By 2050, it’s projected that 25 million kilometres of new paved roads will be developed globally – enough to encircle Earth more than 600 times. Roughly 90 per cent of those roads will be built in tropical and subtropical regions.
This forecast is outlined in Economic, Socio-Political and Environmental Risks of Road Development in the Tropics, a study released in October 2017, which also addresses just how this swathe of new road infrastructure will impact on the these equatorial centres.
Professor Bill Laurance, who is Director of James Cook University’s Centre for Tropical Environmental and Sustainability Science, co-authored the study, and for many years has been involved with myriad research projects into the effects of road infrastructure across developing countries in South-East Asia, Africa, South America and Asia-Pacific.
He also co-authored another recent study – Roads to Riches or Ruin? – which identified many perils to people and nature from the global road-building explosion. The paper was co-authored by Irene Burgués Arrea, an economist with the Alliance of Leading Environmental Researchers & Thinkers in Costa Rica.
“We’ve been working on roads and infrastructure issues in a lot of different places around the world for a long time. We’ve worked in the Amazon for the past 25 years, Asia Pacific for 40 years and in Africa for 20 years. Our work now spans scores of developing nations such as Brazil, Indonesia and the Republic of Congo,” Prof. Laurance says.
“The construction of new roads can determine where and when rapid environmental changes occur – the landscape changes, habitats change, wildlife populations change – it has all kinds of effects in these fragile environments.”
Through their research, Prof. Laurance and Ms. Burgués Arrea found the most urgent priority, especially for developing countries in Asia-Pacific, Africa and Latin America, is limiting the millions of kilometres of new roads being planned or built in high-rainfall areas.
“This is where ambition for quick profits meets nearly impossible engineering,” Prof. Laurance says. “Rainfall-drenched roads develop pot-holes, giant cracks and landslides so fast it’s nearly unbelievable – they can quickly turn into giant money-losers.
“Many of these environments can get a lot of rainfall in short periods of time, and it’s very hard to engineer roads that handle so much waterflow without destroying the pavement surface or its supporting road base.”
The problem, he says, is the lack of planning and consideration of the environmental conditions of the area, particularly in these equatorial regions.
“We’ve seen so many expensive roads built just a few years ago in these regions, but they’re impassable now, and there’s a really serious problem with how they’re managed,” Prof. Laurance explains.
“A lot of different nations don’t understand how much long-term investment will be needed to keep their roads functioning in high-rainfall areas, and the tremendous environmental costs of building roads in forests and other high-value environments.
“The public often ends up with major debts from failed roads. A few road developers and politicians can get rich, but vital development and economic opportunities are easily squandered.”
Prof. Laurance says corruption is a serious problem in many nations. “Road contractors will often cut corners on building materials, constructing substandard roads while pocketing the extra profits. These illicit practices are alarmingly widespread in many poorer nations.
“Who’s accountable? Many contractors undercut things because there’s inadequate compliancy measures in place for road construction or maintenance, and that’s not just in developing nations,” he says.
“You could build 500 kilometres of new road pavement, but it could only take a few bad sections of the road for it to fail. The advantages of that road are then highly diminished.”
Prof. Laurance blames logging companies for some of the problems. “They promise to build roads and schools for local communities, but once they’re done logging the maintenance stops,” he says.
“The timber is gone and the local residents are left with roads and schools that are collapsing. This can lead to serious social conflicts.”
“In South America, we found that 95 per cent of all the deforestation in the Amazon basin occurs within 5.5 kilometres of a legal or illegal road, and there are a lot of illegal roads out there,” Prof. Laurance notes.
“Our studies show that legal roads are often surrounded by a spider web of illegal roads, which hugely increases the footprint of deforestation.”
Through research, Prof. Laurance estimates there are roughly 3 kilometres of illegal road for every kilometre of legal road in the Amazon Basin.
“Deforestation spreads like an aggressive cancer along all these roads.”
While Prof. Laurance’s research primarily concerns developing countries in equatorial regions, he notes that the economic, social and environmental risks of road expansion are important in Australia as well.
For example, Cape York Peninsula contains a wealth of tropical ecosystems that, biologically and climatically, are similar to the developing nations he studies.
“Australia has quite good road engineering, but if you spend time in Cape York, you see it is prone to the same flooding rains and cyclones that plague many developing nations,” Prof. Laurance says.
He is particularly concerned about the effects of climate change on that specific region.
“The climate is getting warmer, but one thing that is really hard to predict is rainfall. For Northern Australia, which already has highly variable rainfall, the CSIRO and the Bureau of Meteorology have both concluded that there’s low predictability for rainfall there in the future.
“That’s worrying for the future, because ambitious plans for agricultural expansion across Northern Australia rely crucially on stable and secure supplies of rainfall.”
Likewise, he says climate change and increases in the chances of flooding need to be considered when building new resilient and sustainable infrastructure in Northern Australia and other tropical regions of the nation.
“Global warming – it’s a real game changer,” he adds.
“Many roads that are planned for wet, swampy or mountainous regions probably shouldn’t be built at all, and that’s based only on economic criteria.
“It’s remarkable how many nations, investors and lenders are failing to see the profound risks of road expansion in wet tropical environments, which are also the world’s biologically richest ecosystems.”
Prof. Laurance says road planning in tropical and equatorial regions of Australia and developing nations needs to thought out much more cautiously.
“The bottom line is it’s better to be really cautious and focus on development where it’s absolutely necessary and make smart decisions around that.”