Sand, a global sustainability challenge: UN report

• The UNEP has released a report, Sand and Sustainability: Finding new solutions for environmental governance of global sand resources.
• It highlights a problem that has largely stayed under the radar: sand consumption globally has been increasing and we are extracting it at rates exceeding natural replenishment rates.

Sand Mining

• Sand and gravel are the second largest natural resources extracted and traded by volume after water, but among the least regulated.
• Sand is created by slow geological processes, and its distribution is not even.
• Desert sand, available in plenty, is not suited for construction use because it is wind-smoothed, and therefore non-adherent.
• While 85% to 90% of global sand demand is met from quarries, and sand and gravel pits, the 10% to 15% extracted from rivers and sea shores is a severe concern due the environmental and social impacts.
• Aggregates (a term for crushed rock, sand and gravels used in construction materials) are necessary for building the infrastructure the world needs, especially developing countries bringing their populations out of poverty.
• Quoting studies, the report estimates that a 40-50 billion tonne of crushed rock, sand and gravel is extracted from quarries, pits, rivers, coastlines and the marine environment each year.
• The construction industry consumes over half of this, and will consume even more in the future.

Hazards of excessive mining

• Their extraction often results in river and coastal erosion and threats to freshwater and marine fisheries and aquatic ecosystems, instability of river banks leading to increased flooding, and lowering of ground water levels.
• The report notes that China and India head the list of critical hotspots for sand extraction impacts in rivers, lakes and on coastlines.
• Most large rivers of the world have lost between half and 95% of their natural sand and gravel delivery to ocean the report says.
• The damming of rivers for hydro-electricity production or irrigation is reducing the amount of sediment flowing downstream.
• This broken replenishment system exacerbates pressures on beaches already threatened by sea level rise and intensity of storm-waves induced by climate change, as well as coastal developments.
• There are also indirect consequences, like loss of local livelihoods — an ironic example is that construction in tourist destinations can lead to depletion of natural sand in the area, thereby making those very places unattractive — and safety risks for workers where the industry is not regulated.

China and India: Leading in global infrastructure

• China increased its concrete use by 540% in the last 20 years, exceeding the use of all the other countries combined.
• Even as domestic consumption rates begin to stabilize, China overseas investment in infrastructure development through the Belt and Road Initiative will drive demand for aggregates in approximately 70 countries.
• Furthermore, domestic demand in India is expected to drive strong future growth in Asia.

India leads in reusing

• The alternative substitute materials the report points to, are several from India, including oil palm shell, waste foundry sand, crushed tiles, granite powder, mine waste, bottom ash, and discarded rubber.
• It also cites the use in India of non-toxic municipal waste in road-building.

Way Forward

• The report suggests better spatial planning and reducing unnecessary construction — including speculative projects or those being done mainly for prestige — thereby making more efficient use of aggregates.
• It calls for investing in infrastructure maintenance and retrofitting rather than the demolish and rebuild cycle, embracing alternative design and construction methods, even avoiding use of cement and concrete where possible, and using green infrastructure.
• The report concludes with a call for large-scale multipronged actions from global to local levels, involving public, private and civil society organisations.
• This will mean building consensus, defining what success would look like, and reconciling policies and standards with sand availability, development imperatives and standards and enforcement realities.