Mobility is fundamental. It is not only a requisite for economic development but an intrinsic property of life itself. Mobility ensures the exchange of resources, genes, and species, as well as of people and goods. Without sufficient mobility, genetic exchange will cease, populations crumble, trade will fade, and economies shrink.
To ensure sufficient mobility in the future, the EU has been working on unifying transport arenas, developing corridors for fast intermodal transport, and demounting legal, technical, and physical barriers to ensure sufficient mobility in the future. In the same spirit, European environmental policies aim at developing networks of protected areas connected by corridors of green infrastructure. However, transport (grey) and ecological (green) infrastructure rarely interact well. Every so often, both networks intersect, clash, and compete for the same space. As a result, millions of animals are killed by traffic, ecosystem processes become disrupted, and landscapes fragmented; all contributing to the ever-growing loss of biodiversity.
Very few places on Earth are left that are not yet directly or indirectly affected by infrastructure. Infrastructure also paves the way for future land use change, urban development, and human settlements, which cumulatively threaten nature. The transport sector is closely connected, directly and indirectly, to the five major drivers of global biodiversity loss identified by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) in the Global Assessment Report on Biodiversity and Ecosystem Services:
- Changes in land and sea use: transport infrastructure and its traffic impose movement barriers to wildlife and cause millions of animal deaths, disrupt ecological processes and shatter living spaces into smaller and isolated fragments. This entails the transformation, degradation, and fragmentation of natural habitats, changing the structure and functionality of ecosystems and generating a cascade of changes at a landscape level. Infrastructure development paves the way for secondary resource depletion that further aggravates the loss of biodiversity and existential ecosystem services.
- Direct exploitation of organisms: infrastructure facilitates access to previously remote natural areas / road-less areas and allows the overharvesting, poaching, and trafficking of wild animals and plants for food, medicine, materials, or recreation.
- Climate change: the transport sector significantly contributes to climate change, accounting for about two-thirds of global oil consumption, one-third of all energy use, and a quarter of the world’s energy-related carbon dioxide emissions. Emissions lead to the rise of temperature, precipitation, sea level, and the likelihood of extreme weather events.
- Pollution: construction, use, and maintenance of infrastructure cause the contamination of air, water, and soil by chemicals, plastics, nutrients, pathogens, noise, and light with consequent effects on wildlife and people. Infrastructure directly affects between 15-20% of terrestrial ecosystems.
- Invasive alien species (IAS): transport and infrastructure introduce and spread non-native species that cause harm to native biodiversity, ecosystems, and human health.
The impacts of infrastructure will only increase considering the forecasts in transport development and climate change. Forecasts by the G20 (the intergovernmental forum containing most of the world’s largest economies) anticipate a 60% increase of global transport infrastructure by 2050, compared to the 2010 level. Automobile traffic is expected to double and future roads may be populated by over 2 billion vehicles. Worldwide, according to the Global Infrastructure Outlook, more than $2 trillion of transport infrastructure investments will be needed each year until 2040 to fuel the intended economic development. Rapid urbanisation, surging demand for freight services and for increased personal mobility will put pressure on stakeholders to accelerate infrastructure development.
If ‘business as usual’ prevails, future outlooks for a sustainable development are bleak. New and better ways to meet our basic needs for communication, mobility, and transport, while enhancing conditions for biodiversity and people are needed. This task requires a holistic shift in the mindset of politicians, planners, corporations, and private companies – as well as among public customers. Climate change adaptation and mitigation, and biodiversity protection must go hand in hand with improvements in funding, design, and maintenance of infrastructure. This requires solid knowledge of the impacts and how they can be prevented, reduced, or compensated for. Deploying appropriate measures is not an easy task but it can build on decades of experience and research.
Communication and knowledge transfer are essential, as well as a broad understanding of how biodiversity and infrastructure interact. When done responsibly, infrastructure development can maintain the health of the ecosystem and provide the required mobility services. Upgrading existing infrastructure offers even opportunities to implement higher biodiversity standards and produce a net-gain for nature.
This Chapter introduces basic concepts about ecological effects that are relevant for applying the mitigation options described in the following chapters of this handbook. It aims to assist readers understand the effects of infrastructure on nature and inspire planners, engineers, and ecologists to develop innovative measures that can make future transportation networks into valuable assets for supporting biodiversity and human well-being.
However, even with the best mitigation and restoration efforts, new infrastructure will always result in some loss of biodiversity. This is why the main aim in mainstreaming biodiversity in transport infrastructure must be to reduce the demand for new infrastructure. The overall concept of transportation must evolve to achieve sustainable development. To fully benefit from the tools provided in this handbook, stronger policies, new investments, changed behaviours and mindsets are required.