Europeans started over-exploiting freshwater fish at least 1,000 years ago, according to historical studies that could help manage depleted modern fish stocks worldwide.

Whales teemed in waters off New Zealand in the 19th century and a now almost non-existent cod stock in the Gulf of Maine totalled a huge 70,000 tonnes a year in the mid-19th century, according to historical records.

Power generation from renewable sources such as wind turbines, solar cells and biomass plays a small but important part in satisfying total electricity demand around the world, and is growing at an exponential rate thanks to generous public subsidies and government support.

Australia's government will spend A$4.5 billion (US$3.4 billion) in partnership with private investors to build up to eight commercial power stations testing clean coal and solar technologies, Treasurer Wayne Swan said on Tuesday.

Every household in Britain should by 2020 be able to cut its energy bills and carbon footprint using "smart meters" and handheld devices to control energy use closely, the government said on Monday.

Britain lodged a claim to a large swath of South Atlantic seabed around the Falkland Islands on Monday, setting the stage for a battle with Argentina for control of potentially rich oil and gas reserves in the area.

Energy scarcity has become more serious for the energy-deficient growing economies having insufficient resources to combat the environmental pollution, said former HEC chairman Dr Attaur Rehman in his inaugural speech as chief guest at a three-day international conference.

Wave energy could catch up with commercially more advanced offshore wind power within five years, the head of pioneers Aquamarine Power Ltd told Reuters.

"What it took 25 years to do in the wind industry, we want to do in five years," Chief Executive Officer Martin McAdam said in an interview.

A proposed UK scheme designed to force some 5,000 businesses to cut carbon emissions by reducing their energy consumption gives companies no reason to buy renewable energy, critics said on Friday.

"Businesses need greater incentives to demand increased renewable power in their fuel mix, not less," said Jo Butlin, vice president at UK renewable power supplier Smartest Energy.

The UK government is to launch an environmental study on marine energy projects in England and Wales, paving the way for commercial wave and tidal devices to be deployed.

Three of Europe's biggest utilities bought land to build nuclear power plants in England and Wales Wednesday, in a sale that generated 387 million pounds to retire old reactors the government wants replaced.