IMPACTS OF LINEAR INFRASTRUCTURE: BIODIVERSITY, CLIMATE, AND COMMUNITIES

This report is concerned with the interrelated nature of the impacts that linear infrastructure can have on biodiversity, climate resilience, and communities and how those impacts are considered in a structured way in the planning and design of linear infrastructure projects. The report does not dive deeply into these risks and impacts as they are understood and documented. Rather, the report presents a summary of potential impact areas as a basis for the effectiveness of the regulatory mechanisms employed to mitigate these risks.

Biodiversity

The impacts of linear infrastructure on biodiversity are generally well understood, with extensive research and literature available globally and within Asia. The LISA project conducted a detailed analysis of the published literature on the impacts of linear infrastructure on Asian species and ecosystems.36 While continuous research is needed to refine understanding of species- and location-specific impacts, and of the effectiveness of various design options,37 sufficient evidence exists to identify risks and adopt mitigation measures in the design and construction of individual linear infrastructure projects.

The risks to biodiversity depend on the type and scale of linear infrastructure and its location but can be both direct and indirect in nature. Possible direct impacts include:

• barriers to movement of wildlife—for example, fencing constructed alongside roads and railway lines;

• road and rail collisions—where increased traffic can lead to roadkill of migratory animals;

• electrocution of birds on power lines.

Indirect impacts on biodiversity can include:

• habitat loss and fragmentation—where linear infrastructure transects landscapes, it can reduce viable and safe habitats, and range, for native species;

• roads and access routes for other linear infrastructure facilitate increased human access to previously hard-to-reach locations—this can enable poaching of wildlife, illegal logging, and unplanned development, and may lead to introduction of exotic and invasive species. Figure 3 shows an example of the “fishbone” pattern of deforestation occurring over a decade in part of western Brazil.

• ecosystem degradation—because of landscape fragmentation and increased access, ecosystem integrity can be weakened leading to the loss of important ecosystem services.

Many measures can be adopted to mitigate the impacts of linear infrastructure projects on biodiversity, including design and technical solutions such as alignment that avoids wildlife habitat or takes account of bird flight paths. For example, in Spain, redesign of power lines and remediation of existing, dangerous pylons to reduce the risk of electrocution of birds have resulted in a marked increase in the population of the endangered Spanish Imperial Eagle. 39

Importantly, however, many of these impacts are cumulative and most severe when considered at a landscape level, rather than for individual projects. The cumulative impacts can be cascading where direct impacts on a particular species have flow-on effects for an entire ecosystem, while a linear infrastructure project may open the floodgates for further development by enabling access to a region. Accordingly, linear infrastructure must not be considered on a project-by-project basis but rather from a strategic perspective—both spatially and temporally—within a landscape.

Moreover, the relationship between cumulative impacts on biodiversity and risks to climate resilience and local communities is particularly pertinent given that ASEAN is home to significant biodiversity and exposed to extreme risks of climate change. Ecosystem degradation exacerbates disaster risks and, in turn, can have negative impacts on the long-term viability of infrastructure assets.

Climate

The relationship between climate change and linear infrastructure is complex and multidirectional; linear infrastructure development can both contribute to, and be impacted by, climate change. Climate change can also exacerbate other impacts of linear infrastructure, including effects on ecological health, as well as reducing the resilience provided by ecosystem services. The long lifespan of linear infrastructure projects means that future climate scenarios must be considered when assessing linear infrastructure projects. Direct effects of linear infrastructure on climate change include greenhouse gas emissions that result from deforestation and other land use change. Indirect emissions also increase due to increased road traffic or energy consumption. New projects can also have a positive effect when rail lines replace road traffic or renewable energy replaces fossil fuels. The climate change implications of linear infrastructure development will thus be both case-specific and involve multiple considerations, including overall system planning (e.g., energy or transportation arrangements).

Linear infrastructure is also at risk of both the immediate and longer-term effects of climate change.The economic costs of climate change and extreme weather events on infrastructure are documented around the world.40 Myanmar, the Philippines, and Thailand all feature in the top 10 countries most affected by climate change between 2000 and 2019.41 While Myanmar’s status in the Global Climate Risk Index is due to the severity of Cyclone Nargis in 2008,42 it continues to suffer from floods and landslides that cause extensive damage to roads.The Philippines is frequently exposed to tropical cyclones that can have major impacts on linear infrastructure, as well as on lives and livelihoods.43

Changes to the natural environment that result from climate change have the potential to affect the long-term financial viability of the investments in infrastructure assets,”44 such as increased risk of landslides that may require costly engineering solutions to avoid constant repairs. Oftentimes, infrastructure is developed on an assumption that certain ecosystem services will provide a degree of resilience to natural hazards (e.g., mangroves protecting against storm surges) but climate change can erode such resilience, exposing infrastructure assets to unforeseen risks. Accordingly, resilience to natural hazards, particularly in the context of climate change, requires comprehensive consideration as part of linear infrastructure development.

Communities

The impacts of linear infrastructure on local communities can also be positive and negative. Positive impacts include increased access to services and facilities, as well as short-term employment opportunities during construction. Negative impacts may be less obvious, such as lost access if a community is bypassed, increased road safety risks, restrictions on land access, or increased environmental health risks such as those arising from proximity to a gas pipeline.

Affected communities may view increased accessibility from roads or railways as positive or negative. While some communities desire increased access to population centers, new transportation corridors may exacerbate land disputes and conflicts or be seen as a security risk. Social objectives need to be clearly defined during the planning process.

Given linear infrastructure generally traverses large distances, projects often affect multiple communities and individuals with different tenure over their lands,45 including communities where tenure may be based on traditional or customary land use and not formally recognized under national systems. Historically, major linear infrastructure projects have been treated as political or economic development priorities and used to justify the voluntary or involuntary resettlement of people from their land. The negative social and economic effects on people who are subject to relocation and resettlement can be extreme, despite efforts to compensate or resettle affected people. Even where people are not physically displaced by land acquisition or resumption, linear infrastructure projects may have negative impacts from broader land use changes that result in economic displacement.

The impacts of linear infrastructure on communities also need to be understood in the context of how inclusivity and resilience are intertwined. Often, the most vulnerable members of society are most affected by natural disasters and a changing climate. This interrelationship has been highlighted in the Global Climate Risk Index 2021. 46

The Covid-19 pandemic has reminded us of the fact that both risk-affectedness and vulnerability are systemic and interconnected; globally, 51.6 million people had to simultaneously deal with the impacts of floods, droughts, or storms while trying to contain the pandemic and deal with its consequences. It is therefore important to strengthen the resilience of the most vulnerable against different types of risk (i.e., climatic, geophysical, economic, and health-related risks). The potential impacts of linear infrastructure development, therefore, also depend on the vulnerabilities of communities and other biophysical risks associated with the project.

Inclusivity in linear infrastructure development means not just considering potential community impacts in project design, but providing opportunities for meaningful participation by potentially affected people throughout all phases of the linear infrastructure project lifecycle (see Figure 4 and, for a more detailed discussion, Annex 2 on linear infrastructure project cycles). This includes ensuring community needs and aspirations are incorporated into land use and other planning processes that set parameters for future linear infrastructure, as well as making information about individual project proposals available and undertaking meaningful consultation during their design, evaluation, and construction. It also includes providing accessible grievance mechanisms under which concerns can be raised and appropriately addressed.