C warmer than in the late 1800s before large-scale fossil fuel use began driving the climate crisis. Scientists warn that single years could soon reach almost 1.9 °C of warming, pushing us close to dangerous thresholds for human health and ecosystems, including lethal levels in many parts of the world.

This is not just about feeling hot. At around 35°C, the human body’s ability to cool itself via sweating shuts down, leading to death within hours without artificial cooling.

In cities, the urban heat island effect can push us to that limit faster. Urban exposure to dangerous heat has tripled since the 1980s. While Nature Medicine found over 61,000 people died during Europe’s 2022 heatwaves, new projections show that without sharper emissions cuts, heat-related deaths in cities will keep rising. Indeed, The Financial Times reported that we can expect 2.3 million additional heat-related deaths across European cities by 2099 under high-emission, low-adaptation scenarios.

Then there’s air pollution from burning fossil fuels. The World Health Organization estimates air pollution causes between 7-8 million premature deaths each year. In the UK, the Royal College of Physicians recently published their report estimating 500 people are killed every week in the UK, and that air pollution costs the UK £27-50 billion each year.

Meanwhile, air pollution in urban areas is, inevitably, exacerbated by wildfires. It’s shocking that, as wildfires caused by increased temperatures burn, Toronto became one of the most polluted cities in the world.

These are numbers that should cause all of us to reflect on the need for urgent action. Tragically, there are people who haven’t even been born yet who will be killed by air pollution caused by burning fossil fuels today.

Meanwhile climate shocks, for example droughts in grain-producing regions or a flood in a port city, can send urban food prices soaring overnight. Time and time again, we see it’s those living on lower incomes who are most affected by climate-driven increases in nutritious food.

A 2025 report by the Autonomy Institute warns that “climate-flation”, food price inflation driven by climate change impacts such as droughts, flooding, and extreme heat, could raise UK food prices by over 34% by 2050, pushing almost one million additional people into poverty. The UK has already experienced produce shortages due to the climate crisis. For example, in early 2023, when a severe drought in Southern Europe caused British supermarkets to ration items.

This risk is particularly acute in urban areas, where people are heavily reliant on imports, making them vulnerable to supply chain shocks.

The impact is not felt evenly. Households on lower incomes across London, for example, already spend a higher proportion of their income on food, leaving little capacity to absorb sudden price spikes. Many of these areas already have limited access to affordable, healthy options. Rising prices caused by climate shocks risk deepening diet-related health inequalities, driving higher rates of obesity, diabetes, and cardiovascular disease. These conditions, in turn, make people more susceptible to other climate-related health threats, such as extreme heat and poor air quality, locking in a cycle of ill-health and inequality.

Urban health inequality driven by climate change

None of these risks fall evenly. Across urban areas in England, it’s people on low-incomes and living in rented accommodation, people from racially minoritised communities, and people in poorly insulated flats who are far more likely to overheat in summer and to lack access to cool, green space.

In low- and middle-income countries, the poorest urban residents are often pushed to live in flood-prone or heat-trapping areas and are most affected by air pollution.

And, whether it’s a heatwave, a flood, or an air-quality emergency, it is the people with the fewest resources who face the greatest danger, and who have the least power to move, adapt, or recover.

There are ways the Government can protect people’s health in the context of a changing climate and prevent anymore unnecessary illness and deaths.

For example, the government must enshrine the right to breathe clean air in law and set legally binding targets aligned with the World Health Organization’s 2021 guidelines. One way of doing this is by passing Ella’s Law, which was recently reintroduced to parliament.

Policymakers must also commit to high quality, targeted retrofitting to ensure homes stay cool in the summer, warm in the winter, and always free from damp and mould. Doing so would reduce fuel poverty, help houses adapt to climate change, and improve health.

It’s in our urban areas where we’re seeing the effects of the climate crisis most starkly, particularly in terms of health inequality. The time to protect people in urban areas is now.