GOAL 3 : ENVIRONMENTAL ISSUE : POLLUTION IN MEGACITIES JULIE LABRADOR INTRODUCTION 'Hell’, wrote Shelley, ‘is a city much like London: a populous and a smoky city’. There could be no better illustration of this than a sadly notorious weekend more than sixty years ago. In December 1952, a suffocating shroud of smog settled over London and caused the deaths of more than 4,000 people, thus becoming the world’s worst air pollution disaster. Today, this may seem anachronistic and far from our everyday preoccupations. Yet, a large number of cities, still including London, live under a deadly cloud of invisible pollutants that irreversibly deteriorate ecosystems and cause great concerns for human health. Megacities cover less than 2% of the Earth’s surface and consume more than 75% of its resources. This, along with their uncontrolled growth, has brought along problems and challenges. Their potential importance in tackling climate change can thus no longer be neglected. Pollution constitutes both an environmental and social threat for megacities. Furthermore, because of increasing urbanization, this issue may be exacerbated in the future and thus undeniably needs to be tackled rapidly and efficiently. DEFINITION OF KEY TERMS Megacities A megacity is defined by the United Nations as a metropolitan agglomeration which concentrates more than 10 million inhabitants. However, this definition has been slightly enlarged because the world’s 40 most populated cities (see map below) are now considered megacities even if they do not necessarily have 10 million inhabitants. These 40 cities take part in the association called “C40” which aims to propose common projects and seek innovative alternatives for a sustainable development. These 40 megacities account for more than 18% of global GDP, generate over 10% of global carbon emissions and their total population is around 300 million residents. •
Source: IGU MegaCity -­ TaskForce • Pollution ‘Pollution’ is the introduction into an environment, such as water, air or ground, of toxic substances that damage human health and have a negative impact on ecosystems. Pollution is mostly caused by human activity: discharge of domestic, industrial and agricultural waste, gas emissions into the atmosphere, etc. However, some areas may also be prone to air pollution because of their particular topography or climate. • Air pollution episodes An ‘Air pollution episode’ is a short-­‐term increase in air pollution which is ‘greater than would be normally expected as part of day-­‐to-­‐day variation’, according to Air Pollution and Health by Stephen T. Holgate. • Particulate matter Also known as particle pollution or PM, particulate matter is composed of very small particles and liquid droplets. The danger of these particles for human health lies in their size: particles that are 10 micrometers in diameter or smaller generally enter throats, noses and lungs, thus affecting the latter organs. BACKGROUND INFORMATION According to a UN report from 2010, the world’s population is expected to rise by 2.3 billion people, between 2009 and 2050. In Addition, while only 10% of the population lived in the cities before the Industrial Revolution, today urban dwellers represent 50.5% of the global population. Megacities are thus constantly growing but they are also increasingly polluted: the United Nations Environment Programme (UNEP) notably reported that ‘rapid industrialization and burgeoning cities have caused increasing production of harmful pollutants in most urban cities’.  Air pollution The first and certainly most obvious issue generated by this urbanization is undoubtedly air pollution. The concentration of human activities, such as transport and industry, in a relatively small area puts an enormous pressure on the environment and often leads to environmental problems caused by the emission of dangerous gases. While most countries suffer from their dependency on fossil fuels ; motor traffic, industry, agriculture, trade and domestic activities constitute the main sources of pollution today and result in the deterioration of the quality of ambient air. Among them, an investigation published by Mage (1996) notably reported that motor traffic is the most damaging source of air pollution in megacities. Indeed, along with development of the standard of living in emerging countries comes an increasing number of cars. Their global number has indeed increased by a factor of 10 since 1950 throughout the world, most of which circulate in major cities. Yet, the most harmful pollutant affecting megacities is particulate matter, particularly amongst Air pollution in Beijing Asian megacities. Chinese megacities are known to have high levels of particles. They have reacted to this by creating hundreds of ‘oxygen bars’ where people can purchase a can of clean oxygen. This shows the gravitude of air pollution. The destruction of forests located around cities for settlements and agriculture also contributes to the deterioration of the quality of ambient air, as it greatly limits photosynthesis. However, on top of this constant ambient pollution, the so-­‐called peaks of pollution, also known as air pollution episodes, tend to be even more destructive because of their intensity. They generally come from forest fires or volcanic eruptions and can easily be exacerbated by stagnant weather conditions that impair their dispersal. Mexico City, for instance, suffers due to its high altitude and climate resulting in poor ventilation. The South-­‐East Asian haze is an example of air pollution episodes: in June 2013 Singapore, Malaysia and Indonesia were suffocating in a cloud of historically-­‐
high pollution. However, air pollution episodes are also very often the direct or indirect consequence of a drastic increase in burning fuel for transport, industry or domestic use. An important air pollution episode notably occurred in Beijing no later than 2013. This led to several measures taken by the government that greatly affected the life of the population, such as the necessity for heavy polluting enterprises to reduce emission by 30% and the establishment of a ban on outdoor sports activities for primary and middle schools.  Water pollution Water pollution constitutes another major challenge for megacities. Waste generated by the city dwellers indeed becomes onerous and particularly difficult to manage and most of it is dumped into rivers. Subsequently, water is made unclean and shortages are becoming more and more frequent in certain countries. Everyday, 2 million tons of human waste are disposed in water courses. For example, the Nile river in Cairo (Egypt) is pressured by a growing population and the political and economic demands of modern times (see picture above). The pollution of rivers is made worse by the increasing number of slum dwellers due to their illegal and unplanned nature: many cities are indeed experiencing a massive rural exodus and can no longer cope with the large influx of migrants notably in terms of housing and waste management. Furthermore, waste can also have disastrous effects on the quality of underground soil in cities. It is indeed likely to be polluted due to dangerous chemicals often released by industrial waste. On top of the shortages of clean water for domestic use, the deterioration of water quality also results in huge problems notably concerning the fishing and agricultural sectors. In China, for instance, the Institute of Geographic Sciences and Natural Resources Research reckons that heavy metal pollution in underground soil has so far affected more than 10 percent of the country's farmland and caused the loss of 12 million tons of grain every year.  Consequences of pollution Several studies report that ambient air pollution threatens the health of a large fraction of the world’s population. Short-­‐term and long-­‐term health effects of exposure to air pollution can indeed be observed. In the short-­‐term, high levels of air pollution can lead to acute respiratory problems. In addition, blockage of sunlight may promote the spread of harmful bacteria and viruses that would normally be killed by ultraviolets. The United Nations Environment Programme (UNEP) unit reported that air pollution resulted in the death of over 1 million people in 2012. As an example, 12.6% of deaths in Jakarta are linked to the polluted ambient air. Furthermore, the possible long-­‐term health effects of exposure to air pollution are still unknown and difficult to determine. Components of smoke haze are presumably carcinogens but their effects may not be apparent for years. Moreover, deteriorating urban air, ground and water quality also deeply affects the viability of important natural and agricultural ecosystems both in megacities and in regions surrounding highly urbanized areas. Accelerated urban growth presents an enormous challenge for the preservation of biodiversity in Indian megacities: a transformation of ecosystems from woodlands or grasslands into ‘urban concrete jungles’ often leads to further degradation. A great decrease in native bird species, for instance, has been observed in Delhi and more than 69 species of birds are currently considered as ‘threatened’, according to the Indian Institute of Science. Finally, the economic impact of pollution in megacities can no longer be neglected. In both the developed and the emerging world, the loss in GDP growth due to pollution reaches 2% and 5% respectively. This is due to the health expenses caused by pollution, the necessary slowing in the pace of economic activities in case of air pollution episode, etc. Lyon, for instance, experienced exceptionally high levels of pollution in April 2013 (see picture above) and, in addition to disastrous effects on health, the peak of pollution had multiple economic consequences. In order to reduce the emission of CO2 due to transports, the authorities decided to subsidise the company responsible for public transports and free bus tickets were provided to the population to encourage these to be used. Even costly improvements and measures to reduce air pollution in cities could therefore be made profitable by the potential economic benefits generated on the long-­‐term. Despite these alarming figures, several recent surveys, including CityZen, seem optimistic about the future of megacities in the developed world. Air quality indeed tends to progress in many developed countries. Although the United States is still among the most polluting countries in the world, a strong downward trend in its greenhouse gas emissions has been observed, explained to a large extent by the success in detoxification of power plants and a general decrease of gases emissions from cars. In California, for instance, first stage smog alerts have been reduced from 200 a year in the 1970s to about 10 over the same period of time today. Japan and Europe are also experiencing a continuing downward trend in air pollution. Pollution in the developed world is still a worrying issue. These attempts to preserve the environment therefore need to be pursued and similar projects must be initiated in the developing world. MAJOR COUNTRIES AND ORGANISATIONS INVOLVED Results of the World Health Organisation (WHO) and the UNEP study of megacities show that the ‘most severe air pollution is monitored in cities in developing countries’. Developing countries, experiencing a rapid and massive urbanisation due to the apparent opportunity for a better quality of life in cities, are indeed plagued by the issue of pollution. This challenge is particularly acute, for instance, in China where the deterioration of air quality is becoming a major issue, as shown by a 2006 Chinese Green Gross Domestic Product estimate that reported that pollution in 2004 caused a GDP loss of 3%. Other emerging countries, such as India or Mexico, are currently experiencing the same issue. These high levels of pollution are due to a wide range of factors but three particularly stand out in developing countries: the chaotic manner in which megacities are sprawling, the use of polluting sources of energy and the permissive policy towards polluting companies. However, whilst several studies such as CityZen point out the decrease in pollution in the developed world, the deterioration of the environment in megacities located in post-­‐
industrialised countries is still a major concern. The most polluted megacity in Europe remains London but recent peaks of pollution in Paris, leading to drastic traffic restrictions notably brought to light the latter issue. Despite the relatively low number of megacities in Africa, Cairo and Lagos are today considered as two of the most polluting cities in the world. Lagos, the economic capital of Nigeria concentrating over 70% of the country’s industries, may indeed be one of the three megacities in the world with a population exceeding 20 million by 2025. However, its rapid growth and chaotic urbanization have resulted in an increase in waste generation and environmental pollution. Although the central focus of the United Nations Environment Programme (UNEP) is not megacities, they are largely taken into account in the fight against climate change. UNEP notably created an air quality guideline for a wide range of pollutants which serves as a reference measurement of pollutants. The World Health Organisation (WHO), the first institution that established the link between health problems and pollution, is also particularly concerned about the consequences of pollution for human health. ‘The evidence signals the need for concerted action to clean up the air we all breathe’ Dr. Maria Neiro (WHO) A recent EU-­‐funded project known as the ‘CitiZen project’ aims to ‘quantify and understand current air pollution distribution and development in and around selected megacities, including the interaction across the different spatial scales’. It gathered a wide range of important, but previously disparate, areas of research in order to provide a general picture of the mechanisms by which megacities impact the environment. TIMELINE OF EVENTS -­‐1952: First major air pollution disaster due to the London’s ‘smog’. -­‐1987: Establishment of the Montreal Protocol that aims to decrease the use of chemical compounds destructive to ozone in the stratosphere by 50% by the year 1999. -­‐1992: Establishment of the United Nations Framework Convention on Climate Change (UNFCCC). -­‐2003: London Congestion Charging Scheme. -­‐2005: Kyoto Protocol became effective. -­‐2008-­2011: Cityzen project (Megacity). -­‐2009: Copenhagen summit (United Nations Climate Change Conference). -­‐2012: CNG (Compressed Natural Gas) programme in India. RELEVANT TREATIES AND ORGANISATIONS Although international protocols have not yet been extended to the local scale according to Megacities: Our Global Urban Future by Frauke Kraas, several conventions have been established with the aim of tackling climate change and most of them are thus implicitly related to megacities. The United Nations Framework Convention on Climate Change (UNFCCC) of 1992 constitutes a turning point in the fight against climate change, as it aims to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system". Further discussions at later conferences then led to the Kyoto Protocol which notably required 37 industrialized countries (see map below) to reduce their emissions by an average of 5% below 1990 levels during the period 2008 to 2012. Due to the large proportion of pollution generated by megacities, these goals won’t be reached without drastic measures to reduce the impact of the most urbanized areas on the environment. Source: UNEP
PREVIOUS ATTEMPTS TO SOLVE THE ISSUE The United Nations millenium goals stated that ‘switching to renewable energy sources was crucial’ for the sustainability of megacities. The Kyoto Protocol also greatly encouraged investment in renewable energy. At least 48 countries now have a renewable energy promotion policy, including 14 developing nations. On a local scale, several megacities have already set up measures in order to reduce their emission of harmful pollutants and preserve the environment. London, the most populous but also most polluting city in the European Union, implemented the London Congestion Charging Scheme (CCS) in February 2003 in order to reduce the traffic congestion and the high levels of air pollution they cause. This measure implies a charge of £5 for vehicles entering a central London zone during the busiest hours. A study carried out by Beevers and Carslaw in 2005, notably pointed out the large reduction in distances traveled in vehicles. To meet the demand to travel into central London an increase in the frequency of public transports was also crucial. Finally, a reduction in emissions of CO2 has been observed, providing evidence that a scheme of this kind will assist in attaining government targets relating to climate change. In Delhi various policy measures have been proposed. In view of the seriousness of the health effects of air pollution and to improve the air quality of Delhi, public transport was amended by the Supreme Court of India to implement CNG (Compressed Natural Gas), a less polluting fuel, instead of diesel or petrol to reduce vehicular pollution. The success of this measure then led Tehran, Los Angeles, Bangkok, Santiago, Cairo, Beijing and several other cities to establish a natural gas program. Other cities have initiated different measures with relative success. Ten European cities now have zero-­‐emission buses powered by hydrogen fuel cells. China is also exploring the possibility of substituting renewable energy sources as a mean of lowering its pollution levels and data on water pollution have recently been collected. POSSIBLE SOLUTIONS The necessity for constructed and accurate indicators and metrics for pollution control and natural resources management has been brought to light by the United Nations Millennium Development Goals (MDGs). Indeed, the fight against climate change is still often criticized as being insufficiently defined and inadequately measured. So the creation of new ways of measurements would constitute a large step in the preservation of the environment and the reduction of pollution. As the impact of only two hundreds of pollutants have been investigated so far and the ambient concentrations are determined for an even smaller number resulting in a major limitation for urban air quality management, research is primordial in order to improve our knowledge of these components and be able to eradicate them more efficiently. Using cleaner fossil fuels, such as natural gas, burning these fuels more efficiently and increasing reliance over renewable sources of energy (hydro, solar, geothermal) are some of the best ways to control and reduce air pollution without limiting economic growth. In order to tackle the issue of water pollution, more efficient and affordable water treatments are primordial. Research will thus once again be necessary in order to achieve these goals. BIBLIOGRAPHIE http://www.wmo.int/pages/prog/arep/gaw/documents/GAW_205_DRAFT_13_SEPT.p
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impact-­‐megacities http://www.eoearth.org/view/article/149934/ http://www.who.int/mediacentre/factsheets/fs313/en/ Air Pollution and Health by Stephen T. Holgate, Hillel S. Koren, Jonathan M. Samet, Robert L. Maynard Selahattin Incecik and Ulaş Im (2012). Air Pollution in Megacities: A Case Study of Istanbul, Air Pollution -­‐ Monitoring, Modelling and Health, Dr. Mukesh Khare (Ed.), ISBN: 978-­‐953-­‐51-­‐0424-­‐7, InTech Megacities: Our Global Urban Future by Frauke Kraas, Surinder Aggarwal, Martin Coy, Günter Mertins APPENDICES -­‐Impacts of megacities on air pollution and climate -­‐Pollution in Istanbul (Case study) -­‐CityZen -­‐Pollution in the developing world -­‐Real-­‐time air quality index visual map