Even more voracious than the consumption of finite reserves of fossil fuel, the mining of sand and gravel represents a looming tragedy of enormous proportions, according to a group of prominent scientists.
In an article in the journal Science, researchers including Jianguo Liu, who holds the Rachel Carson Chair in Sustainability at Michigan State University in the US, warn that sand mining is “an emerging issue with major sociopolitical, economic, and environmental implications.”
Used extensively in building, glass-making, road construction and electronics, legally and otherwise, sand and gravel are now the most extracted resources in the world, outstripping even oil and biomass.
In the past 110 years, the amount of sand used in construction has increased 23-fold. Sand accounts for 79% of the primary material inputs for buildings and transport infrastructure, with demand in 2010 alone topping out at 21 gigatonnes.
As a business proposition, sand is comparatively cheap to extract and demand is constantly increasing, making it an attractive target for incorporated and ad hoc mining companies.
Mining ventures – many under arrangements that are not predicated on environmental assessments, pollution control or rehabilitation obligations – are being blamed for widespread coastal erosion, degradation of river systems and habitat destruction. In some cases, pits left over after mining and filled with standing water are thought to be exacerbating public health emergencies by providing additional breeding areas for mosquitoes.
The universality and ubiquity of sand deposits, write Liu and his colleagues, means that the problems associated with its extraction are also global.
“As a result, it is a driver of biodiversity loss that threatens species on the verge of extinc¬tion — such as the Ganges river dolphin — as well as newly discovered species, such as the São Paulo marsh antwren, found in iso¬lated marshes of southeast Brazil that have been heavily degraded by sand mining,” they write.
The damage caused by uncontrolled demand, the authors add, is significantly exacerbated by the fact that in most parts of the world sand is considered a “common resource” – easy to reach and prohibitively expensive to regulate.
As a result, mining is often unfettered, the miners themselves in some places underpaid and exploited, and effective control of the resource determined by influence and power – legitimate or otherwise.
The negative social and political impact, the authors note, tends to be felt among poorer communities near, or downstream from, sand mining operations. This, they write, has “important impli¬cations for environmental justice”.
“The degra¬dation brought about or reinforced through sand extraction places heavy burdens on local populations, especially on farmers, fishers, and those—typically women—fetching water for households. People from these popula¬tions may become environmental refugees, as has already happened in Sri Lanka and the Mekong Delta,” they add.
The article concludes by observing that there has been little in-depth research into the environmental, social and political effects of sand mining, and calls for urgent action to rectify this.
“With increased attention to the complex linkages of sand scarcity, our global community can begin to understand how to use sand more sustainably and avert a trag¬edy of the sand commons,” the authors write.