Urbanisation and transportation

The second half of the 20^th century saw the world's population explode and become increasingly urban and mobile. Here's an inventory of the effects that urbanisation and transportation have had on mankind and its environment.

Urbanisation: in search of a sustainable city

The 20^th century saw the number of cities with more than 10 million inhabitants increase from 2 to 50 ⁽¹⁾. In 2007 and on a global scale, urban populations finally surpassed rural populations ⁽²⁾.

The first consequence of urbanisation is a modification of natural environments: economic development is usually accompanied by the concreting of surfaces (shopping centres, infrastructures, housing...), which is especially striking in coastal areas (Mediterranean...). Often rampant urbanisation leads to an uncontrolled urban sprawl that is not harmonious (warehouses, estates...). Since 1990, the surface of towns has increased by 20% while the population grew by only 6% ⁽²⁾, resulting in a reduction and fragmentation of natural areas.

Initially attracted by the need for labour, urban newcomers now tend to flee the countryside, the wars... However, the overcrowding of cities during economic recessions usually has a strong impact on humans: social problems (lack of housing, ghettos...), hygiene problems (sanitary problems in slums...) and well-being issues (noise, stress...). Noise, in particular, ranks as the num. 1 nuisance according to 25% of France's citizens ⁽¹⁾.

Urban life is the source of many forms of pollution: pollution of water, which is used, collected, treated and disposed of in the natural environment; pollution of air, by micro-particles, volatile organic compounds and greenhouse effect gases; noise, olfactory and visual pollution...

Currently, cities are rarely models of economic prosperity, social integration and harmony with the environment. Yet, gradually making sustainable cities is one of today's major challenges: the rural population continues to decline, and limiting the environmental impact of our lifestyle depends on population densities that are high enough to share a maximum of infrastructures (transportation...). Sustainable management of global resources and the local environment, social fairness and cohesion between territories, efficiency of the economic fabric: these are the challenges facing the 21^st century city. A goal that is still far from being achieved...

Transport: excessive dependence on oil

Whether we're talking about passengers or goods, the transport sector is still experiencing strong growth: 2% per year. Moreover, transport is 98% dependent on oil ⁽²⁾. It therefore easily becomes apparent that this sector is one of the main emitters of greenhouse effect gases (GHG) and pollutants (carbon monoxide, nitrogen oxides...). In France, transport is responsible for 26% of GHG emissions, mainly due to road transport (more than 80% of the sector's energy consumption) ⁽³⁾.

Land transport requires many infrastructures. Highways are flourishing in emerging economies, while the road mesh continues to become denser in developed countries. Accordingly, nearly 3,000 km. of additional roads should appear in France by 2025 ⁽²⁾. Railway systems are also gaining ground in many countries. All of these terrestrial infrastructures contribute significantly to the splitting up of natural habitats.

The airline industry is booming: the annual number of passengers will probably multiply by 2.3 between 2000 and 2020, reaching 3.5 billion passengers ⁽²⁾. The pollution that results from this traffic is therefore rapidly increasing. In addition to the pollution caused by kerosene consumption, planes are often singled out due to the noise pollution they cause in airport zones.

Maritime transport is the most frequently used method of transport for goods. It is worth noting that the GHG emissions per ton of cargo per kilometre are much lower than those of other transport methods. However, sulphur and nitrogen emissions have greatly increased, while those of land transport have decreased. Furthermore, the risk of accidents is still far from zero, and ship disasters responsible for significant marine pollution still regularly make headlines.

Transport strategies are frequently a leading topic of sustainable development policies. But the choices are often difficult, and investments are subject to strong sector-based pressure. Should a new TGV line or a third airport be built in the Paris area? Should the purchase of new cars be subsidised? Should investments be made in public transport? One thing is certain ⁽³⁾: in order to reduce the environmental impact of the transport sector, we will have to "transport smarter", by favouring those methods of transport that pollute the least, and to transport less, by reducing the volumes that transit (number of shipments, distances covered...).

Written by Florent Planas for "One year for the Planet" (translated by Anyword).

Find out more…

1. Fondation Nicolas Hulot, Ecologuide de A à Z (Le Cherche Midi, 2004)
2. Michel Barnier, Atlas pour un monde durable (Acropole, 2007)
3. ADEME (French Environment and Energy Management Agency)
4. For an example illustrating the difficulties facing political choices in the transport sector, read chapter 3 of Yves Cochet's book, Antimanuel d’écologie (Bréal, 2009).