How London is Preparing for Climate Change

At Bank Junction, in the heart of the City of London, newly planted flowers splash color across a heavily concreted area. But these are no ordinary flowerbeds: they are part of efforts to prepare the historic financial district for the effects of climate change.

Across the Square Mile, the City of London Corporation is implementing environmental measures, from upgrading riverbanks to protect them from rising water levels to replacing British flowers with warmer Mediterranean varieties.

The company plans to invest £68m in climate action between 2020 and 2027. But that’s just a fraction of the total bill that will need to be spent over the coming decades to prepare capital for a future of more extreme weather.

The Thames Estuary 2100 project alone, the UK’s largest flood protection programme, designed to protect communities in London and along the river, is expected to cost £16.2bn when completed in 2100.

But climate experts fear the city’s efforts to tackle global warming will not be enough if London’s poorest neighbourhoods struggle to take the necessary measures, while raising questions about inefficient glass and steel towers, poorly designed for a warming world.

Bob Ward, chair of the London Climate Ready Partnership, a coalition of government, business and community leaders focused on building resilience to extreme weather events, said the Square Mile was “a leader in London” when it came to preparing for climate change.

But, he added: “If the City of London does a good job, but other areas don’t, someone else will suffer even more. It’s right that the City is doing what it can, but… it has to convince [other boroughs] to be equally active in addressing the problem.”

Bank Junction’s flowerbeds are designed with a granular fill material to retain surface water and prevent flooding. Rain from the street drains under one bed, while the other collects water from the pavement. Surface flooding is expected to increase as climate change makes rainfall more intense, with the city’s heavily paved surfaces leaving the area particularly at risk.

Alison Gowman is one of a team of councillors who act as elected officials for the city’s local authority. As one of the world’s leading financial districts, ensuring the Square Mile was prepared for the effects of climate change was crucial, she said.

“We are trying to balance the history of the city with the need to protect it,” he added.

Many cities around the world have begun to consider the challenge of how to adapt to climate change. About $63 billion was spent globally on adaptation in 2021-2022, according to a report by the Climate Policy Initiative and the Global Center on Adaptation, with experts saying this will need to increase rapidly in the years ahead as temperatures rise.

New York, which lacks the same flood protection as London, is starting to build a new coastal protection infrastructure, with an expected $52 billion to protect the city from coastal storms.

Singapore has focused on green spaces, while Tokyo has focused on developing a “robust preparedness system,” with regular disaster drills, “so people know what to do when clouds burst or rivers overflow,” said Mark Watts, executive director of C40, a group focused on urban sustainability.

Climate change has already hit the British capital, with flash floods in 2021 and temperatures of 40°C in 2022.

Emma Howard Boyd, former chairman of the Environment Agency, the public body responsible for environmental protection in the UK, agreed that the city was ahead of its counterparts in the capital, particularly when it came to its riverside strategy.

“You’re only as good as your weakest link – that’s where you need that whole-of-London collaboration,” he added.

The London Climate Resilience Review, commissioned by London Mayor Sadiq Khan, warned this month that the British capital was unprepared for the “disastrous consequences” of climate change, with severe flooding and extreme heat posing a “lethal risk”.

He argued that while “significant climate adaptation and resilience actions” were underway in London, these would not be sufficient to address the projected rise in global temperatures.

The report called for a review of the economics of adaptation and climate resilience, citing the National Audit Office, which said the government was “unable to provide an estimate of how much it spends on managing the risks of drought, high temperatures and heatwaves, surface water flooding and storms.

“Actions are being taken by a wide range of government departments and agencies and no one is collecting this information,” he noted.

One of the Square Mile’s major attractions, its riverside location, is also a key vulnerability. The Thames Barrier, located to the east of the City, and the walled defences along the 2km of riverfrontage of the Square Mile have helped protect the area from flooding.

The Environment Agency will have to make a decision on the barrier’s future by 2040, while the walled defences are expected to protect the district for the next 25 years, said Tim Munday, the company’s head of environmental resilience.

But Munday, who went out with his tape measure to examine the walls, said they would need to be repaired in the years ahead and in some places raised by 50cm by 2050 and 100cm by 2100.

Developers of new buildings along the river are being asked to build these defences now or ensure they can be easily built in the coming years, while owners of existing buildings along the Thames are being approached about upgrading the walls.

In some cases, the city will also be raised alongside flood defences, with ground levels raised to ensure that the new, higher walls do not obstruct views of the Thames.

Doing this work will be particularly challenging in areas like Queenhithe, the world’s only surviving Anglo-Saxon pier and an endangered monument. This is where the balance between the city’s history and the impact of climate change will converge, Gowman said.

Elsewhere, Whittington Garden, named aVsceker former Lord Mayor of London Dick Whittington, has been transformed from “a more formal garden” to one designed “on the basis that it doesn’t need a lot of water,” Gowman said. It features thyme and lamb’s ear, as well as other Mediterranean plants.

On Paul’s Walk along the riverfront, the corporation has opted for “ultra-Mediterranean planting,” he added, as he toured the city. “It’s not a beautiful English garden,” he said, but it’s practical.

“Green corridors” have also been introduced, where plants and trees are used to create cooler walking paths. This planting is part of efforts to address the urban heat island effect, where a built-up area is significantly warmer than its surroundings. In some cases, the planting has reduced air temperatures between 3 and 8 degrees Celsius during heatwaves, the company said.

The local authority has also installed 20 sensors across the city to measure temperature, pressure and humidity, in order to understand the different “microclimates” present in the Square Mile area.

One morning in June, a sensor at Walbrook Wharf was almost 1C colder than the one at Holborn Circus. It is also installing sensors to measure soil moisture and water entering sewers.

There is still concern that the city’s buildings, especially new glass and steel construction, are exacerbating the heat’s effects, especially when air conditioning is used to cool the buildings and then pumped out the hot air.

“We need to make sure everything we build is well-adapted to extreme heat,” Ward said, with shutters, less glass and roofs painted white to reflect sunlight.

Ward added that a change in thinking was needed in the construction industry as the City warms up, and an acceptance that London is becoming a warmer place. He added that this would be crucial to avoiding the “shocking mistakes” seen in developments such as the Walkie Talkie building.

Ten years ago, the skyscraper had to be equipped with a sunshade because its concave shape reflected sunlight onto the street below, damaging cars due to the heat.

In a recent planning document, the company said the city could expect 56 days of heatwaves (defined as three or more consecutive days with temperatures of at least 28°C) per year by 2080, up from 14 days in 2020.

He added that the city’s dense, urbanized environment is at risk of extreme heat, saying any new development should “actively” help reduce the heat island effect.

Ward said all of the city’s climate adaptation measures are essential, even if they come with an upfront cost.

“The climate is changing and it will continue to get worse until the world reaches net-zero emissions,” he said.

“But the economic case [for adaptation] “It couldn’t be clearer,” he said. “These are investments to ensure that the city can thrive in the future.”