There's no free lunch in clean energy

Crucial green technologies, including solar panels, wind turbines and electric-vehicle batteries, require increasing amounts of metals, such as lithium, copper, nickel, cobalt, manganese and rare-earth elements. According to US cybersecurity company Mandiant, pr°China agents have even posed online as local US activists in attempts to spark protests over rare-earth mines. [...]there will be limits to such changes in lower-density areas, including much of the United States. [...]with around 775 million people worldwide unable to access electricity, energy conservation alone will not suffice to meet basic sustainable-development targets.