Air Pollution Management Strategies (DP IB Environmental Systems & Societies (ESS))

Revision Note

Alistair Marjot

Expertise

Biology & Environmental Systems and Societies

Air Pollution Management Strategies

  • Air pollution management strategies are designed to reduce harmful emissions and improve air quality in urban areas

  • These strategies focus on:

    • Reducing the sources of pollution

    • Promoting cleaner technologies

    • Encouraging sustainable urban living

Reducing the use of fossil fuels

  • One of the most effective ways to manage urban air pollution is to reduce the reliance on fossil fuels

  • This includes:

    • Promoting the use of renewable energy sources like wind, solar, and hydro to power cities

    • Improving public transport systems in cities to reduce car usage, e.g.

      • Electric buses

      • Efficient metro systems

    • Creating infrastructure for cycling, e.g.

      • More cycle lanes

      • Cycle-hire schemes

    • Pedestrianising city centres

Emission zones and car restrictions

  • Emission zones are areas where only vehicles meeting certain environmental standards are allowed to enter

    • Low Emission Zones (LEZs) restrict high-polluting vehicles, reducing air pollution in the city centre

    • For example, London has an Ultra Low Emission Zone (ULEZ) where only vehicles meeting strict emission standards can drive

  • Some cities also restrict car use on certain days or at peak times to decrease congestion and emissions

Catalytic converters

  • Catalytic converters are devices fitted to car exhaust systems that reduce harmful emissions

    • They contain catalysts that speed up chemical reactions to convert pollutants like nitrogen oxides and carbon monoxide into less harmful gases such as nitrogen and carbon dioxide

    • In many countries, it is compulsory for vehicles to have catalytic converters

Diagram of a catalytic converter showing gases from the engine (CO, NOx) entering, passing through a catalyst, and exiting as clean gases (N2, CO2).
Diagram of a catalytic converter with labeled parts: gases (CO, NO, O2) enter, pass through a honeycomb structure, and exit as CO2, N2, and O2.
Catalytic converters are designed to reduce the polluting gases produced in car exhausts

Growing trees and natural screens

  • Trees and green spaces play an important role in filtering pollutants from the air

  • Trees can reduce air pollution and improve air quality by:

    • Absorbing carbon dioxide

    • Trapping particulate matter

  • Natural screens such as hedges, tree lines and green walls can also help reduce pollutants near roads and buildings

Green walls and green roofs

  • Green walls and green roofs are covered with vegetation and can improve air quality by filtering pollutants

    • They also help regulate temperature, reducing the urban heat island effect

Exam Tip

Remember that some strategies reduce pollution at the source (e.g. reducing fossil fuel use), whereas others aim to manage the effects (e.g. planting trees). Although the first type is preferable, it is not possible for cities to remove all sources of air pollution, so a combined approach is required.

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Alistair Marjot

Author: Alistair Marjot

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.