We are living in the most aggressive era of road-building in human history. The International Energy Agency projects that by 2050 we will have another 25 million kilometres of paved roads on Earth – enough to encircle the globe more than 600 times. Nine-tenths of these roads will be built in developing nations, mostly in the tropics and subtropics, which sustain the planet’s most biologically rich and environmentally important ecosystems.
This modern road-building spree is terrifying ecologists like us, because we know that new roads often open a Pandora’s box of environmental ills – exposing vulnerable ecosystems to an influx of human colonists, hunters, miners and land speculators. In the Amazon, for instance, our research shows that 95% of all deforestation occurs within 5.5 km of a legal or illegal road. In Africa, roads bulldozed by loggers are crisscrossing the Congo Basin, allowing waves of poachers armed with modern rifles and snares to penetrate deep into forests. In just the last decade, two-thirds of Africa’s forest elephants have been slaughtered for their valuable ivory tusks.
Almost everywhere we look we see roads causing one environmental crisis after another. The same things are happening on Australia’s northern doorstep in Indonesia, Malaysia and Papua New Guinea. All three of these nations have ambitious plans to open up their last...