Elected leaders in New York City will propose a suite of laws and other initiatives on Wednesday aimed at reducing energy consumption and related emissions of greenhouse gases by requiring owners of thousands of older buildings to upgrade everything from boilers to light bulbs.

Canadian environmental groups asked regulators on Wednesday to rescind approvals for part of a $13.7 billion expansion of Royal Dutch Shell Plc's oil sands project, alleging the company backed off promises to cut greenhouse gas emissions.

Steps President Barack Obama has taken on climate and clean energy have shown that the United States is getting ready to lead the world in fighting global warming, a White House official said on Tuesday.

South Africa's ANC party, expected to win elections this month, is promising a new energy strategy to tackle power shortages and cut greenhouse gases that account for more than two-fifths of the continent's emissions.

A key pillar of this plan is the likely split of the minerals and energy cabinet portfolio, to remove red tape that critics say is bogging down the ministry's performance.

South Africa's energy minister said on Thursday the country was still in the grip of a major power crisis despite being able to keep the lights on since a series of blackouts early last year.

Voluntary energy savings had failed to meet the required levels, and the country was risking new power cuts, the Minister of Minerals and Energy, Buyelwa Sonjica said in a statement.