March 2020

The MEDEA Program; Human Migrations to the Americas, 2019 Flooding of Venice; Citizen Science; Using Data in Teaching; and More…

SAND A Resource That’s Washing Away

By Cheryl Lyn Dybas

Sand. It’s under our feet when we walk on

a beach, and is in every house and road,

wine glass and cellphone, brick and can

of paint. But we rarely spare a thought for

this seemingly endless resource.

That needs to change, according to

a 2019 report by the United Nations

Environment Programme (UNEP): Sand

and Sustainability: Finding New Solutions

for Environmental Governance of Global

Sand Resources.

After water, sand is the second most

traded resource by volume worldwide.

Sand and gravel together are the number

one solid material mined globally, accord-

ing to an earlier (2014) UNEP report: Sand,

Rarer than One Thinks.

Researchers are finding that even an

apparently ubiquitous substance like sand

cannot keep up with current demand.

Around the world, 40 to 50 billion tons of

sand and gravel are used every year, the

equivalent of a 35 m high by 35 m wide

wall circling the equator.

“Formed by slow erosive processes,

sand and gravel are now being extracted

at a rate far greater than their renewal,”

states the 2014 UN report. “That’s hav-

ing a major impact on rivers, deltas, and

marine ecosystems, resulting in a loss of

Photo credit: Ilya Raskin

land through river or coastal erosion, low-

ering of the water table, and decreases in

the [downstream] sediment supply.”

Despite the colossal quantities of sand

being removed, our increasing depen-

dence on it, and the impact its extraction

has on the environment, the situation has

been largely ignored by policy makers and

is almost unknown to the public.

“Sand is used by everyone,” says

Pascal Peduzzi, director of the Global

Resources Information Database-Geneva

at UN Environment. Peduzzi first raised

the issue of dwindling sand supplies.

“We are now working with stakeholders

at every level, hoping to find sustainable

solutions,” he says.

SHIFTING SANDS

Shifting sand consumption patterns, grow-

ing human populations, and increasing

urbanization and infrastructure devel-

opment have increased the demand for

sand threefold over the last two decades.

At the same time, damming and extraction

have slowed sediment delivery from rivers

to coastal areas, leading to reduced sand

deposits in river deltas and accelerated

beach erosion.

“We’re spending our sand ‘budget’

faster than it’s being produced,” says

Joyce Msuya, deputy executive director

of UNEP. “We now need 50 billion tons

per year, an average of 18 kilograms per

person per day. These expectations can-

not be met without improved governance

of global sand resources. We can better

manage this critical resource, and demon-

strate that infrastructure and nature can

go hand-in-hand.”

Most sand goes into the production of

concrete—made of sand, gravel, water,

and cement. Sand is also used to replen-

ish retreating beaches and extend territo-

ries by constructing artificial islands, such

as The World in Dubai, or filling in coastal

areas like those surrounding Singapore.

Until recently, sand was extracted from

land quarries and riverbeds. A result of the

decline of inland sand resources, a shift to

marine and coastal sand mining has taken

place. Now sand mining from marine envi-

ronments is increasing significantly.

Sand extraction from fragile marine eco-

systems may destroy local biodiversity.

And the demand for sand may lead to ille-

gal sand extraction. “Sand mafias” in India,

for example, threaten communities and

their livelihoods and leave environmental

protection efforts at risk.

RIPPLE MARKS: THE STORY BEHIND THE STORY

Oceanography | Vol.33, No.1

Made with Publuu - flipbook maker