Pollution Reduction: How Much Have We Achieved?

Air pollution has been a pressing issue since the Industrial Revolution, and while cities like London have made significant improvements, 99% of the world's population still live in areas with dangerously dirty air.

In recent years, there has been a global effort to reduce pollution, with varying degrees of success. For instance, the UK has successfully reduced its air pollution levels from a peak of over 60 micrograms per cubic meter in the 1960s to less than 20. This is due to a combination of stricter regulation, reduced industrial activity, and cleaner technologies.

Other countries, like China, have also seen a sharp decline in pollution since the mid-2010s due to the imposition of harsh new regulations.

However, some regions, like Central Asia and parts of Africa, have seen a rapid decline in air quality due to growing populations, urbanisation, and industrialisation.

Despite these disparities, it is clear that efforts to reduce pollution have had a positive impact in many parts of the world, and further action is needed to address the issue on a global scale.

How much has pollution been reduced since the 1956 Clean Air Act?

The Clean Air Act of 1956 was an Act of the Parliament of the United Kingdom, enacted in response to London's Great Smog of 1952, which killed over 4,000 people. The Act introduced measures to reduce smoke pollution and sulphur dioxide from household fires and emissions of gases, grit, and dust from chimneys and smoke-stacks.

The Clean Air Act of 1970, enacted in the US, represented a major shift in the federal government's role in air pollution control. It authorized comprehensive federal and state regulations to limit emissions from both stationary (industrial) and mobile sources. The Clean Air Act Amendments of 1990 further increased the authority and responsibility of the federal government, targeting acid rain, urban air pollution, toxic air emissions, and ozone depletion.

Since 1970, the Clean Air Act and its amendments have significantly reduced pollution in the US. By 1980, control of industrial emissions had led to a 50% decrease in particulate emissions or a 20% decrease in ambient PM concentrations across the country. Today, the PM2.5 pollution that Americans are exposed to is only 35.1% of what it was in 1970. Reductions in particulate air pollution alone have added 1.4 years to the life expectancy of the average American since 1970.

In Los Angeles, PM2.5 particulate pollution has declined by 57% since 1970, extending life expectancy by 1.5 years. Residents of Cook County, where Chicago is located, have gained 1.6 years on average, while residents of Washington, DC, have gained 3 years of life expectancy. Smaller towns and cities, such as Mobile, Alabama, have also seen significant improvements, with pollution levels down by 84.6%.

Overall, the Clean Air Act and its amendments have played a crucial role in reducing pollution and improving public health and environmental protection in the US.

How much has pollution been reduced in the UK?

The UK has long considered air pollution a significant health issue, and it has been linked to numerous diseases, such as asthma, lung disease, stroke, cancer, and heart disease. It is estimated to cause around 40,000 premature deaths each year, costing the country around £40 billion annually.

Sulphur Dioxide Emissions

Sulphur dioxide emissions across the UK have decreased by 95% since 1970, according to Defra. In Scotland, emissions of nitrogen oxides were at 33% of their 1990 level by 2013.

Nitrogen Dioxide Emissions

In 2021, the average yearly NO2 pollution levels across cities in the UK were 15.8 µg/m3, a 5% increase from 2020 but still the lowest since 1990. NO2 levels dropped by 23% in 2020, likely due to COVID-19 restrictions reducing traffic. Between 1997 and 2021, there was an average yearly decline of 1.3%.

Particulate Matter

The yearly average concentrations of PM10 in urban areas decreased from 36.1 µg/m3 in 1992 to 12.9 µg/m3 in 2021, the lowest ever recorded. For PM2.5, concentrations dropped from 12.4 µg/m3 in 2009 to 7.9 µg/m3 in 2021. There was a significant 20% decrease from 2019 to 2020, but in 2021, concentrations rose by 0.6%.

Action Against Pollution

The UK government has implemented various measures to improve air quality, including introducing low-emission zones, promoting electric vehicles through incentives and discounts, and phasing out the sale of new fossil fuel cars by 2030. Local authorities have also established Air Quality Management Areas (AQMAs) and developed Local Air Quality Action Plans to target areas with poor air quality.

Impact of COVID-19

The early days of the COVID-19 lockdown in 2020 saw a significant decrease in air pollution levels across the UK, coinciding with reduced road traffic.

How much has pollution been reduced in China?

China has made significant strides in reducing pollution, particularly air pollution, over the past decade. From 2013 to 2020, China reduced its air pollution levels by 40%, leading to a notable decrease in smog in its cities. This achievement is even more impressive when compared to the United States, which took three decades to achieve a similar reduction.

One of the key catalysts for this change was the 2008 Beijing Olympics, which prompted swift action from the Chinese government to improve air quality in the city. Temporary measures, such as shutting down power plants and restricting coal-burning, were implemented, along with long-term initiatives like encouraging the use of electric vehicles and converting homes from coal and wood to natural gas and electricity. These efforts not only improved air quality but also extended the life expectancy of citizens by an average of two years.

However, China's battle against pollution is far from over. Even with these improvements, Beijing is still three times more polluted than the most polluted city in the United States, and as of 2017, only 107 out of 338 Chinese cities had reached the World Health Organization's interim standard for air quality.

To build on their progress, China has released successive action plans to tackle air pollution. The 2018-2020 Three-year Action Plan expanded the scope of PM2.5 restrictions to more cities and set targets for reducing emissions of volatile organic compounds and nitrogen oxides. While these plans have helped maintain the momentum, critics argue that the targets could be more ambitious, especially for cities that have already made significant progress.

The COVID-19 pandemic and the resulting lockdowns also played a role in reducing air pollution in China. Satellite data showed an average 48% drop in nitrogen dioxide (NO2) densities over China during the initial lockdown period in 2020. This reduction was about 21% greater than in previous years, highlighting the impact of reduced travel and business activity on air quality.

While China continues to face challenges in reducing pollution, particularly in balancing economic growth with environmental protection, the country's dedication to improving its air quality has yielded notable results. The situation in China is getting better, and the danger of smog is gradually being mitigated.

How much has pollution been reduced in the US?

The United States has made significant progress in reducing pollution, particularly in terms of air quality. Since the implementation of the Clean Air Act in 1970, the country has witnessed a notable decrease in various air pollutants. According to the US Environmental Protection Agency (EPA), between 1970 and 2020, the combined emissions of six common air pollutants (particles, ozone, lead, carbon monoxide, nitrogen dioxide, and sulfur dioxide) dropped by 78%. This improvement in air quality has positively impacted public health, reducing the risks of premature death and other adverse health effects.

One of the major successes has been the reduction of lead in the air. The EPA estimates that between 1980 and 1999, airborne lead concentrations decreased by 94%, primarily due to the phase-out of leaded gasoline. Additionally, from 1980 to 2005, airborne lead concentrations decreased by 98%.

The transportation sector has been a key focus of pollution reduction efforts. New passenger vehicles are now 98-99% cleaner for most tailpipe pollutants compared to the 1960s. This improvement is a result of stricter emissions standards and the development of cleaner technologies. The EPA has also set standards for heavy-duty trucks, buses, and non-road engines, leading to significant reductions in emissions.

While the US has made considerable progress in reducing air pollution, there are still areas with poor air quality. In 2023, approximately 140 million people lived in counties with pollution levels above the primary National Ambient Air Quality Standards. Additionally, the US continues to be a major contributor to global carbon dioxide emissions, although its per capita emissions have been decreasing since the 1970s.

Overall, the US has made substantial progress in reducing pollution, particularly air pollution, through the implementation of various policies, regulations, and technological advancements. However, there is still work to be done to ensure that all Americans have access to clean air and to address the country's contribution to global climate change.

How much has pollution been reduced in India?

India has taken several steps to reduce pollution in the country. In 2019, India declared a "war against pollution" and launched its National Clean Air Programme (NCAP), aiming to reduce particulate pollution. The programme initially targeted a 20-30% reduction in PM2.5 and PM10 concentrations by 2024, focusing on 102 cities with poor air quality. In 2022, the Indian government revised its goal, setting no national target but increasing city-level ambitions. The new goal aims for a 40% reduction in these particulate pollutants relative to 2017 levels for 131 cities by 2025-26.

The World Bank is also introducing tools for airshed management and planning to support state and regional air quality management approaches, facilitating the creation of India's first State-wide Air Quality Action Plans and the Regional Airshed Action Plan for the Indo Gangetic Plains (IGP).

Several Indian cities have seen reductions in PM10 particulates over the last few years, attributed to measures taken to reduce sulphur from diesel fuel and stronger enforcement by local authorities. Sulphur dioxide levels have also decreased in the residential areas of cities like Delhi, Mumbai, Lucknow, and Bhopal, thanks to the introduction of cleaner fuels and the increased use of liquefied natural gas (LNG).

The municipal authorities in Delhi, India's capital, have implemented various measures to tackle pollution, including converting vehicles to cleaner fuel, restricting vehicle use at specific times, banning polluting industrial fuel, prohibiting highly polluting vehicles from entering the city, and closing some power stations. The national government has also opened two major periphery roads to divert heavy goods traffic away from Delhi and introduced new fuel emissions standards.

According to the Centre for Science and Environment (CSE), the average levels of PM2.5, one of the worst pollutants, were 25% lower during 2016-2018 than during 2012-2014. The CSE also noted that during the same period, the daily peak levels of PM2.5 decreased, the number of severely polluted days reduced, and the number of days with lower PM2.5 pollution increased.

Despite these improvements, India still has a long way to go in reducing pollution. In 2019, India was ranked as the world's second most polluted country, and 21 out of the 30 most polluted cities in the world were in India. The main contributors to India's particulate air pollution include industrial and vehicular emissions, construction dust and debris, thermal power dependence, waste burning, and the use of wood and dung for cooking and heating by low-income and rural households.

Over 50% of India's air pollution is caused by industrial sources, followed by vehicles (27%), crop burning (17%), and domestic cooking (7%). Fine particulate air pollution (PM2.5) shortens an average Indian's life expectancy by 5.3 years, and in the National Capital Territory of Delhi, the most polluted city in the world, air pollution shortens lives by 11.9 years.

Overall, India's efforts to reduce pollution have shown some positive results, but the country still faces significant challenges in improving air quality and protecting the health of its citizens.

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