Picture signs show each scene: 🔴 makes smog · 🟢 cuts smog
Earth Notes · Interactive story · Punjab
One winter day over Lahore
Press ▶ to watch, or scroll at your own pace.
6:50 am · early November
The city wakes up under a dirty sky.
I’m Sana. Let’s see where Lahore’s smog comes from, in one winter day.
7:15 am · before the traffic
Dry sweeping and passing wheels throw dust into the air.
A green bike loader carries the sweepings away.
8:30 am · rush hour
Millions of cars, bikes and rickshaws puff out black smoke.
11:00 am
Factories and brick kilns burn coal, wood and rubbish.
2:00 pm
Farmers burn leftover rice straw. The smoke drifts into the city.
3:00 pm · look east
In winter, most of the wind blows from the east, from India, carrying smoke from its burning fields across the border. Lahore adds its own smoke.
How much crosses the border changes from day to day.
3:30 pm
In the sunshine, gases from cars, kilns and farms rise and mix.
Sunlight turns them into ozone and acids.
Ammonia from farms grabs the acids and makes solid specks.
This tiny dust (PM2.5) is the smog we breathe.
Based on a diagram of PM2.5 formation by Hodan. Simplified.
4:30 pm · when the cloud settles
This dust goes deep into our lungs and makes people sick.
😷 Wear a mask, keep windows shut and keep children indoors.
5:40 pm · watch the sky
Scientists call this a temperature inversion.
10:00 pm
No wind. All day’s smoke is now in the air we breathe.
Next morning, 8:00 am
Schools close and doctors say: stay indoors.
Smog comes from all of us, trapped under one lid.
8:15 am · watching the air
This is the EPCCD building, home of Punjab’s Climate Watch Hub.
Before: an open site throws dust into the air.
EPCCD in Action: green sheets, covered sand and bricks, and water sprinkling.
Air checkers and cameras across Punjab watch for smoke all day.
Smog squads on e-bikes ride out to stop smoky vehicles and fires.
The Nation, 27 July 2026; The Express Tribune, 8 September 2026.
8:20 am · looking ahead
Satellites circle the Earth and watch smoke, dust and gases from space.
Together with weather data, computers predict tomorrow’s air for Lahore.
A forecast gives everyone time to act before a bad day.
8:30 am · fighting back
Smog guns blast fine water drops that catch dust and pull it down.
9:00 am · every source, its own fix
An air observatory fires a laser into the sky to see how high the smog goes.
LiDAR vans drive through the city, mapping the smog as they go.
Super seeders sow wheat without burning, and cleaner kilns and electric buses cut the smoke.
Later that winter
No one fix is enough. Together, every winter, we can clear the sky.
This scene is an illustration, not a forecast.
Chapter 1 · Zoom out
Lahore is not alone. It sits at the western end of the Indo-Gangetic Plain, a vast, flat, crowded plain that stretches from Pakistan’s Punjab to Bangladesh. The Himalaya stands like a wall to the north. In winter, still air lets smoke pool over the whole plain.
Schematic map. The land is real; the plain’s outline, the haze and the district shapes are approximate. National boundaries are not shown.
Chapter 2 · Try it
A grain of sand is about 90 micrometres across. A human hair, about 60. The smog particles that harm us most, PM2.5, are 2.5 micrometres or smaller: some 25 to 30 times thinner than a hair. Zoom in.
SPM, suspended particulate matter, means all the particles floating in the air, up to about 100 µm. PM10 and PM2.5 are its smaller, more dangerous parts.
Pick a particle size, then breathe in.
The WHO says daily PM2.5 should stay under 15 µg/m³. On bad winter days Lahore’s air carries many times that.
Chapter 3 · Inside the air
Some PM2.5 comes straight out of exhausts and chimneys: that is primary. Much of the rest is secondary: gases from traffic, coal and farms react in the air and become particles. Switch on each ingredient and watch.
Adapted from a diagram of PM2.5 formation by Hodan. Simplified: real chemistry has many more steps.
Was each one emitted directly, or formed in the air?
Chapter 4
On a sunny afternoon the ground is warm, so smoke rises high and spreads out. On a still winter night the ground cools, a warm layer sits on top, and smoke is trapped low. Move the clock and watch the chimney.
Chapter 5 · The clean-air lab
On a bad winter day Lahore’s air holds about 300 µg/m³ of PM2.5. Turn the dials and watch what happens to the city.
An illustrative model, not a forecast. Baseline: winter PM2.5 in Lahore about 300 µg/m³ (COMSATS study, 2022 data). Shares: PAQI 2025. Biggest cuts assumed: electric transport 85%, zig-zag kilns 70%, factory filters 50%, no burning and dust control 40%, trees 5%. Wind and season effects are rough illustrations: stronger wind spreads smoke out, and summer’s deep mixing layer plus monsoon rain cut it to about a third. Smog guns clear the air only around the trucks, so the city figure does not change.
Chapter 6
Smog is worst from late October to mid-January. Tap a month to see why the air changes through the year.
Chapter 7 · Try it
Your phone shows a number every morning. Drag the needle and see what each level means for the sky, and for you.
Levels and advice: Punjab AQI dashboard (aqi.punjab.gov.pk), 7 levels. Colours chosen for this story.
Chapter 8
Tap each card to see how it works.
In Kahna, Lahore, the AQI fell from 666 to 170 after the first operation (October 2025). The effect is local and short-lived: cutting emissions matters most.
A year later, the worst days were less bad
Lahore’s daily PM2.5 peaks in November 2025 were 56% lower than in November 2024.
Source: PAQI monitoring, cited by EPD Punjab.
Chapter 9 · Your turn
Clean air is teamwork. Pick the habits you’ll keep this winter, and your shield grows.
Quick quiz
The next morning, after the wind
Smog isn’t made in a day, and it won’t be cleared in one.
What to remember
Every clean kiln, every e-bus and every field left unburnt makes a difference. The sky over Lahore can look like this more often.