Pay heed to water use in climate change mitigation: Experts

Besides cutting greenhouse gas emissions, technology, policies or plans that aim to slow down climate change should also take environmental factors such as water usage into account, say researchers.

A more integrated approach might make some options considerably more attractive than others, said Philip Wallis from Monash University in Australia.

"This integrated analysis significantly changes the attractiveness of some mitigation options, compared to cases where water impacts are not considered," Wallis added.

The researchers considered the example of Australia to show how water usage influences the appeal of certain preferred mitigation options.

The researchers analysed 74 options that were ranked in the influential "Low Carbon Growth Plan for Australia" in 2010, and together could help Australia cut its 2000 emission levels by 25 percent by 2020.

The options varied considerably as to how much water each one uses. Energy efficiency measures were found to reduce water consumption, as do measures in the power sector generally.

Renewable options such as solar thermal power only moderately impact water consumption. Further reductions are possible by tapping into existing power-related water supplies or using air or salt-water cooling.

Wind power, biogas, solar photovoltaics, energy efficiency and operational improvements to existing power sources can reduce water demand by offsetting the water used to cool thermal power generation.

Technologies and locations used for renewable energy should appropriately reflect water constraints, Wallis noted.

"This Australian case shows that mitigation measures that carry water co-benefits, especially energy efficiency, ought to be pursued," he added.

The study appeared in the journal Climatic Change.