London's Top Polluting Factories: Who's The Worst Offender?

London has had a long history of air pollution, with the Great Smog of 1952 being a notable event that altered how the world viewed air pollution and led to the implementation of life-saving environmental policies. While London's air pollution has declined due to factors such as economic restructuring and increased environmental regulations, it is still important to identify and address the sources of pollution. One of the main anthropogenic sources of air pollution in London is stationary sources, which include factories, power plants, and refineries. The fashion industry, with its reliance on coal and gas in manufacturing, contributes significantly to emissions and water pollution. Additionally, the energy industry, with its heavy reliance on fossil fuels, is a major contributor to global GHG emissions and air pollution.

London's Great Smog of 1952

The smoke and fog brought London to a near standstill, reducing visibility and even penetrating indoor areas. The smog caused major disruption and resulted in a large number of deaths. Government medical reports in the weeks following the event estimated that up to 4,000 people had died as a direct result of the smog, and 100,000 more were made ill by its effects on the human respiratory tract. More recent research, however, places the number of fatalities much higher, with estimates of between 10,000 and 12,000 deaths.

The seriousness of London's air pollution became undeniable after the events of 1952. In response, the British government passed the Clean Air Act in 1956, which established smoke-free areas and restricted the burning of coal in domestic fires and industrial furnaces. Homeowners were also offered grants to switch to alternative heating sources, such as oil, natural gas, and electricity. While change was gradual, and another smog crisis occurred in 1962, the Clean Air Act is considered a major event in the history of environmentalism, and it helped to improve public health in Britain.

The Great Smog of 1952 was not the first time that London had experienced polluted fog. As early as the 13th century, the burning of coal contributed to fog and pollution in the city. The expansion of London and the onset of industrialization in the 19th century worsened these conditions, and the city became known for its dense, yellow fogs, or "pea-soupers". Despite the deterioration of public health, little was done to address the smog due to the economic benefits provided by new industries and the comforts of domestic coal fires.

Coal-burning factories

The industrial revolution, which was powered by coal, further exacerbated the issue. Coal-burning steam engines revolutionized manufacturing, allowing factories to grow in size and locate anywhere, independent of water sources. As a result, numerous small coal-fired power plants sprang up across the UK, including the Duke Street Station in Norwich, which opened in 1893.

The negative impact of coal burning on the environment became increasingly evident in the 1950s, with the occurrence of the Great Smog of London in 1952. This lethal smog, caused by a combination of industrial pollution and high-pressure weather conditions, brought the city to a standstill and resulted in thousands of deaths. The British government responded to this crisis by passing the Clean Air Act in 1956, which restricted coal burning in domestic fires and industrial furnaces and established smoke-free areas.

The transition away from coal has been a gradual process. The UK's last coal-fired power plant, Ratcliffe-on-Soar in Nottinghamshire, closed in September 2024, marking the end of a 142-year era of burning coal for electricity generation. This closure is significant as the UK was the first to harness coal power and is now among the first to quit it, demonstrating a commitment to addressing climate change and improving air quality.

Fossil fuels and carbon emissions

London has long struggled with air pollution, with the burning of coal being the dominant contributor to the city's historic air pollution. The rapidly increasing industrialisation of the late 1700s and the expansion of the coal industry in the 18th and 19th centuries led to a significant increase in national coal consumption. This resulted in London becoming known as the "Big Smoke" due to its polluted fog, which was caused by the combination of industrial pollution and high-pressure weather conditions.

The Clean Air Act was passed in 1956 as a direct response to the lethal fog of the Great Smog of London in 1952, which brought the city to a near standstill and resulted in as many as 12,000 deaths. The Act established smoke-free areas, restricted coal burning, and incentivised homeowners to switch to alternative heating sources. Despite this, another smog crisis occurred a decade later in 1962, highlighting the ongoing challenges of reducing air pollution.

Today, fossil fuels continue to be a significant contributor to carbon emissions, with a small group of major fossil fuel producers significantly increasing production and emissions. According to the Carbon Majors report, half of the world's climate-heating carbon emissions come from the fossil fuels produced by just 36 companies. These companies, including Saudi Aramco, ExxonMobil, Shell, Chevron, and numerous Chinese firms, produced coal, oil, and gas responsible for over 20 billion tonnes of CO2 emissions in 2023.

The manufacturing sector also plays a role in carbon emissions, both directly and indirectly. The production of goods emits carbon dioxide and other greenhouse gases through the burning of fossil fuels and certain industrial processes. Additionally, the manufacturing sector indirectly contributes to emissions when using electricity generated from fossil fuels. Policies addressing emissions in the manufacturing sector can have a positive impact on both direct and indirect emissions.

To summarise, London's air pollution has historically been linked to coal burning and industrialisation, with the Clean Air Act helping to improve the situation. Today, fossil fuel companies and the manufacturing sector continue to be major contributors to carbon emissions, highlighting the urgent need for a transition to renewable energy sources.

Energy consumption

In London, the historical reliance on coal has been a dominant contributor to the city's air pollution. During the 18th and 19th centuries, the coal industry in Great Britain experienced rapid expansion, driven by economic growth, an expanding labour force, and improved distribution networks. As coal prices decreased, national coal consumption increased significantly, exacerbating air pollution.

London's air pollution reached a critical point during the Great Smog of 1952, when the city was engulfed in a lethal black haze for five days, leading to thousands of deaths. This event brought about a shift in how London and the world viewed air pollution, prompting the British government to pass the Clean Air Act in 1956. The Act established smoke-free areas, restricted coal burning, and encouraged the adoption of alternative heating sources.

Today, energy consumption remains a significant contributor to pollution in London. Buildings using electricity and heating, particularly those relying on fossil fuels, contribute to global greenhouse gas emissions. Additionally, refrigeration in supermarkets and retail businesses is a major energy-intensive operation, often powered by fossil fuels.

To mitigate the environmental impact of energy consumption, many businesses and organisations are transitioning to more sustainable practices. This includes the installation of energy-efficient refrigeration systems, the utilisation of renewable energy sources, and the adoption of energy-efficient products. These efforts contribute to reducing energy consumption and, consequently, the pollution caused by this critical sector.

Water pollution

London has a long history of water pollution, with the Great Stink of 1858 caused by the city's failing sewerage system. While London's sewerage infrastructure has improved since then, water pollution remains an issue.

Industrial activities are a major contributor to water pollution in London and worldwide. Factories often discharge wastewater, chemicals, and other waste materials into water sources, including rivers and oceans. This can include toxic substances such as heavy metals, nitrogen, phosphorus, and oil. High levels of nitrogen and phosphorus from crop fertilizers and animal waste can cause excessive aquatic plant growth, leading to eutrophication and hypoxia in water bodies.

Specific types of factories known to cause water pollution include fertilizer plants, pulp and paper mills, textile mills, sugar mills, oil refineries, and chemical, electronics, and automobile manufacturers. For example, in 2019, 59 chemical fertilizer plants in the US dumped approximately 90 million pounds of pollution into waterways. These plants primarily produce nitrogen-based fertilizers, which contribute to the growth of harmful algal blooms.

In addition to industrial activities, agriculture is a significant source of water pollution. Agricultural activities can contaminate water sources through the runoff of pesticides, fertilizers, and animal waste. Large-scale animal farms, or factory farms, can also contribute to water pollution by discharging animal waste and antibiotics into water sources.

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