The Chilean miners are world-famous, as they are unlikely survivors – after being feared dead for two weeks, following the collapse of a mining tunnel. Luck is very rare at such depths. Every year thousands die in mining accidents worldwide, most of them in Chinese mines.

Although official statistics are scarce, the International Federation of Chemical, Energy, Mine and General Workers’ Unions [didn’t Marx have a more effective phrase to bundle such a big group?] (ICEM) estimates the total number of annual mining casualties is as high as 12,000.

Are risks inherent to such deep ventures? Daniel Litvin, Director of British consultancy Critical Resource, thinks the world’s race for energy resources plays a role, with demand for coal rising ever faster, despite environmental concerns over its high CO2 emissions*.

“As the energy race accelerates, safety gets neglected – with smaller companies stepping into the mining industry,” he says in a short interview with the BBC World Service radio. The smaller companies want to make a quick profit – and may use inferior safety standards in their mines.

“But the BP oil spill accident shows lapses also happen with the big energy companies.”

And it’s not just energy resources that see a mining industry in a hurry. It goes for anything finite that cannot be missed in the economic system. Like rare earths.

[*Ever wondered why coal is so much worse than natural gas? Ignore the chemical impurities (don't do that when considering non-CO2 coal pollution) and a coal molecule would be graphite: pure carbon - with every carbon atom attached to 4 other carbon atoms (the odd exception is graphene). When you burn it, every carbon atom oxidises to CO2. Natural gas is (again, impurities ignored) methane, CH4. When you burn one molecule of that, you only burn one atom of carbon, indeed forming CO2. But chemically speaking you also burn four hydrogen atoms. These form innocent water when oxidised - also adding a little extra energetic value to the process. So, per Joule, natural gas is less CO2 intensive than coal. Oil is somewhere in between: a sticky carbohydrate, with roughly equal amounts of Cs and Hs.]

(c) Rolf Schuttenhelm | www.bitsofscience.org