London is the ninth largest emitter of CO2 in the world. While the city has come a long way in terms of the quality of its environment since the Great Smog of 1952 – a severe air pollution event that affected London, – toxic air, pollution, and biodiversity loss among others still pose major challenges to its residents. These issues are complex and interconnected and improving them requires time as well as huge political and financial efforts. Here are some of the biggest environmental problems in London and what the city is doing to address them.

Environmental Problems in London

1. Air Pollution

Air pollution is without a doubt among the most pressing environmental problems in London. The city is among the most polluted cities in the United Kingdom. The problem does not only affect central districts but rather the whole city and suburbs. In fact, 100% of its residents live in areas where pollution exceeds the recommendation of the World Health Organization (WHO) of PM2.5 particulate matter – extremely fine particles able to enter deep into the lungs.

Besides energy production, industrial processes, and construction, transportation is a significant contributor to air pollution in the city. The volume of traffic and vehicles on the road is the single largest cause, producing nearly half the nitrogen oxides and emitting rubber and metals into the air. However, road traffic is not the only culprit. A Financial Times investigation on the air quality in the carriages of the London Underground found the levels of pollution to be alarmingly high, making the Tube the most polluted part of the city. The reason behind this is that, over the years, particulate matter of dust and metal has built up in tunnels. These toxic substances are stirred up by trains and inhaled by passengers. 

Inhaling such particles leads to a wide range of harmful health conditions related to heart disease, stroke, lung cancer, and other respiratory infections. Air pollution has also been linked to infertility and infant mortality. This major environmental issue contributes to an average of 9,000 premature deaths every year and costs London’s healthcare system between £1.4 and £3.7 billion (US$1.6 – 4.3 billion) per year. 

The government has taken significant steps to improve the air quality in the city. For example, the Ultra Low Emission Zone (ULEZ) – launched in 2019 and expanded in 2021 to cover a larger area – requires vehicles to meet specific emission standards. If these are not met, owners are subjected to a fee. Since the implementation of ULEZ, harmful pollutants found in the air in London’s central districts have been cut by almost half, with nitrogen oxide alone diminishing by a staggering 44%. Other efforts include operating cleaner public buses and taxis and supporting London residents to switch to cleaner modes of transport. 

2. Waste 

London – the largest city in the UK with a population of more than 9 million – inevitably generates a large amount of waste on a daily basis. Every year, the capital’s residents produce more than 18 million metric tonnes of waste. 9.7 million tonnes of it comes from the construction industry, 5 million tonnes from the commercial industry – which is related to business waste ranging from anything such as wrappers to food waste and cardboard – while over 3.1 million is household waste. 

The UK capital has one of the lowest rates of recycling in the country, with only 32% of all waste being recycled or composted and this makes waste one of the biggest environmental issues in London. This is by far one of the lowest rates as compared to the rest of the country. While some of London’s waste is sent to other parts of the UK and abroad, over half the waste in London is incinerated, the main alternative to landfills. The amount of incinerated waste more than doubled within the last decade. Waste plants do not sort through the waste before incineration, resulting in large amounts of recyclable materials being unnecessarily incinerated. For example, since not all boroughs of the city offer separate food waste collection, food waste, which could be safely sent through environmentally friendly processes, is instead burnt. 

Although burning waste can generate heat and electricity, burning some materials such as plastic creates and releases harmful heavy metals and toxic chemicals such as dioxins, causing long-term health issues. Unburned plastic litters the environment and can be ingested by animals, harming the environment. 

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By 2026, London aims to send no biodegradable waste (including food waste) to landfills and by 2030, the city hopes to recycle 65% of its municipal waste. To achieve this, multiple steps have been taken. Minimum recycling standards for waste authorities have been set, including a requirement for separate food waste collection. Multiple schemes have been implemented to reduce packaging waste such as water refill stations to reduce single-use plastic water bottles, working with stakeholders to reduce unnecessary packaging, and spreading awareness among  Londoners on how they can reduce their own waste.

3. Flooding

London is prone to flooding through five sources – tidal, fluvial (from rivers and tributaries), surface (from rainfall), sewer, and groundwater flooding. Most of London is at risk of flooding due to one or more of these, with the highest risk concentrated around the river Thames. Due to climate change – which would bring about wetter winters and heavier rains that can raise the sea level – both the risk and intensity of major flash floods have increased

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People’s homes and well-being are significantly affected by floods, especially those of people living in basements and inner-city areas with a high population density and little green space. Experts currently estimate that at least 80,000 properties are at risk of surface water flooding. Furthermore, without proper drainage in the city, a lack of green spaces, and an increase in the use of basements, the antiquated sewage infrastructure of the city is under significant strain. 

Since 1982, the Thames barrier and other defences in place have protected the city from tidal flooding. While London is well protected against tidal flooding, it has a much lower level of protection in place against surface-level flooding. To tackle this problem, the government must invest in infrastructure and urban solutions that can increase the city’s resilience to flooding. 

One such solution is to invest in more Sustainable Drainage Systems (SuDS). These include investing in more porous pavements and road surfaces as well as an increased number of parks and green roofs on buildings, which help prevent water from running off quickly into drains or vulnerable areas. 

4. Energy Consumption

Heating makes up 40% of energy consumption in the UK. As stated by the Committee on Climate Change (CCC): “UK homes are not fit for the future”. Not only can many residents not afford to heat their homes, but old and inefficient boilers also have a significant detrimental impact, emitting pollutants into the environment. Boilers burn fuel to generate steam for heating and hot water. Fuel combustion results in toxic air emissions, contributing to air pollution. Furthermore, wastewater is created as waste from non-combustion activities and is released into the water.

While this is a considerable issue throughout the country, refitting and better insulating homes to be more efficient are especially challenging for London. Currently, London is falling behind on its target to make 2.9 million homes more efficient. A quarter of London homes and 37% of non-domestic buildings in the city have been certified E, G, and F, the worst energy ratings, by the Energy Performance Certificate, meaning that an incredibly large amount of energy is wasted every year. Houses and workplace buildings account for 36% and 42% of the city’s CO2 emissions respectively. 

The CCC proposed that by 2025, no new homes should be connected to the gas grid. To meet the target emissions, homes must switch to low-carbon heating. There are multiple ways in which this can be achieved. London wants to introduce more local and decentralised energy sources, with the mayor wanting the city-wide deployment of air-source heat pumps, a low-carbon heating system that runs on electricity and draws warmth from the environment, by 2030. However, gas contributes to 30% of London’s total emissions mostly to heat buildings, and without decarbonising gas networks and switching to greener gases such as hydrogen, London is unlikely to achieve net-zero emissions.

5. Biodiversity Loss

Biodiversity loss is also among the most pressing environmental problems in London. While it may seem unlikely, London has a rich flora and fauna, something rare in other parts of the UK. The identification of over 1,500 Sites of Importance for Nature Conservation (SINCs) – covering 19% of Greater London – is “a recognition that the capital’s ecological assets are much more widespread and are critical to the functioning of the city” – said Mathew Frith, director of the London Wildlife Trust Conservation, in an interview.

However, due to climate change and rising temperatures that are making habitats increasingly inhabitable, these populations are under threat. In addition to that, population growth is another big threat. By 2050, London is predicted to house 11.1 million people and this population and economic growth will pose major challenges to the city’s environment and habitats. 

In May 2018, the mayor of London released the London Environment Strategy which details four strategic methods to ensure London’s biodiversity is able to thrive:

1. Low carbon circular economy

A low carbon circular economy is one in which resources are efficiently used by maximising reusing and recycling before turning them into waste. As London grows, it must invest in low-carbon infrastructure and services. For example, by manufacturing goods that are made to last rather than be disposed of and by creating a system that allows goods to be reused and recycled.

2. Smart digital city

Smart technologies can help address environmental challenges, making environmental systems such as energy, water, and waste, more efficient. For example, smart energy metres can help reduce energy use and smart heat networks can increase efficiency in heat production.

3. Green infrastructure

Green infrastructure can help reduce the impact of climate change and store carbon. Promoting healthier life habits, such as reducing car dependency and encouraging more cycling, will also improve biodiversity and ecological resilience, as well as air and water quality.

4. Healthy streets approach

The healthy streets approach provides a framework for putting the human experience at the heart of city planning. Environmental factors have a big impact on the way people interact with it. Improving the environment against healthy street indicators would ensure streets are inclusive and sustainable, helping create a better city.

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