nature materials | VOL 10 | MARCH 2011 | www.nature.com/naturematerials 157
editorial
When we think of scarce natural resources,
the availability of oil is the main one that
comes to mind. Indeed, this year has seen
rising oil prices that recovered from a dip to
US$40 per barrel, and for the first time in
two years again have exceeded US$100 per
barrel. Oil is becoming difficult to produce
with rigs being placed at increasingly
challenging locations.
However, what has recently become
clear is that many other key materials are
in danger of becoming unavailable. The key
difference is, however, that oil is a molecule
that is valuable for the energy stored in it,
and not for its carbon and hydrogen atoms.
Many of the scarce materials on the other
hand are valuable because of the chemical
elements they contain.
The group of materials that has been
widely in the news are the rare-earth
elements, many of whose prices have
more than tripled over the past year.
As Alexander King, director of the
Ames Laboratory in Iowa, US, says in
his Interview1, prices will continue to
rise. China, who mines 97% of the global
rare-earth metal supply, now requires a
significant amount of these elements for its
own domestic production. At the same time
global demand is also set to rise, making
price hikes inevitable.
A good example of this problem is that of
the rare-earths neodymium and dysprosium.
Some of the most powerful yet small and
lightweight permanent magnets are made of
neodymium iron boron, mixed with small
quantities of dysprosium to enhance their
operation temperature. These magnets are
used in computer hard drives, in the electro
motors of the increasingly popular hybrid
and electric cars, as well as in wind turbines.
The problem with these rare earths is
not so much that these elements are scarce,
but that the cheap prices of the ores coming
out of China has squeezed any competition
out of the market. The inevitably rising
commodity prices will counter this trend,
and other mines outside China are in the
process of being started again. However,
until these are operational prices will
continue to rise, possibly quite dramatically.
Unfortunately, rare earths are not the
only scarce chemical elements that are of
concern2. Tellurium, which is used in solar
cells, is mined along with the commercially
far more attractive copper. As King also
points out in his Interview, at present it is
not commercially attractive to produce small
quantities of tellurium in favour of the much
larger copper market, in particular as copper
prices have also risen by more than 50% last
year. Unless of course tellurium prices follow
that trend and adjust accordingly.
There are two reasons for chemical
elements to become scarce. Some, like
tellurium, are simply not that abundant
anywhere in the Earth’s crust, whereas
others are found in only a few places,
which might create political issues for their
supply. China’s dominance on rare earths
falls into that category, or Bolivia’s and
Chile’s vast resources of lithium, which is
used for rechargeable batteries. And the
known global reserves of niobium, which
is abundant and used for steels and other
alloys, are almost entirely located in Brazil.
What are the lessons from these projected
shortages? Certainly that we need to be
more proactive. One of the first countries
to realize such upcoming shortages of
elements was Japan — a country without
such natural resources and therefore highly
dependent on their availability. In his
Commentary, Eiichi Nakamura from the
Chemistry Department at the University of
Tokyo describes some of Japan’s initiatives to
combat the scarcity of resources2.
We need to recognize that this is an issue
that affects a broad range of technologies.
The rare earths alone are important in areas
that span from clean energy to lasers and
telecommunications, where erbium is a key
element for optical fibre technology.
Once critical areas are identified, we
need to manage our resources better. In
some instances it could simply mean to
intensify mining. For scarce elements it
may also mean to better manage their
consumption. Crucial is to reuse and recycle
where possible. The use of rare earths in
electronic gadgets has risen so much that
their concentration in computers is actually
higher than that in mines. It pays to recycle.
Eventually, market forces will of course
even out such imbalances in supply and
demand. However, in the short-term price
hikes and supply problems can lead to
considerable distortions of these markets.
In the long-term, we need to be more aware
of the issue and be more careful in the
managing of our natural resources.
And this is not only for the benefit of
securing technological progress. The supply
of phosphorus, which as an element is
actually not very rare, comes entirely from
mining, with large reserves in the Middle
East and in China. Phosphorus is not only
important for example for detergents, but
also as a fertilizer for plants. And although
at present there is no fundamental shortage
of phosphorus, with the continuing growth
of the human population and the advance of
biofuels resources might quickly be running
out. With our own bodies being crucially
dependent on phosphorus it is to be hoped
that by then we are better equipped in
managing shortages of chemical elements. ❐
References
1. Nature Mater. 10, 162–163 (2011).
2. http://minerals.usgs.gov/minerals/pubs/commodity/
3. Nakamura, E. Nature Mater. 10, 158–161 (2011).
In a special issue this month we explore the challenges caused by supply shortages of several important
chemical elements.
Elements in short supply
Rare-earth magnets being recycled at Hitachi.
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