The NYT has an article about the horrible environmental damage done by the mining of rare earth elements used in the manufacture of "green tech":
Some of the greenest technologies of the age, from electric cars to efficient light bulbs to very large wind turbines, are made possible by an unusual group of elements called rare earths. The world’s dependence on these substances is rising fast.
Just one problem: These elements come almost entirely from China, from some of the most environmentally damaging mines in the country, in an industry dominated by criminal gangs.
In the past I've discussed ecologically degrading components used in cheap solar panels.