Climate change 'here now', US report says

The report is the first issued since Barack Obama became President and is seen as the strongest to come out of the US.

A lead author of the report, Dr Jerry Melillo, says climate change is fact.

"It is clear that climate change is happening now. The observed climate changes we report are not opinions to be debated. They are facts to be dealt with," he said.

The nearly 200-page document is a joint venture between the White House and 13 federal agencies.

Mr Obama's chief science adviser, John Holdren, says action must be taken.

"Action needs to include both measures to reduce the emissions of heat-trapping pollution that are driving this problem and measures to adapt to the part of climate change we can't avoid," he said.

Data collected

The report brings together years of scientific research and updates it with new data, painting a bleaker picture of global warming in the United States than has been done before.

It reveals that the average temperature in the US has risen 2 degrees Fahrenheit over the past 50 years,and might rise by up to 11 degrees Fahrenheit by the year 2100.

It warns the number of deaths from heat waves could double in Los Angeles and quadruple
in Chicago if emissions are not reduced.

Sea levels are also expected to rise, with the area near New York City one of the worst hit.

The National Oceanic and Atmospheric Administration's Jane Lubchenco says humans are to blame.

"We're also reporting today with greater confidence than ever before that human activities
are the main cause of the changes we see underway," she said.

"I really believe this report is a game changer, I think that much of the foot dragging in addressing climate change is a reflection of the perception that climate change is way down the road, it's in the future.