It has been estimated that more than 15 million miles of road will be build by 2050, and this construction may inflict lasting, if not permanent, harm to global ecosystems. Now experts have drawn up a "global roadmap" showing planners where and how new roads should be built to avoid the worst of this damage.

Replacing lush grassland, towering forests, or grand mountains with vast expanses of flat asphalt and paint is undeniably "bad" for natural habitats, passively encouraging an industry that pumps out tar, greenhouse gases and groundwater toxins.

However, even after roads are paved, they still cause significant damage to ecosystems simply by fracturing and isolating habitats. Nature World News recently reported how roads like the Southland freeway have isolated entire groups of large and territorial predators, interfering with their natural way of life to such an extent that they begin to act erratically.

So what can we do about it? According to a study recently published in the journal Nature, a new "global roadmap" crafted by careful researchers ranks the potential of a road building site by comparing the benefit of completion to the expected adverse environmental impact.

"It's challenging but we think we've identified where in the world new roads would be most environmentally damaging," co-author Andrew Balmford from the University of Cambridge said in a statement.

"Roads often open a Pandora's Box of environmental problems," added lead author William Laurance of James Cook University in Australia. "But we also need roads for our societies and economies."

According to the study, a "beneficial road" is one that can so heavily improve upon the quality of agriculture in a region that it outweighs potential ecological damage.

"We focused on agriculture because global food demand is expected to double by mid-century, and new or improved roads are vital for farmers," explained researcher Gopalasamy Reuben Clements. "With better roads, farmers can buy fertilizers to raise their yields and get their crops to markets with far less cost and waste."

The study details how regions like Eurasia, Central America and Mexico, and the Atlantic region of South America, are all full of areas where roads are needed, and can be built with little environmental impact. However, vulnerable regions such as the Amazon, Southeast Asia and Madagascar should be handled much more carefully, and road building should be avoided there if at all possible.

"So much road expansion today is unplanned or chaotic, and we badly need a more proactive approach," Laurance added. "It's vital because we're facing the most explosive era of road expansion in human history."