Compare
Two places. What can each learn?
Line up documented issues, causes, impacts and solutions. TerraLens does not rank places or produce an overall score — context differs, and so do the right answers.
Delhi
India · 2 documented issues
A vast northern Indian capital region where winter air pollution, water stress and extreme heat affect tens of millions of people.
London
United Kingdom · 2 documented issues
A tidal-river capital that pioneered clean air law after the 1952 smog, now managing traffic pollution and long-term Thames flood risk.
Categories
| Category | Delhi | London |
|---|---|---|
| AirShared | Severity: Critical | Severity: Moderate |
| WaterShared | Severity: High | Severity: Moderate |
“Not documented” means the atlas has no write-up for that category there — not that the place is free of it. Severity is descriptive editorial metadata summarising documented effects. It is not a measured index or a score.
Environmental issues
Available indicators
Only indicators backed by a source are shown. Figures from different places are not directly comparable.
Delhi
- WHO annual PM2.5 guideline
- 5 µg/m³ · 2021
- Emergency framework
- Graded Response Action Plan
- Assessment category
- Over-exploited units
London
- Policy milestone
- London-wide ULEZ · 2023
Causes
Delhi
Delhi's winter air pollution
- Winter meteorology over the Indo-Gangetic Plain
- Crop residue burning in neighbouring states
- Transport emissions
- Construction and road dust
- Industry, waste burning and domestic fuel
Groundwater depletion in the Delhi region
- Extraction exceeding recharge
- Sealed recharge surfaces
- Gaps in piped supply
London
Traffic pollution and the Ultra Low Emission Zone in London
- Diesel vehicles
- Congestion
- Wood burning and other sources
Tidal flood risk on the Thames
- North Sea storm surges
- Sea level rise
- Land subsidence in south-east England
Impacts
Delhi
Delhi's winter air pollution
- Severe health burden
- School closures and restricted activity
- Economic cost
- Reduced visibility
Groundwater depletion in the Delhi region
- Falling water tables
- Water quality deterioration
- Reduced drought resilience
London
Traffic pollution and the Ultra Low Emission Zone in London
- Health effects
- Inequality
Tidal flood risk on the Thames
- Risk to people and property
- Rising maintenance and upgrade costs
Solutions
Delhi
Delhi's winter air pollution
- Graded Response Action Plan
- Crop residue management
- Fuel and vehicle standards
- Dust control on construction and roads
- Airshed-level governance
Groundwater depletion in the Delhi region
- Managed aquifer recharge
- Metering and extraction regulation
- Reliable piped supply and leak reduction
London
Traffic pollution and the Ultra Low Emission Zone in London
- Ultra Low Emission Zone
- Cleaner buses and taxis
- Walking and cycling investment
Tidal flood risk on the Thames
- Thames Barrier
- Thames Estuary 2100
- Riverside defence raising
Learning across locations
Both places are dealing with air, water and air pollution.
These documented approaches from one place address a shared category or theme in the other. Whether they transfer depends on local climate, governance, resources and the specific causes involved. Themes are matched from the wording of each issue.
AirFrom Delhi relevant to London
Graded Response Action Plan
A staged set of emergency measures triggered automatically as air quality deteriorates.
Context: Delhi's winter air pollutionAirFrom Delhi relevant to London
Crop residue management
Machinery, incentives and alternative uses to avoid burning stubble in neighbouring states.
Context: Delhi's winter air pollutionWaterFrom Delhi relevant to London
Managed aquifer recharge
Engineered recharge structures, restored water bodies and rainwater harvesting.
Context: Groundwater depletion in the Delhi regionWaterFrom Delhi relevant to London
Metering and extraction regulation
Licensing and monitoring of borewells, particularly for commercial users.
Context: Groundwater depletion in the Delhi regionAirFrom London relevant to Delhi
Ultra Low Emission Zone
A daily charge for vehicles not meeting emissions standards.
Context: Traffic pollution and the Ultra Low Emission Zone in LondonAirFrom London relevant to Delhi
Cleaner buses and taxis
Zero-emission buses and cleaner taxi requirements.
Context: Traffic pollution and the Ultra Low Emission Zone in LondonWaterFrom London relevant to Delhi
Thames Barrier
A movable barrier that closes during high surge tides.
Context: Tidal flood risk on the ThamesWaterFrom London relevant to Delhi
Thames Estuary 2100
An adaptive, long-term flood risk management plan.
Context: Tidal flood risk on the Thames