Current Affairs · · GS3 · Environment

GRAP Stage I returns to Delhi, but emergency curbs have limits

The Commission for Air Quality Management has invoked Stage I of the Graded Response Action Plan as Delhi's air worsened. GRAP tightens restrictions step by step as the Air Quality Index rises. A Hindu explainer cites an analysis finding no steady winter improvement over four years, raising questions about relying on emergency curbs.

Event date:

REq1
  1. Note1 / 5

    WHY IN NEWS?

    • The Commission for Air Quality Management (CAQM) has invoked Stage I of GRAP in Delhi-NCR as air quality slipped into the "poor" range.
    • Winter has begun, when pollution usually peaks.
    • A 2026 analysis by the Centre for Research on Energy and Clean Air (CREA), cited by The Hindu, found no consistent improvement in Delhi's winter air over four winters.
    • The explainer asks whether GRAP is enough.
  2. Note2 / 5

    GRAP STAGES

    StageDelhi AQIExample measures
    I – Poor201–300Dust control, waste management, emission checks
    II – Very Poor301–400Tighter controls, more public transport
    III – Severe401–450Construction curbs; restrictions on older BS-III petrol and BS-IV diesel cars
    IV – Severe+Above 450Truck entry curbs and emergency controls

    Measures are cumulative: each stage adds to the ones before.

  3. Note3 / 5

    KEY CONCEPTS

    1. What is GRAP?

    It is an emergency plan of pre-set actions that kick in as air quality worsens. It was first notified in January 2017 after Supreme Court directions.

    1. What is CAQM?

    A statutory body for Delhi-NCR and adjoining areas, set up under a 2021 law. It replaced the Environment Pollution (Prevention and Control) Authority in enforcing GRAP.

    1. Why is winter worse?

    Cold air near the ground gets trapped under warmer air above — a temperature inversion. Low winds and a shallow mixing layer keep pollutants close to the surface.

    1. What is the National Clean Air Programme?

    Launched in 2019, it sets city-level targets to cut particulate pollution year-round, unlike GRAP's emergency approach.

  4. Note4 / 5

    IS GRAP EFFECTIVE?

    This card sets out documented positions. It does not adjudicate between them.

    • Reactive: Curbs start after pollution rises. CREA reports AQI rose after most of the escalations it studied.
    • Caveat: Rising AQI after escalation does not prove GRAP failed; pollution may have been worse without it.
    • Weak enforcement: Inspections and compliance are uneven.
    • Regional problem: Smoke from outside Delhi cannot be stopped by Delhi's curbs alone.
    • Year-round sources: Transport, industry, dust and waste burning continue all year.
    • Weather: Inversions can override control measures for days.
  5. Note5 / 5

    WAY FORWARD

    These are the explainer's suggestions, not adopted policy.

    • Prevent, don't just react: Expand electric public transport and cleaner industrial fuels.
    • Plan by airshed: Coordinate action across Delhi-NCR and neighbouring States.
    • Enforce better with forecasting and inspections.
    • Support farmers with residue-management machinery.
    • Link GRAP to NCAP so emergency and long-term plans work together.
    • Protect health through timely advisories.

Sources

Syllabus

PaperSubjectSub-topic
GS3EnvironmentEnvironmental pollution, conservation, disaster management
GS2PolityStatutory bodies
PrelimsEnvironmentGRAP stages, CAQM, AQI categories, NCAP, temperature inversion

Topics

Agriculture and EnvironmentWorld Map-Based GeographyGovernance

Related previous-year questions

Asked in earlier UPSC Prelims papers on this topic. Answer, then check.

  1. UPSC Prelims 2016 · Environment and Ecology · Pollution

    In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? 1. Carbon dioxide 2. Carbon monoxide 3. Nitrogen dioxide 4. Sulfur dioxide 5. Methane Select the correct answer using the code given below.

    1. 1, 2 and 3 only
    2. 2, 3 and 4 only
    3. 1, 4 and 5 only
    4. 1, 2, 3, 4 and 5
    Show answer

    Answer: B. VERDICT: The answer is 2, 3 and 4 only. Carbon monoxide, nitrogen dioxide and sulphur dioxide are counted in the Air Quality Index; carbon dioxide and methane are not. ANALYSIS: The National Air Quality Index considers eight pollutants for which short term national ambient air quality standards are prescribed, namely PM10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia and lead. Statements 2, 3 and 4 are therefore CORRECT. Statements 1 and 5 are INCORRECT. Carbon dioxide and methane are greenhouse gases affecting the global climate but are not toxic at ambient concentrations, so they are not local air quality pollutants and do not enter the index. SOURCE: Press Information Bureau material on the National Air Quality Index and press commentary on urban air pollution. Source type EN. HOW TO CRACK IT: This is a fundamental concept fused with a news hook, so keep the two categories of atmospheric problem strictly apart. Air quality is about substances harmful to human health at the point of exposure, while climate change is about gases that trap heat globally. Carbon dioxide and methane belong to the second list and never to the first. Sorting any gas into health hazard or heat trapper before answering resolves this entire question family.

    Difficulty: medium · statement

    Open this question on its own page, with the full explanation →

  2. UPSC Prelims 2022 · Environment and Ecology · Pollution

    In the context of WHO Air Quality Guidelines, consider the following statements: 1. The 24-hour mean of PM 2.5 should not exceed 15 µg/m3 and annual mean of PM2.5 should not exceed 5 µg/m3. 2. In a year, the highest levels of ozone pollution occur during the periods of inclement weather. 3. PM10 can penetrate the lung barrier and enter the bloodstream. 4. Excessive ozone in the air can trigger asthma. Which of the statements given above are correct?

    1. 1, 3 and 4
    2. 1 and 4 only
    3. 2, 3 and 4
    4. 1 and 2 only
    Show answer

    Answer: B. Statement 1 – CORRECT: According to WHO guidelines, the annual average for PM2.5 should not exceed 5 micrograms per cubic metre of air, while the 24-hour average should not exceed 15 micrograms per cubic metre. Statement 2 – INCORRECT: Ozone at ground level is one of the major constituents of photochemical smog. It is formed by the reaction with sunlight (photochemical reaction) of pollutants such as nitrogen oxides (NOx) from vehicle and industry emissions and VOCs. As a result, the highest levels of ozone pollution occur during periods of SUNNY weather — not inclement weather. Statement 3 – INCORRECT: While particles with a diameter of 10 microns or less (PM10) can penetrate and lodge deep inside the lungs, the even more health-damaging particles are those with a diameter of 2.5 microns or less (PM2.5). PM2.5 — not PM10 — can penetrate the lung barrier and enter the blood system. Statement 4 – CORRECT: Excessive ozone in the air can have a marked effect on human health. It can cause breathing problems, trigger asthma, reduce lung function and cause lung diseases. Correct statements: 1 and 4 → Option (b).

    Difficulty: hard · statement

    Open this question on its own page, with the full explanation →

  3. UPSC Prelims 2025 · Environment and Ecology · Pollution

    Artificial way of causing rainfall to reduce air pollution makes use of

    1. silver iodide and potassium iodide
    2. silver nitrate and potassium iodide
    3. silver iodide and potassium nitrate
    4. silver nitrate and potassium chloride
    Show answer

    Answer: A. Artificial rain (cloud seeding) is commonly done using silver iodide (AgI) and sometimes potassium iodide (KI). These substances act as cloud condensation or ice nuclei, helping water droplets form and precipitate. Silver iodide has a crystal structure similar to that of ice, making it an effective ice-nucleating agent. Potassium iodide can also serve a similar function. They are seeded into clouds to promote rainfall. Correct answer: Option (a) — silver iodide and potassium iodide.

    Difficulty: easy · direct

    Open this question on its own page, with the full explanation →

Practice questions

  1. Under GRAP, Stage III is triggered when Delhi's AQI is in the range:

    1. 201–300
    2. 301–400
    3. 401–450
    4. Above 450
    Show answer

    Answer: C. It is the "Severe" category.

    Difficulty: medium · statement

  2. The Commission for Air Quality Management replaced which body in implementing GRAP?

    1. Central Pollution Control Board
    2. Environment Pollution (Prevention and Control) Authority
    3. National Green Tribunal
    4. Delhi Pollution Control Committee
    Show answer

    Answer: B. CAQM was set up under a 2021 law.

    Difficulty: medium · statement

  3. A temperature inversion worsens winter pollution because:

    1. It increases rainfall
    2. Warm air above traps colder, polluted air near the ground
    3. It speeds up winds
    4. It raises the mixing height
    Show answer

    Answer: B. Pollutants cannot rise and disperse.

    Difficulty: medium · statement

Mains practice

Answer-writing practice on this article. Attempt it first, then open the hints.

  1. GS3 · 150 words

    "Delhi's air needs prevention, not just emergency response." Evaluate GRAP's role and limitations in managing winter pollution.

    Show hints
    1. Graded stages
    2. reactive design, enforcement gaps
    3. regional sources, meteorology
    4. airshed approach
    5. NCAP.