IB Geography 6.2.2 Environmental Impacts of Global Flows Notes

Global Flows Can Concentrate Environmental Harm in Particular Corridors

1. Trade and travel connect distant producers and consumers, but ports, airports, shipping lanes, roads and logistics hubs concentrate emissions in specific places.
2. A flow can therefore be global in origin and destination while its most severe pollution is experienced locally by coastal or urban communities.
3. The environmental cost is often separated from the consumer because the consumer sees the final product rather than the energy, waste and emissions produced along its route.
4. Scale matters: an oil spill can devastate a coastal ecosystem, while repeated fuel combustion contributes both to local air pollution and cumulative climate change.

Shipping Lanes Create Several Forms of Localized Pollution

1. Ship engines emit sulphur oxides, nitrogen oxides and particulate matter, which affect air quality most directly around busy routes, ports and coastlines.
2. Sulphur and nitrogen compounds can contribute to acid deposition, while fine particles can enter the lungs and increase health risks.
3. Oil spills produce acute contamination, but routine discharges, antifouling chemicals, noise and waste can also degrade marine environments.
4. Ballast water can move organisms between ecosystems, creating biological pollution when a non-native species survives, reproduces and disrupts food webs.
5. The same route may carry different risks at different scales: exhaust affects nearby populations, carbon dioxide contributes to global warming and invasive species alter receiving ecosystems.

A Carbon Footprint Follows Emissions Through the Full Life Cycle

1. Direct emissions occur where fuel is burned or a process releases greenhouse gases.
2. Indirect emissions occur in the production of electricity, materials, packaging, infrastructure and services used by the activity.
3. A product footprint may include raw-material extraction, processing, manufacture, refrigeration, transport, retail, use and disposal.
4. Greenhouse gases are converted to carbon-dioxide equivalent so gases with different warming effects can be compared in one measure.
5. The result depends on the system boundary, so two footprint estimates are not comparable unless they include similar stages and use the same functional unit.
6. A related but different indicator is the carbon component of the Ecological Footprint. It converts carbon dioxide emissions into the area of biologically productive land needed to absorb them, expressed in global hectares rather than tonnes of carbon-dioxide equivalent. In the 2026 National Ecological Footprint and Biocapacity Accounts, carbon rose from 42% of the total footprint in 1961 to 60% in 2023.

Food Footprints Are Not the Same as Food Miles

1. Food miles measure transport distance, whereas a food footprint includes production, land-use change, processing, refrigeration, packaging and waste.
2. Production can dominate the footprint of emissions-intensive foods, so a nearby product is not automatically lower-carbon than an imported alternative.
3. Transport becomes more important when food is air-freighted, moved in small vehicles or stored for long periods under refrigeration.
4. A fair comparison should use an equivalent quantity and quality of food, then state which life-cycle stages have been included.

Goods Carry Embodied Emissions Through Supply Chains

1. A phone, shirt or vehicle embodies emissions from materials, factory energy, component transport, assembly and distribution before purchase.
2. Container shipping is efficient per tonne-kilometre, but the enormous volume of trade makes its cumulative emissions significant.
3. Fast delivery can shift freight from sea to air, exchanging shorter delivery time for much higher emissions per unit moved.
4. Repair, reuse and longer product life can reduce annualized emissions when they prevent an equivalent replacement from being produced.

The Footprint of People Depends Strongly on Mode and Occupancy

1. Walking and cycling have very low operational emissions, while private vehicles divide fuel use among the people carried.
2. Public transport has a lower footprint per passenger when vehicles have high occupancy, but lightly used services may perform less well.
3. Aviation creates substantial emissions per passenger on many routes and also produces non-carbon warming effects at altitude.
4. Digital meetings can replace some trips, but the avoided journey must be compared with energy used by devices, networks and data centres.

Footprint Claims Need Consistent Boundaries and Cautious Interpretation

1. Absolute emissions show total pressure, while emissions per person, passenger-kilometre or kilogram of product answer different questions.
2. Consumption-based accounting assigns emissions to the place where goods are used, whereas territorial accounting records emissions where production occurs.
3. Outsourcing production can lower a country's territorial emissions without lowering the emissions caused by its consumption.
4. A low-carbon label is most credible when its data source, year, boundary and method are disclosed.
5. Offsets do not erase the original emission and should be assessed for additionality, permanence and the risk of double counting.

Responses Work Best When They Reduce Both Local and Global Costs

1. Cleaner fuels, shore-side electricity and emission-control areas reduce exposure near ports and coasts.
2. Efficient ship design, slower steaming and low-carbon fuels can reduce greenhouse-gas emissions, although cost and fuel availability constrain uptake.
3. Life-cycle standards and supply-chain disclosure help purchasers compare products, but weak or inconsistent methods can support greenwashing.
4. Compact settlement patterns, reliable public transport and alternatives to frequent flying can reduce the footprint of people flows.
5. The best policy combination measures emissions consistently, targets the largest life-cycle stages and protects communities located beside transport infrastructure.