Transport and Global Environmental Challenges

The Problem

• Humans need mobility.
• Transport is becoming faster and more efficient.
• Current modes of mobility are unsustainable, often viewed as a basic human right.
• Transport systems are mostly motorised and dependent on non-renewable fossil fuels (Sultana et al., 2019; Black, 2010).

Toxic Chemicals and Pollution

• Cars and vans are the biggest source of toxic chemicals in our air (cleanairhub.org.uk 2025).
• Switching one car journey a month for a bus trip could result in a billion fewer car journeys each year in the UK.
• Taking the train produces nearly 80% less carbon emissions than driving.
• 50% of short journeys in towns and cities walked or cycled could save enough carbon to power every home in Manchester, Bristol, or Liverpool with electricity.

Expert Opinion

• Professor Tim Schwanen (Oxford’s Transport Studies Unit): "Our obsession with vehicles and planes is bad for our health, bad for our lives, bad for equality and, yes, bad for the environment. We need to give people and places proper alternatives to the car and long-distance mobility.”

Transport and Sustainability Links

• Geography, Space and Place
• Economy
• Environment
• Society
• Behaviour
• Policy
• Planning

Major Environmental Effects of Transport (Middleton, 2018)

• Land: Use and degradation, excavation for minerals, solid waste generation.
• Biospheric: Introduction of immigrant species, barriers to migration.
• Atmospheric: Greenhouse gas emissions, particulates, fuel emissions, noise and vibrations.
• Hydrological: Contamination of water from runoff and spillages, modifications of hydrological regimes.

United Nations Sustainable Development Goals (SDGs)

• Transportation plays a crucial role in achieving these goals.
• SDG 9: Industry, Innovation, and Infrastructure
  • Target 9.1: Develop quality, reliable, sustainable, and resilient infrastructure, including transportation infrastructure.
  • Target 9.4: Upgrade infrastructure and retrofit industries for sustainability and clean technologies.
• SDG 11: Sustainable Cities and Communities
  • Target 11.2: Provide access to safe, affordable, accessible, and sustainable transport systems for all.
  • Target 11.6: Reduce the adverse environmental impact of cities, including air quality in transport planning.
• SDG 13: Climate Action
  • Target 13.1: Strengthen resilience to climate-related hazards.
  • Target 13.2: Integrate climate change measures into national policies, focusing on mitigation in the transport sector.
• SDG 3: Good Health and Well-being
  • Target 3.6: Reduce road traffic injuries and deaths.
• SDG 7: Affordable and Clean Energy
  • Target 7.3: Double the global rate of improvement in energy efficiency in the transport sector.
• SDG 8: Decent Work and Economic Growth
  • Target 8.2: Achieve higher levels of economic productivity through technological upgrading and innovation in transport.
• SDG 12: Responsible Consumption and Production
  • Target 12.3: Halve per capita global food waste and reduce food losses.
• SDG 15: Life on Land
  • Target 15.1: Ensure the conservation and sustainable use of terrestrial and freshwater ecosystems, promoting sustainable land use and combating desertification.

Global Greenhouse Gas Emissions by Sector (2016 Data)

• Total global greenhouse gas emissions: $49.4$ billion tonnes CO₂eq.
• Agriculture, Forestry & Land Use: $18.4$
• Waste: $3.2$
• Industry: $5.2$
• Energy: $73.2$
  • Transport: $16.2$
    • Road Transport: $11.9$
      *Electrifying the road transport sector and transitioning to a fully decarbonized electricity mix could reduce global emissions by $11.9$.
    • Aviation: $1.9$
    • Shipping: $1.7$
    • Rail: $0.4$
    • Pipeline: $0.3$
  • Energy use in buildings: $17.5$

Transport Emissions

• Emissions are caused by road transport, shipping, aviation, and trains.
• Decarbonising these sectors may be particularly difficult.

Importance of Transport

• Enabling accessibility and social inclusion.
• Ensuring economic success and fostering regional development.
• Transport is inherently geographical, affecting movement.
• Transport must increasingly be sustainable.

Broad Approach to Transportation

• How space is planned affects our environment and lived experience.
• Are we building cities for cars or cities for people?

Transport and Space

• The spatiality of transport networks.
• Taking supply to demand and demand to supply.

Three Major Issues of Unsustainable Transport

• Transport emissions and climate change.
• Road transport, human health, and road trauma.
• Oil dependency and peak oil.

Common Issues in Unsustainable Transport (Glover and Low, 2020)

• Environment:
  • GHG emissions.
  • Ecological costs of roads.
  • Air and water pollution.
  • Car-dependent urban design.
  • Low urban quality of life.
  • Ecological footprint of modes.
• Social:
  • Road trauma.
  • Inequitable mobility and transport disadvantage.
  • Obesity and sedentary living.
  • Reduced children’s independent mobility.
• Economic:
  • Oil dependency and energy insecurity.
  • Peak oil.
  • Costs of automobility.
  • Car dependency.
  • Energy inefficiency.

Modes of Road Transport & Pollution

• Cars are a major contributor, but other forms include heavy goods vehicles (HGVs), light vans, buses and coaches, motorcycles, and bicycles.

Environmental Impacts of Transport

• First-order impacts:
  • Land take, severance, and displacement.
  • Loss of aesthetic landscape quality.
  • Hydrological disruption and water pollution.
  • Impacts on the biosphere.
  • Noise.
  • Air pollution.
  • GHG emissions.
  • Resource depletion.

Impacts on the Biosphere

• Facilitates and hinders movements of flora and fauna and opens up new routes for species dispersal.
• Human colonizers have moved species (e.g., Grey Squirrels).
• Species can ‘hitch a ride’ and have devastating consequences on local species.
• This can include diseases that can now spread at an alarming rate – COVID-19 became globally distributed in 3 months.
• EG. Reindeers – disturbance of migration routes by roads and power-lines.

Loss of Aesthetic Landscape Quality

• ‘Cuts’ such as the M3/M27 link at Twyford Down in Hampshire damage landscapes…
• Elsewhere, plans for road or rail building (whether the projects proceed or not) can produce planning ‘blight’…
• Highly subjective: Some transport features become valued heritage sites (e.g., Ribblehead Viaduct, Cumbria).

Hydrological Disruption and Water Pollution

• Roads are non-porous, producing large amounts of run-off during heavy rain.
• Drainage systems often flow into the local river network, sometimes overloading small rivers and causing downstream flooding.
• Oil, diesel, and rubber residues get washed into water courses.

Noise Pollution

• Over $100$m people in OECD countries subjected daily to road traffic noise of over $65$dB(A).

Air Pollution

• About $400$ polluting compounds are emitted by petrol and diesel vehicles. The main pollutants are:
  • Carbon monoxide: Exacerbates cardio-vascular disease.
  • Ozone: Eye and throat irritant.
  • Nitrogen oxides: Lung irritant.
  • Hydrocarbons and Volatile Organic Compounds (VOCs): Carcinogenic, impacts on foetal development.
  • Lead: Impairs hemoglobin and attacks nervous system, impairs learning in children (banned in petrol in UK).
  • Particulates: Small particulates irritate lungs, esp. from diesel.

Health Impacts of Air Pollution

• Hospital admissions and fatalities for respiratory conditions rise in cities when air pollution concentrations peak.
• Estimated $24,000$ premature deaths in UK per annum.
• Sick leave and hospitalization costs due to air pollution amount to $0.4$% of EU GDP.

Global Death Toll from Air Pollution

• Various studies estimate millions of deaths annually from air pollution.

The Urban Atmosphere

• Air pollution: Increased temperatures in urban spaces, poor air quality, smog, episodic health hazards.
• Exacerbated by intense industrial production, vehicle transportation, density of buildings, consumption of resources, volume of waste.

Health Effects of Major Air Pollutants

• SO₂: Impaired function of airway and lungs, increased prevalence of chronic bronchitis and permanent lung damage.
• SPM: Respiratory problems, effects dependent on particle size and concentration.
• NOx: Increases bronchial reactivity, reversible and irreversible lung damage, sensitizes the lungs to other pollutants.
• CO: Reduces oxygen in the blood, affecting brain, heart and muscle. Developing foetuses very vulnerable.
• O₃: Inflammation of airway, reduced lung function. Can inhibit immune system response.
• VOCs: Respiratory problems. Contributes to formation of ground-level ozone.
• Pb: Effects haemoglobin production, central nervous system and brain function.

Transport as a High-Carbon Sector

• For every litre of petroleum, diesel or aviation fuel combusted, about $2.5$ kilograms of carbon dioxide is released to the atmosphere.
• Transport was responsible for $7866$ million tonnes of carbon dioxide emissions in 2016 (with $5853$ tonnes from road transport alone), accounting for around one-quarter of global emissions (IEA 2018).
• Carbon dioxide emissions from transport sub-sectors in 2016 were: road (74 per cent), air (12 per cent) and water (11 per cent) (IEA 2018).

Unequal Distribution of Transport Emissions

• The per-passenger per-kilometre emissions (in grams) in the EU are as follows: air – $285$, large car – $158$, small car – $104$, motorcycle – $72$, bus – $68$ and train – $14$ (EEA 2019).
• High and middle-income nations produce most transport GHG emissions.
• Sims et al. (2014) reported that $80$ per cent of motorized passenger kilometres were made by $10$ per cent of the global population, mostly in OECD nations.

Carbon Emissions by Sector in the UK

• The transport sector is a persistent emitter despite significant drops in other sectors…

Geographic Disparity of Greenhouse Gas Emissions

• Anthropogenic GH emissions (CO2, BC, CH4, and N2O) averaged from 1970 to 2018.

Annual CO2 Emissions by World Region

• This measures fossil fuel and industry emissions.

Products of Crude Oil

• Crude oil may be refined into a wide range of products used in transportation, heating, and road-making.

Cumulative CO2 Emissions from Oil, 2021

• Data on cumulative CO2 emissions from oil usage by country

Oil and Gas Basins

• Oil and gas basins are spread throughout the world.
• Pipelines: The combined length of these pipelines is more than $1.18$ million km ($730,000$ miles) – enough to circle the Earth $30$ times.

Gas Transport

• Liquefied Natural Gas (LNG) is moved by tanker.

Wider Resource Depletion from Transport

• Large volumes of energy, water, metals and aggregates used at various stages of the ‘production’ of transport.
  *Manufacture, operation, maintenance and scrapping of vehicles, construcion and decommissioning of infrastructure.
• The operation of electric trains and battery cars is NOT non- polluting.
• Pollution transferred from linear (rail, road) to point sources (power stations).

Narrow Approaches

• Greener technologies are developing, particularly for cars & taxis.

Electric Vehicles

• EV usage is growing.

CO2 Emissions from Coal

• Amount of CO2 emissions from coal usage by country.

Broad Approaches

• Improving environmental impacts of transport.

Positive Trends

• Massive reductions in air pollution from transport.
• Long-run decline in rate of traffic growth.
• Lorry traffic down on 1990s.
• Buses are fuller.
• Slow revival of cycling on roads.
• Individuals are driving less and car ownership is no longer rising.
• Regulation and financial incentives are moving in the right direction.
• Greener technologies are developing.

Investment in Greener Transport Networks

Current Transport Policy Initiatives

• Measures to achieve:
  • Reduced trip distances.
  • Reduced trip frequencies.
  • Increasing vehicle occupancy.
  • Shifting travel to non-car modes.

1. Reduced Trip Distances

• Increased density (increasing housing unit density, urban infill development densification).
• Mix land uses (mixed-use zoning, vertically mix buildings).
• Increase local access to jobs (jobs-housing balance, mixed-use zoning, reduce parking requirements, work from home policies, reduce office space in central areas).
• Last-mile delivery systems.

2. Reduced Trip Frequencies

• Mix land uses (mixed-use zoning, vertically mix buildings).
• Increase local access to jobs (reduce parking offer, work from home policies, reduce office space in central areas).
• Improve IT and Internet coverage.
• Local facilities for workspaces – ‘third spaces’ in neighbourhoods.

3. Increasing Vehicle Occupancy

• Policies to make this attractive (make it difficult to park - reduce parking offer, make fuel REALLY expensive).

4. Shifting Travel to Non-Car Modes

• Increase public transport access (add transit routes, increase service frequency, transit-oriented development, intermodal infrastructure (bike share, bike racks).
• Improve public transport service (real-time arrival information at stations, bus stops etc.; premium service for additional charge, additional amenities on transit vehicles and hubs (wifi, food, shopping etc).
• Congestion reduction (charging etc. Examples – London, Athens).
• Improve walkability (traffic calming, restriction, pedestrianisation etc).
• Improve bikeability (bike lanes, traffic calming etc.).
• Reduce parking supply.

Example 1: Transit Oriented Development and ‘Densification’ or ‘Compact City’ - Helsinki

• Goal – to create “compact, walkable, pedestrian-oriented, mixed-use communities centred around high- quality [public transit] systems” (Sultana et al., 2019).

Densification in Urban & Transport Planning

• Definition: Densification refers to the increase in population and development intensity within existing urban areas.
• Related concepts/language: Compact City, 15-minute city, infill, intensification.

Densification Practices in Helsinki and the Wider Region

• Construction of new dwellings and offices in former industrial and harbour areas around new transport hubs has been an important part of the new densification trend.
• Densification is expected to play a big role in reducing transport-related environmental problems.
• To reach its goal of carbon neutrality by 2035, the City of Helsinki needs to reduce traffic-sector greenhouse emissions by $69$% (City of Helsinki, 2018).

The Compact City Concept

• The compact city is an urban planning model that promotes high population density, mixed land use, and efficient transportation to create a sustainable and walkable urban environment.
• Origin: Coined by Sir Peter Hall in the late 20th century.

The ‘15-minute City’

• The 15-minute city concept, popularized by Carlos Moreno, envisions urban planning where residents can meet most of their daily needs within a 15-minute walk or bike ride from their homes.

Transport Advantages of Densification

• Sustainable Transportation: Supports public transportation, walking, and cycling by creating walkable neighbourhoods.
• Environmental Benefits: Reduces the need for additional infrastructure and preserves green spaces.

Example 3: Last Mile Delivery

• Last-mile delivery is the final step in the delivery process, when a package is transported from a distribution centre to a customer's home. It's also known as final mile delivery. Challenges
  • Last-mile delivery is often expensive and time-consuming.

Restrictions on Cars in Cities – Example 4 - Athens

• Implemented license plate restrictions in the city centre.
• License plates ending in an even number are allowed in the city centre on even calendar dates.
• Odd numbers on odd calendar dates.

The Urban Atmosphere & UK Policy Change

• Initiatives to improve urban air quality:
  • Clean Air Act (CAA) 1953: A response to London’s Great Smog of 1952. Introduction of ‘smoke control areas’ Relocation of power stations from cities and the increased heights of chimneys (Brimblecombe, 2007)
  • The Congestion Charge Zone (CCZ) 2003: implemented to reduce traffic congestion in central London.

Restrictions on Cars in Cities – Athens

• Drivers came up with numerous legal and illegal strategies to get around restrictions …..
• Buying a second car with the other number plates – can increase pollution because they buy older second cars
• Shuffling driving trips but still doing the same number
• Cheating (driving where they think they will not be policed)

Urban Transport Sustainability in Curitaba

• Ultimately urban environmental action boils down to money and political will E.G. Curitiba, Brazil:
• Innovative, low-cost transport and land use.
  *Public transport infrastructure and dedicated bus lanesReduced congestion and lowered air pollution
  *Average private vehicle uses 30% less fuel than the average for 8 comparable Brazilian cities
  *Pedestrianised precincts, bicycle lanes and green spaces are being introduced (Middleton, 2013)

Policies, Politics, Planning and Future Technologies

• Wider conceptions about what is needed are necessary rather than relying on technological development to enable sustainability
• We need to question our values about how and when we move