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Subject: Environment

  • I-FLOWS: Mumbai Flood Management System

    Integrated Flood Warning System for Mumbai (I-FLOWS Mumbai), a state-of-the-art flood warning system has been developed for the city.

    Practice question for mains:

    Q. Urban floods in India are consequences of unplanned urbanization in India. Discuss with references to the frequent annual floods in Mumbai.

    What is IFLOWS-Mumbai?

    • IFLOWS is a monitoring and flood warning system that will be able to relay alerts of possible flood-prone areas anywhere between six to 72 hours in advance.
    • The Ministry of Earth Sciences (MoES) has developed the system with in-house expertise and coordination with the Brihanmumbai Municipal Corporation (BMC).
    • The system can provide all information regarding possible flood-prone areas, likely height the floodwater could attain location-wise problem areas across all 24 wards and calculate the vulnerability and risk of elements exposed to flood.
    • Mumbai is only the second city in the country after Chennai to get this system. Similar systems are being developed for Bengaluru and Kolkata.

    How will it work?

    • The primary source for the system is the amount of rainfall, but with Mumbai being a coastal city, the system also factors in tidal waves and storm tides for its flood assessments.
    • The system has provisions to capture the urban drainage within the city and predict the areas of flooding.
    • The system comprises seven modules- Data Assimilation, Flood, Inundation, Vulnerability, Risk, Dissemination Module and Decision Support System.

    Why was this system needed in Mumbai?

    • Mumbai, the financial capital of India, has been experiencing floods with increased periodicity.
    • Floods, especially the ones in 2005 and 2017, are etched in everyone’s memory.
    • Last year, post-monsoon and unseasonal rainfall as late as October, two tropical cyclones in the Arabian Sea had caught authorities off guard and left a trail of destruction.
    • The flood during 26th July 2005, when the city received a rainfall of 94 cm, a 100 year high in a span of 24 hours had paralyzed the city completely.
    • Urban flooding is common in the city from June to September, resulting in the crippling of traffic, railways and airlines.
    • As preparedness for floods before they occur, the system will help in warning the citizens so that they can be prepared in advance for flooding conditions.

    Benefits

    • IFLOWS-Mumbai will enhance the resilience of the city by providing early warning for flooding, especially during high rainfall events and cyclones.
    • Using this, it will be possible to have an estimate of the flood inundation three days in advance, along with immediate weather updates.
    • The Union Minister said the system was “one of the most advanced” ones and will help the city, which has been experiencing floods with increasing periodicity.
    • The hi-tech system will predict floods before they occur, therefore enabling Mumbaikars to take due precautions in advance.

  • Guidelines for Import of Exotic Species

    The Ministry of Environment Forest and Climate Change (MOEFCC) has issued an advisory saying people importing “exotic live species” will have to make a voluntary disclosure.

    Practice questions for mains:

    Q. What are Zoonotic Diseases? Discuss how the illicit trade in wildlife has resulted in the spread of zoonotic diseases of the scale of the ongoing COVID-19?

    What is the new Advisory?

    • According to the advisory, the phrase “exotic live species” includes “animals named under the Appendices I, II and III of the Convention of International Trade in Endangered Species of Wild Fauna and Flora”.
    • It does not include species from the Schedules of the Wildlife (Protection) Act 1972.
    • This will create a process where all imports will be screened.
    • As of now, the imports are being made through the Director-General of Foreign Trade and State Forest departments are not kept in the loop.
    • For new “exotic live species”, the importer should obtain a no-objection certificate from the Chief Wildlife Warden (CWLW) of the State.
    • For existing species, stocks shall be declared by the owner/ holder (stock, as on 1 January 2020) to the Chief Wildlife Warden (CWLW) of the concerned State or UT.

    Why need such advisory?

    • Many exotic species of birds, reptiles and amphibians are imported into India for commercial purposes.
    • Some of the most sought after exotic species in India are Ball python, Scarlet Macaw, sea turtles, sugar glider (Petaurus breviceps), marmoset and grey African parrots.
    • These imports were happening through the Director-General of Foreign Trade (DGFT), but they were beyond the purview of the forest departments and the chief wildlife wardens weren’t aware of them.
    • Wildlife experts have long been asking for stringent laws and guidelines to document and regulate numbers of exotic species being kept as pets by individuals and breeders in India.

    Significance

    • The move comes as the outbreak of coronavirus (COVID-19) has raised global concern about illegal wildlife trade and zoonotic diseases.
    • Often these species are illegally trafficked into the country to avoid lengthy documentation and scrutiny.

    Issues with guidelines

    • Matters such as the spread of invasive species as well as zoonotic diseases had not been taken care of in the advisory.
    • There is a growing domestic trade in exotic species of wildlife that is unfortunately not listed under the various appendices of CITES (such as sugar gliders, corn snakes).
    • Hence limiting the scope of the latest advisory to only those species covered under CITES drastically limits the scope of the advisory itself.
    • It does not have the force of law and could potentially incentivize illegal trade by offering a long amnesty period.

    Back2Basics: CITES

    • CITES stands for the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
    • It is as an international agreement aimed at ensuring “that international trade in specimens of wild animals and plants does not threaten their survival”.
    • It was drafted after a resolution was adopted at a meeting of the members of the International Union for Conservation of Nature (IUCN) in 1963.
    • It entered into force on July 1, 1975, and now has 183 parties.
    • The Convention is legally binding on the Parties in the sense that they are committed to implementing it; however, it does not take the place of national laws.
    • India is a signatory to and has also ratified CITES convention in 1976.

    CITES Appendices

    • CITES works by subjecting international trade in specimens of selected species to certain controls.
    • All import, export, re-exports and introduction from the sea of species covered by the convention has to be authorized through a licensing system.

    It has three appendices:

    • Appendix I includes species threatened with extinction. Trade-in specimens of these species are permitted only in exceptional circumstances.
    • Appendix II provides a lower level of protection.
    • Appendix III contains species that are protected in at least one country, which has asked other CITES Parties for assistance in controlling trade.

  • Species in news: Indian Gaur

    The first population estimation exercise of the Indian gaur carried out in the Nilgiris Forest Division has revealed that more than an estimated 2,000 Indian gaurs inhabit the entire division.

    Try this question from CSP 2012:

    Q. Which one of the following groups of animals belongs to the category of endangered species?(2012)

    (a) Great Indian Bustard, Musk Deer, Red Panda and Asiatic Wild Ass

    (b) Kashmir Stag, Cheetal, Blue Bull and Great Indian Bustard

    (c) Snow Leopard, Swamp Deer, Rhesus Monkey and Saras (Crane)

    (d) Lion-tailed Macaque, Blue Bull, Hanuman Langur and Cheetal

    Indian Gaur

    • The Indian Gaur also called the Indian bison is one of the largest extant bovines found in India.
    • It is native to South and Southeast Asia and has been listed as Vulnerable on the IUCN Red List since 1986.
    • The global population has been estimated at maximum 21,000 mature individuals by 2016.
    • It declined by more than 70% during the last three generations, and is extinct in Sri Lanka and probably also in Bangladesh.
    • In Malaysia, it is called Seladang and Pyaung in Myanmar. The domesticated form of the gaur is called Gayal (Bos frontalis) or Mithun.
    • They are highly threatened by poaching for trade to supply international markets, but also by opportunistic hunting, and specific hunting for home consumption.

  • Lonar Lake colour changes to pink

    The colour of water in Maharashtra’s Lonar Lake, formed after a meteorite hit the Earth some 50,000 years ago, has changed to glaring.

    Make a note of all saltwater lakes in India. Few of them are Pulicat, Pangong Tso, Chilika, and Sambhar Lakes etc.

    About Lonar Lake

    • Lonar Lake, also known as Lonar crater, is a notified National Geo-heritage Monument, saline (pH of 10.5), Soda Lake, located at Lonar in Buldhana district, Maharashtra.
    • It was created by an asteroid collision with earth impact during the Pleistocene Epoch.
    • It is one of the four known, hyper-velocity, impact craters in basaltic rock anywhere on Earth.
    • It sits inside the Deccan Plateau—a massive plain of volcanic basalt rock created by eruptions some 65 million years ago.
    • Its location in this basalt field suggested to some geologists that it was a volcanic crater.

    Why there’s a color change?

    • The salinity and algae can be responsible for this change.
    • There is no oxygen below one meter of the lake’s water surface.
    • There is an example of a lake in Iran, where water becomes reddish due to increase in salinity.
    • The level of water in the Lonar Lake is currently low as compared to the few past years and there is no rain to pour fresh water in it.
    • The low level of water may lead to increased salinity and change in the behaviour of algae because of atmospheric changes.

  • Challenger Deep: the deepest spot in the ocean

    On June 7, astronaut and oceanographer Kathy Sullivan, who was the first American woman to walk in space in 1984, became the first woman and the fifth person in history to descend to the deepest known spot in the world’s oceans, called the Challenger Deep in the Mariana Trench.

    The ocean relief can be divided into various parts such as Continental Shelf, Continental Slope, Continental Rise or Foot, Deep Ocean basins, Abyssal plains & Abyssal Hills, Oceanic Trenches, Seamounts and Guyots.

    Revise these ocean bottom relief  features from your basic references.

    Also revise India’s Deep Ocean Mission.

    What is Challenger Deep?

    • The Challenger Deep is the deepest known point in the Earth’s seabed hydrosphere (the oceans), with a depth of 10,902 to 10,929 m.
    • The deepest part is called the Challenger Deep, which is located below the surface of the western Pacific Ocean.
    • The first dive at Challenger Deep was made in 1960 by Lieutenant Don Walsh and Swiss scientist Jacques Piccard on a submersible called ‘Trieste’.
    • The British Ship HMS Challenger discovered Challenger Deep between 1872-1876.
    • In 2012, film director James Cameron reached the bottom of the Mariana trench after a descent that lasted 2 hours and 36 minutes.
    • Cameron reached a depth of about 10,908 metres on a dive in his submersible called the ‘Deepsea Challenger’ and became the first to complete a solo submarine dive to this spot.

    Why explore deep oceans?

    • Ocean exploration, however, is not randomly wandering in hopes of finding something new.
    • It is disciplined and organized and includes rigorous observations and documentation of biological, chemical, physical, geological, and archaeological aspects of the ocean.
    • Most of the existing knowledge of the oceans comes from shallower waters, while deeper waters remain relatively unexplored, even as humans are relying more on these areas for food, energy and other resources.
    • Further, finding out more about the deep ocean areas can potentially reveal new sources for medical drugs, food, energy resources and other products.
    • Significantly, information from the deep oceans can also help to predict earthquakes and tsunamis, and help us understand how we are affecting and getting affected by the Earth’s environment.

    What does it take to reach the deep ocean?

    • Vehicles called Human Occupied Vehicles (HOVs) may be used that carry scientists to the deep sea.
    • Alternatively, there are unmanned Remotely Operated Vehicles (ROVs) that are linked to ships using cables and can be steered by scientists remotely.
    • Even so, it is difficult for most private citizens to travel more than 100 feet below the surface of the ocean.
    • Further, technical divers can go as deep as 500 feet or more, but with an array of tanks filled with different gas blends.

    Why is it so difficult to explore deep oceans?

    • Most recreational divers can’t explore more than about 120 feet down due to the amount of air needed to keep lungs pressurized at depth.
    • Such depths could lead to nitrogen narcosis, the intoxication by nitrogen that starts to set in around that depth (most of our atmosphere is nitrogen, not oxygen).
    • Waters at such depths of several kilometres exert tremendous pressure which human bodies cannot sustain.

  • Species in news: Asiatic Lion

    Asiatic lions have now significantly risen in number at an estimated population of 674 in the Gir forest region of Gujarat. Unlike in previous years, this count was estimated not from a Census, but from a population “observation” exercise called Poonam Avlokan.

    Try this question from CSP 2017:

    Q. The term ‘M-STrIPES’ is sometimes seen in the news in the context of

    (a) Captive breeding of Wild Fauna

    (b) Maintenance of Tiger Reserves

    (c) Indigenous Satellite Navigation System

    (d) Security of National Highways

    Asiatic Lion

    • Indian Lion (Panthera Leo Persica) is listed as Endangered and exists as a single population in Gujarat.
    • It is one of five big cat species found in India and Gir National Park and Wildlife Sanctuary is the only habitat for Asiatic lions.
    • Historically, it inhabited much of Western Asia and the Middle East up to northern India.
    • On the IUCN Red List, it is listed under its former scientific name Panthera leo persica as Endangered because of its small population size and area of occupancy.
    • More than two dozen lions died last year in an outbreak of canine distemper virus (CDV) and Babesiosis.

    What is Poonam Avlokan?

    It includes two methods:

    • Block counting method — in which census enumerators remain stationed at water points in a given block and estimate abundance of lions in that block, based on the direct sighting of lions who need to drink water at least once in 24 hours during the summer.
    • Other teams keep moving in their respective territories and make their estimates based on inputs provided by lion trackers and on chance sightings.

    Back2Basics: Lion Census in India

    • The first Lion Census was conducted by the Nawab of Junagadh in 1936; since 1965, the Forest Department has been regularly conducting the Lion Census every five years.
    • The 6th, 8th and 11th Censuses were each delayed by a year, for various reasons.
    • This year it was postponed after the lockdown was announced.

  • Will leaders act on the climate crisis as they did Covid-19?

    In the context of climate change, the rising concentration of carbon dioxide and rising global temperature are inextricably linked with each other. This article elaborates on two interlinked and rising curves-CO2 and temperature. The article is concluded on the positive note that leaders would act on climate change with same urgency as Covid.

    The upward journey of two curves

    • Two interrelated curves began their upward trend two centuries ago with the advent of the industrial age.
    • The first curve was the atmospheric concentration of carbon dioxide or, more generally, all greenhouse gases, GHGs.
    • And the second was the average global temperature curve.

    CO2 concentration at 407 ppm: But did we get here?

    • Actually, the CO2 curve began its upward march about 18,000 years ago when it was a little under 200 parts per million (ppm).
    • And earth was much colder back then.
    • By the time it reached 270 ppm about 11,500 years ago, the warmer conditions accompanying this curve made it possible for the emergence of agriculture.
    • Over the past million years, CO2 levels never exceeded 280-300 ppm.
    • They always went back to 200 ppm before rising again in a cyclical fashion.
    • They remained steady at close to 280 ppm for 10,000 years until, beginning in the mid-19th century.
    • They began to rise again as humans burnt coal and oil to fuel the industrial revolution, and burnt forests to expand agriculture and settlements.
    • From a mere 0.2 billion tonnes of CO2 emissions in 1850, annual emissions increased to 36 billion tonnes by 2018.
    • If all this CO2 had accumulated in the atmosphere, we can say that human life would have been altered beyond recognition.
    • Nature has been rather kind to us so far — about one-half of all CO2 emissions have been sanitised from the atmosphere, equally by growing vegetation on land and by absorption in the oceans.
    • Thus, the levels of CO2 in the atmosphere reached 407 ppm in 2018, a level last experienced by earth some three million years ago.

    Global temperature up by 1 degree Celcius

    •  From 1850 onwards, for over a century, the global temperature showed a slight warming trend.
    • But there was nothing suggestive of anything serious.
    • From 1975 onwards, the temperature graph has shown a distinct, upward trend.
    • By 2015, the globe had heated by a full degree Celsius relative to a hundred years previously.
    • Climate modellers unequivocally project that under the current trends of emissions the globe will heat up by 4˚C by the end of the century.
    • he 2003 European heat wave killed over 70,000 people.
    • The years 2015-19 have globally been the warmest years on record.
    • Leave aside the Amazon fire of 2019, the bush fires of 2019-20 in Australia were unprecedented in their scale and devastation.
    • March 2020 has been the second warmest March on record.

    But climate change is not just about temperature rise

    • Climate change involves not just a change in temperature but every other component of weather, including rainfall, humidity and wind speed.
    • Indirect effects follow, such as a rise in sea levels from melting glaciers.
    • Globally there have been several extreme weather events such as hurricanes, heat waves or droughts.
    • While no single event can be directly attributed to climate change, the collective trends are consistent with climate change predictions.

    Warning for India

    • The Climate Impact Lab at the University of Chicago put out a warning for India last year.
    • It says that if global CO2 emissions continue to gallop at the present rate, average summer temperatures would rise by 4˚C in most States.
    • Extremely hot days (days above 35˚C), which were only five days in 2010, would increase to 15 days by 2050 and to 42 days by 2100 on average across all districts.
    • A more moderate emissions scenario, as a result of countries largely fulfilling their commitments under the Paris Agreement, would keep average global temperature rise below 2˚C compared to pre-industrial levels.

    Let’s look into the financial dimension of tackling climate change

    • The most common excuse is that the world cannot afford to curb GHG emissions for fear of wrecking the economy.
    • An article in Nature in 2019 highlighted the financial dimensions of tackling the looming climate crisis.
    • Apparently, the wealthy nations are spending over $500 billion each year internally on projects aimed at reducing emissions.
    • The Intergovernmental Panel on Climate Change, however, estimates that a sustained annual investment of $2.4 trillion in more efficient energy systems is needed until 2035 in order to keep warming below the more ambitious 1.5˚C relative to pre-industrial levels.
    • To put this in perspective, that is about 2.5% of the global GDP.

    What happened to the $100 billion per year aid to poor countries?

    • Some of the wrangling over money relates to the amounts that the wealthy nations, agreed to pay other countries to cope with climate change.
    • Underlying idea was that these countries have caused most of the GHGs resulting in global warming,
    • At the UN Climate Conference in 2009, the richest nations had pledged to provide $100 billion in aid each year by 2020 to the poorer countries for climate change mitigation and adaptation.
    • In 2017, for which data are available, only $71 billion had been provided.
    • And most of the money was spent on mitigation and less than 20% towards climate adaptation.
    • Such numbers had been challenged prior to the 2015 Paris Summit by many countries, including India.
    • It was challenged because much of the so-called aid provided did not come out of dedicated climate funds but, rather, development funds or simply loans which had to be repaid.
    • It thus seems unlikely that the rich countries will deliver $100 billion in tangible climate finance during 2020.

    Time to act

    • COVID-19 has unwittingly given humanity a brief respite from the climate change curve.
    • Commentators are already talking about a paradigm shift in the structure and functioning of societies once the pandemic subsides.
    • This is also a make-or-break moment for the climate trajectory which has to be flattened within a few years if we are to avoid dangerous climate change.
    • Nature’s kindness is not expected to last beyond a 2˚C rise in temperature as the carbon sequestered into vegetation will be thrown back into the atmosphere.
    • Also remember that earth has already warmed by 1˚C and we really have only another 1˚C as a safety margin or 0.5˚C if we are concerned about island nations.

    Consider the mains question asked by the UPSC in 2017-‘Climate change’ is a global problem. How India will be affected by climate change? How Himalayan and coastal states of India will be affected by climate change?

    Conclusion

    There is no substitute to reducing GHG emissions. Technologists, economists and social scientists must plan for a sustainable planet based on the principles of equity and climate justice within and across nations. It is the responsibility of leaders to alter their mindset and act on the looming climate crisis with the same alacrity they have shown on COVID-19.

  • Permafrost and the hazards of its Thawing

    The principal reason that led to the recent 20,000-tonne oil leak at an Arctic region power plant in Russia that is now being recognised is the sinking of ground surface due to permafrost thaw.

    Try this question from Mains 2017:
    Q. What is Cryosphere? How does the Cryosphere affect global climate?

    What is Permafrost?

    • Permafrost is ground that remains completely frozen at 0 degrees Celsius or below for at least two years.
    • It is defined solely based on temperature and duration.
    • The permanently frozen ground, consisting of soil, sand, and rock held together by ice, is believed to have formed during glacial periods dating several millennia.

    Where are they found?

    • These grounds are known to be below 22 per cent of the land surface on Earth, mostly in polar zones and regions with high mountains.
    • They are spread across 55 per cent of the landmass in Russia and Canada, 85 per cent in the US state of Alaska, and possibly the entirety of Antarctica.
    • In northern Siberia, it forms a layer that is 1,500 m thick; 740 m in northern Alaska.
    • At lower latitudes, permafrost is found at high altitude locations such as the Alps and the Tibetian plateau.

    How climate change is eating away at these grounds?

    • The Earth’s polar and high altitude regions — its principal permafrost reservoirs — are the most threatened by climate change.
    • Arctic regions are warming twice as fast compared to the rest of the planet, its current rate of temperature change being the highest in 2,000 years.
    • In 2016, Arctic permafrost temperatures were 3.5 degrees Celsius higher than at the beginning of the 20th century.
    • A study has shown that every 1 degree Celsius rise in temperature can degrade up to 39 lakh square kilometre due to thawing.
    • This degradation is expected to further aggravate as the climate gets warmer, putting at risk 40 per cent of the world’s permafrost towards the end of the century– causing disastrous effects.

    The threat to infrastructure

    • Thawing permafrost is also ominous for man-made structures overhead.
    • The Russian oil leak occurred recorded temperatures in Siberia at more than 10 degrees Celsius above average, and called them “highly anomalous” for the region where the power plant is located.
    • As temperatures rise, the binding ice in permafrost melts, making the ground unstable and leading to massive potholes, landslides, and floods.
    • The sinking effect causes damage to key infrastructure such as roads, railway lines, buildings, power lines and pipelines.
    • These changes also threaten the survival of indigenous people, as well as Arctic animals.

    A ticking time bomb

    • Beneath its surface, permafrost contains large quantities of organic leftover from thousands of years prior — dead remains of plants, animals, and microorganisms that got frozen before they could rot.
    • It also holds a massive trove of pathogens.
    • When permafrost thaws, microbes start decomposing this carbon matter, releasing greenhouse gases like methane and carbon dioxide.
    • Researchers have estimated that for every 1 degree Celsius rise in temperature, these grounds could release GHGs to the tune of 4-6 years’ of emissions from coal, oil, and natural gas.
    • Along with greenhouse houses, these grounds could also release ancient bacteria and viruses into the atmosphere as they unfreeze.

    Back2Basics
    https://www.civilsdaily.com/news/thawing-of-permafrost/

    Also read:

    Ambarnaya River Oil spill in Russia

  • International Convention for the Prevention of Pollution from Ships (MARPOL)

    The Ministry of Shipping has informed about the steps taken for prevention and control of pollution arising from ships in the sea and in the inland waterways under the MARPOL Convention.

    Aspirants must note the following things:

    1. If the convention is a subsidiary to the United Nations/IMO,

    2. Whether it is Legally binding?

    3. If India is a signatory or not …..

    MARPOL Convention

    • MARPOL is the main international convention aimed at the prevention of pollution from ships caused by operational or accidental causes.
    • The Protocol of 1978 was adopted in response to a number of tanker accidents in 1976–1977.
    • It is one of the most important international marine environmental conventions.
    • It was developed by the IMO with an objective to minimize pollution of the oceans and seas, including dumping, oil and air pollution.
    • The Convention includes regulations aimed at preventing and minimizing pollution from ships – both accidental pollution and that from routine operations – and currently includes six technical Annexes.
    • India is a signatory to MARPOL.
    • It has six annexes (I to VI) and it deals with prevention of (1) Pollution from ships by Oil, (2) Noxious liquid substances, (3) Dangerous goods in packaged form, (4) Sewage, (5) Garbage and (6) Air pollution from ships respectively.

  • Green colour band for BS-VI 4W vehicles

    The Ministry of Road Transport and Highways (MoRTH) has issued an order mandating a coloured strip to identify four-wheeled BSVI vehicle.

    Note important PM levels allowed under BS VI norms. Note how it is different from the earlier BS IV norm.

    Details of the colour band

    • MoRTH has mandated a strip of green colour of 1 cm width on top of the existing sticker carrying details of registration for BS-VI.
    • Vehicles of any fuel type will carry the green strip irrespective of their original stickers i.e. for petrol or CNG which have a light blue colour sticker and a diesel vehicle which is of orange colour.
    • These stickers will now have a green strip of 1 cm on top for BS-VI, as mandated.

    Back2Basics:  Bharat Stage Norms

    Standard Reference Date of Implementation
    Bharat Stage II Euro 2 1 April 2005
    Bharat Stage III Euro 3 1 April 2010
    Bharat Stage IV Euro 4 1 April 2017
    Bharat Stage VI Euro 6 April 2020 with a mandate (proposed)

    Minutes of BS-VI

    • Carmakers would have to put three pieces of equipment — a DPF (diesel particulate filter), an SCR (selective catalytic reduction) system, and an LNT (Lean NOx trap) — to meet stringent BS-VI norms, all at the same time.
    • This is vital to curb both PM (particulate matter) and NOx (nitrogen oxides) emissions as mandated under the BS-VI norms.

    How is BS-VI Different from BS-IV?

    • The major difference between the existing BS-IV and forthcoming BS-VI norms is the presence of sulphur in the fuel.
    • While the BS-IV fuels contain 50 parts per million (ppm) sulphur, the BS-VI grade fuel only has 10 ppm sulphur content.
    • Also, the harmful NOx (nitrogen oxides) from diesel cars can be brought down by nearly 70%.
    • In the petrol cars, they can be reduced by 25%.
    • However, when we talk about air pollution, particulate matter like PM 2.5 and PM 10 are the most harmful components and the BS-VI will bring the cancer-causing particulate matter in diesel cars by a phenomenal 80%.