National targets have to be implemented through domestic policies which encourage businesses to invest in clean products and processes, and discourage them from investing in carbon-intensive products and processes.

ECONOMIST: The Copenhagen Summit

Most are produced in huge, ultra-clean factories using batch processes similar to those for making silicon chips.

ECONOMIST: Electronic screens as thin as paper are coming soon

Holography and optical correlation are both inherently analogue processes that can degrade the clean 1s and 0s required in a digital system.

ECONOMIST: Optical recognition