Road construction opens a “Pandora’s box” of negative impact, according to the authors of the paper, published this month in Current Biology. These include deforestation, animals hunted to extinction, land grabs by speculators betting on development, and wildfires.
“We’re living in the most explosive era of infrastructure expansion in human history. [There will be] an unprecedented avalanche of projects,” says Bill Laurance, an environmental scientist at James Cook University in Australia and lead author. “Roads are like a metastasising cancer. Once you have cut the [forest] to build a new road, it often becomes very hard to control the spread of secondary and tertiary road networks.”
Roads are part of a plan by the 20 largest economies to double global infrastructure investment by 2030. At a G20 meeting in Brisbane, Australia, in November 2014, governments said they would commit US$60-70 trillion to new infrastructure projects by that time.
Then by the middle of this century, there will be 25 million kilometres of new highways, according to the International Energy Agency, enough to circle the world more than 600 times — and at least 90 per cent of these roads will be built in developing countries.
Roads can deliver greater social and economic growth, the authors of the Current Biology paper acknowledge. They can help rural communities get better healthcare, education and employment as well as promote national and international trade, energy, agriculture and transport.
“We’re not anti-development, we’re anti-environmentally destructive development,” explains Laurance. “We have a very deep sense of concern about what’s going on.”
The study, which also covers projects such as energy and mining, includes nine recommendations for governments, donors and the public (see box) to help limit the environmental impacts of roads. These include keeping some areas without roads, reforesting roads built for time-limited projects and educating infrastructure funders about environmentally responsible construction.
Protect remaining roadless areas.
Keep roads unpaved in biodiverse areas.
Ensure environmental impact assessments (EIAs) include indirect effects/induced impacts of infrastructure.
Build projects without roads where possible (for instance, use helicopters instead) or close roads after construction and re-vegetate.
Lenders should be more involved in project design.
Improve tools to support integrated land use planning (for example, biodiversity maps and geospatial road data).
Lenders need to recruit talented and assertive environmental and social specialists.
Increase pressure on environmentally negligent institutions.
Pressure lenders to be environmentally aware and make conservative decisions on infrastructure.
Road kill: Recommendations to protect biodiversity
But there is a “juggernaut of investors lurking to push these projects through even if responsible lenders say no”, says Alan Ziegler, an environmental scientist at National University of Singapore, who has published research showing that investors often don’t understand the impacts of road networks they support.
“Countries should consider if projects truly will serve the long-term interest of their nations and all their people, and not the short-term interest of a handful of privileged local and foreign investors,” Ziegler says.
The Current Biology study adds that governmental and non-governmental organisations must increase pressure on companies with low environmental safeguards.
> Link to the abstract of the Current Biology paper
> Link to International Energy Agency’s Global Land Transport Infrastructure Requirements report