On behalf of UNESCO, Dr. Shahbaz Khan s presentation focused on the water issue with reference to energy needs of the growing world population.

UNESCO: NATURAL SCIENCES

"Desalination requires a lot of power ... we estimate that about four tonnes of carbon are emitted per million gallons of freshwater produced here, " he says, with reference to the energy-intensive process of removing salt from seawater (see factbox).

CNN: Counting the carbon cost of bringing water to the desert

In Dr Attari's study, for example, the survey provided a reference measure by stating the amount of energy used by a standard light bulb.

ECONOMIST: Energy conservation