Former Vice President of the U.S. Al Gore called Monday for immediate action to stop global warming, calling the phenomenon a "climate crisis" that demands attention from American leaders.

Gore, a Democrat who narrowly lost the 2000 presidential race to George W. Bush, brought to attention the lack of action on global warming by politicians across the ideological spectrum.

|PIC1|"When we make big mistakes in America, it is usually because the people have not been given an honest accounting of the choices before us," Gore said in an hour-long speech at New York University Law School. "It also is often because too many members of both parties who knew better did not have the courage to do better."

Gore has brought considerable attention to the global warming phenomenon, when his documentary film, "An Inconvenient Truth," was released in the UK last week to wide critical praise. The movie has become one of the highest-grossing documentaries worldwide, while a companion book on the topic has become a bestseller.

Thousands of people and numerous Christian organisations are expected to gather in London this November for the 'I Count' climate event to pressure the UK government into taking urgent action on climate change.

The 'I Count' event will be hosted by the Stop Climate Chaos coalition in London's Trafalgar Square from 1pm to 3pm on Saturday 4 November and will also make the call for a radical reduction of worldwide carbon emissions over the next decade.

Later in November, the Queen's Speech could include a landmark bill, which would commit to a Carbon Budget as a way of managing UK greenhouse gas emissions - something environmental and Christian groups like Tearfund have been pushing for.