Great Smog of London will repeat history in Lahore & Sahiwal


 By Ahmad Jawad

Writer is Chief Visionary Officer of World’s First Smart Thinking Tank ” Beyond The Horizon” and most diverse professional of Pakistan. See writer’s profile at

Great Smog of London in Dec 1952, also called Big Smoke, was most severe air pollution in the history of London. It caused 4000 deaths in 5 days of Smog. Some estimate as 12000. Reason for such Smog was coal plants functioning within city of London producing electricity & providing heating to household.

In Pakistan, we are getting Smog alarms every year in Lahore only to wait for a Big Smog incident like London.

Sahiwal with new coal project of 1200 MW is going to be future destination of London Smog incident.

Reference article, By Abbas Hasan in Pakistan Today, ” Carrying coal to Sahiwal “

Of all the projects initiated by the PML-N government, in terms of its long term effect, the 1200 MW coal fired power station at Sahiwal has to be the most egregious. This project does not make economic sense and will in the long term adversely damage the environment in one of the most fertile area in the country. In addition it will unnecessarily burden the main railway line to transport all the coal from Karachi to Sahiwal, and will be sensitive to any depreciation of the rupee given that it is based on imported.

Coal power plants are among the largest emitters of anthropogenic (man-made) deleterious emissions in the world. In an hour a 1,200 MW coal power plant typically emits over 1,200 kg of Carbon-dioxide gas, 9 kg of Nitrous oxide, 5 kg of Sulphur Oxide, in addition to mercury and lead. Both of these metals enter water bodies and food chain with long term effects. Given that the Lower Bari Doab Canal is flowing right next to the power station, it is fair to assume the deposition from the emission will fall onto the canal and its effect will be felt as far a Khanewal district. Coal emissions and fly ash are responsible for arsenic and lead permeating into groundwater seriously damaging the quality of aquifers which supply drinking and irrigation water

Carbon dioxide is heavier than air. Thus the CO2 tends to sink to the ground and stays there. This in turn impacts the leaves on the plants, according to Carnegie’s Department of Global Ecology, “Plants take CO2 out of the atmosphere but they also have other effects such as changing the amount of evaporation from land surface”.

Plants act as giant air conditioners by giving off water through tiny pores called stomata while in daylight converting carbon dioxide to oxygen, a process called photosynthesis, the water is a byproduct and is released through evapotranspiration cooling the entire area around it. But when carbon dioxide levels are high, the leaf pores shrink, this causes less water to be released diminishing the plants health and its cooling power.

“The warming effects of carbon dioxide as a greenhouse gas have been known for a long time” says Ken Caldeira of Carnegie, but he and fellow scientists also warn about the long term effect of elevated CO2 levels on the plants’ health, in addition by reducing the plants cooling power it would cause significant localised warming even of CO2 was not a greenhouse gas.

The area of influence is still being studies but scientist estimate that a radius of as much as 20 km could be affected, so in case of Sahiwal power station it could affect an area from Okara Cantonment to Sahiwal city, over a period of time the plants in this entire area would be damaged. Other than being extremely fertile, this area is the most significant diary production area in the whole country and hundreds of thousands, livelihood depends on this.

Economically also this plant does not make any sense either, a coal power plant typically burns almost 540 kg of coal/ MWhr. Today the current price of coal in the international market is around $110 / tonne, add the cost of transporting this to Karachi and then up country to Sahiwal and you will end up with a cost of approximately $ 140/ tonne. So the fuel cost per MWhr of a coal based plant is approx. $76/ MWhr or approx. Rs 8/ unit, with a total cost (including capital costs) of around Rs 10.5/ unit. Compare this with the cost for a combined cycle furnace oil based unit such as the one in Kot Addu where fuel cost is around Rs 5.5 / unit (Rs 8/ unit in total), or even the expensive LNG gas fired units where the fuel cost is around Rs 5.6/ unit (Rs 8.1/ unit in total).

So the question is: why is this government, bent on laying waste to one of the most fertile areas in the country to produce power that is 40% more expensive than its imported thermal fuel alternatives?

In India the government intends to install 100,000 MW of solar based power plant, as a result the power tariffs for solar there have slumped and currently in the state of Rajasthan, the solar power tariffs (including capital cost) are being bid at 4 Indian Rupee or 7 Pakistan rupee/ unit. Other tenders included Indian Rupee 4.63 or Pakistan Rupee 7.4/ unit. Solar energy is environmentally friendly, can be priced in Rupees and for countries like Pakistan is the future.

I understand that the coal will be imported from Indonesia, so next time the Prime Minister gets into hot waters with the Supreme Court, don’t be surprised if a defense supplication is received from Indonesia.

Reference article : Great Smog of London

The Great Smog of 1952, sometimes called The Big Smoke, was a severe air-pollution event that affected the British capital of London in December 1952. A period of cold weather, combined with an anticyclone and windless conditions, collected airborne pollutants – mostly arising from the use of coal – to form a thick layer of smog over the city. It lasted from Friday, 5 December to Tuesday, 9 December 1952 and then dispersed quickly when the weather changed.

It caused major disruption by reducing visibility and even penetrating indoor areas, far more severe than previous smog events experienced in the past, called “pea-soupers”. Government medical reports in the following weeks, however, estimated that up until 8 December, 4,000 people had died as a direct result of the smog and 100,000 more were made ill by the smog’s effects on the human respiratory tract. More recent research suggests that the total number of fatalities was considerably greater, about 12,000.

London had suffered from poor air quality since the 1200s, which worsened in the 1600s, but the Great Smog is known to be the worst air-pollution event in the history of the United Kingdom,[6] and the most significant in terms of its effect on environmental research, government regulation, and public awareness of the relationship between air quality and health.[2][4] It led to several changes in practices and regulations, including the Clean Air Act 1956.

Sources of pollution


Battersea Power Station, pictured in 2012

The cold weather preceding and during the Great Smog led Londoners to burn more coal than usual to keep warm. Post-war domestic coal tended to be of a relatively low-grade, sulphurous variety (economic necessity meant that better-quality “hard” coals tended to be exported), which increased the amount of sulphur dioxide in the smoke. There were also numerous coal-fired power stations in the Greater London area, including Fulham, Battersea, Bankside and Kingston upon Thames, all of which added to the pollution. According to the UK’s Met Office, the following pollutants were emitted each day during the smoggy period: 1,000 tonnes of smoke particles, 2,000 tonnes of carbon dioxide, 140 tonnes of hydrochloric acid, 14 tonnes of fluorine compounds, and 370 tonnes of sulphur dioxide which may have been converted to 800 tonnes of sulphuric acid.

Research suggests that additional pollution-prevention systems fitted at Battersea may have worsened the air quality, reducing the output of soot at the cost of increased sulphur dioxide, though this is not certain. Additionally, there was pollution and smoke from vehicle exhaust – particularly from steam locomotives and diesel-fuelled buses, which had replaced the recently abandoned electric tram system – and from other industrial and commercial sources. Prevailing winds had also blown heavily polluted air across the English Channel from industrial areas of Continental Europe.


On 4 December 1952, an anticyclone settled over a windless London, causing a temperature inversion with cold, stagnant air trapped under a layer (or “lid”) of warm air. The resultant fog, mixed with chimney smoke, particulates such as those from vehicle exhausts, and other pollutants such as sulphur dioxide, formed a persistent smog, which blanketed the capital the following day. The presence of tarry particles of soot gave the smog its yellow-black colour, hence the nickname “pea-souper”. The absence of significant wind prevented its dispersal and allowed an unprecedented accumulation of pollutants.


Although London was accustomed to heavy fogs, this one was denser and longer-lasting than any previous fog. Visibility was reduced to a few metres (“It’s like you were blind”) making driving difficult or impossible.

Public transport ceased, apart from the London Underground; and the ambulance service stopped functioning, forcing users to transport themselves to hospital. The smog even seeped indoors, resulting in the cancellation or abandonment of concerts and film screenings as visibility decreased in large enclosed spaces, and stages and screens became harder to see from the seats. Outdoor sports events were also affected.

In the inner London suburbs and away from town centres there was no disturbance by moving traffic to thin out the dense fog in the back streets. The result was that visibility could be down to a metre or so in the daytime. Walking out of doors became a matter of shuffling one’s feet to feel for potential obstacles such as road curbs. This was made even worse at night since each back street lamp at the time was fitted with an incandescent light-bulb, which gave no penetrating light onto the pavement for pedestrians to see their feet, or even the lamp post. Fog-penetrating fluorescent lamps did not become widely available until later on in the 1950s. “Smog masks” were worn by those who were able to purchase them from chemists.

Near railway lines, on which “fog working” was implemented, loud explosions similar to the report of a shotgun were a common feature. The explosions were made by “detonators” – a form of large percussion cap placed on the track and activated by the wheels of trains. These devices were placed by certain signals to provide an audible warning to match the visual indication provided by the signal for the driver.

Health effects 

There was no panic, as London was renowned for its fog. In the weeks that ensued, however, statistics compiled by medical services found that the fog had killed 4,000 people. Most of the victims were very young or elderly, or had pre-existing respiratory problems. In February 1953, Lieutenant-Colonel Lipton suggested in the House of Commons that the fog had caused 6,000 deaths and that 25,000 more people had claimed sickness benefits in London during that period.

Mortality remained elevated for months after the fog. A preliminary report, never finalised, blamed the ongoing deaths on an influenza epidemic.[2] Emerging evidence revealed that only a fraction of the deaths could be from influenza.[16] Most of the deaths were caused by respiratory tract infections, from hypoxia and as a result of mechanical obstruction of the air passages by pus arising from lung infections caused by the smog.[17][18][19] The lung infections were mainly bronchopneumonia or acute purulent bronchitis superimposed upon chronic bronchitis.

More recent research suggests that the number of fatalities was considerably greater than contemporary estimates, at about 12,000.

Environmental impact 

The death toll formed an important impetus to modern environmentalism, and it caused a rethinking of air pollution, as the smog had demonstrated its lethal potential. New regulations were implemented, restricting the use of dirty fuels in industry and banning black smoke.

Environmental legislation since 1952, such as the City of London (Various Powers) Act 1954 and the Clean Air Acts of 1956 and 1968, led to a reduction in air pollution. Financial incentives were offered to householders to replace open coal fires with alternatives (such as installing gas fires), or for those who preferred, to burn coke instead which produces minimal smoke. Central heating (using gas, electricity, oil or permitted solid fuel) was rare in most dwellings at that time, not finding favour until the late 1960s onwards. Despite improvements, insufficient progress had been made to prevent one further smog event approximately ten years later, in early December 1962.

In considering whether such an event could occur again, research has shown relationships between meteorological conditions, ambient atmospheric pollutants and specific mortalities. By comparing English local authority areas aggregated on a geographical scale, a clear relationship emerges between oil combustion effluents and an excessive deaths certified as caused by pneumonia due to a directly toxic acute lung injury, a finding concordant with deaths during the London smog of 1952.


احمد جواد

لندن میں 1952 میں بد ترین فضائی آلودگی کا بڑا مظہردیکھا گیا جس کو عظیم سموگ بھی کہا جاتا ہے۔ پانچ دنوں میں یہ سموگ 4000 افراد کی اموات کا باعث بنا۔ کچھ لوگوں کا اندازہ 12000 اموات تک جا پہنچا۔ سموگ بننے کا باعث لندن شہر میں  گھریلو بجلی اور حرارت فراہم کرنے کے لئے کوئلے سے چلنے والے کارخانے تھے

پاکستان میں ہر سال سموگ کے خطرے کی گھنٹیاں بجنے لگی ہیں اور لندن کی طرح لاہور سموگ کے سانحے کا منتظر ہے۔ لندن  سموگ جیسے المیہ کی  اگلی منزل ساہیوال میں لگایا جانے والا نیا 1200 میگا واٹ کا کول پراجیکٹ ہو گا