Climate change has already caused visible impacts in the United States and poses particular risks to the U.S. agriculture and energy industries, a new government report said on Tuesday.

The report, which lays out the effects of global warming on specific U.S. regions and sectors, calls for quick policy action as the U.S. House of Representatives prepares to vote soon on a bill to reduce U.S. greenhouse gas emissions.

It's not too late to act, said Jane Lubchenco, the administrator of the National Oceanic and Atmospheric Administration, while releasing the report.

Human induced climate change is a reality, not only in remote polar regions (and) in small tropical islands, but every place around the country -- in our own backyards.

The House climate bill aims to reduce carbon emissions 17 percent by 2020 and 83 percent by 2050. Its success is considered crucial to U.S. legitimacy at international talks on climate change in December, but chances of passage in the U.S. Senate are unclear. The United States is the biggest per capita emitter of the climate-warming gas carbon dioxide.

Authors of the report said it was not meant to back a specific policy proposal, but they underscored the consequences of failing to reduce carbon dioxide emissions, which are blamed by scientists for contributing to global warming.

In the agriculture sector, for example, the results of climate change would be largely negative.

Increased heat waves and droughts would affect crop and livestock production while more frequent heavy downpours of rain would reduce crop yields.

Many crops show positive responses to elevated carbon dioxide and low levels of warming, but higher levels of warming often negatively affect growth and yields, the report said.

EFFECTS ON ENERGY

In the energy industry, rising temperatures would constrain energy production while making infrastructure increasingly vulnerable in coastal areas, including New Orleans, which was devastated by a hurricane some four years ago.

Increases in hurricane intensity are likely to cause further disruptions to oil and gas operations in the Gulf, like those experienced in 2005 with Hurricane Katrina and in 2008 with Hurricane Ike, the report said.

The Gulf of Mexico is home to nearly 30 percent of the nation's crude oil production and some 20 percent of its natural gas output.

Climate change would also result in greater demand for cooling energy, the report said, which would lead to significant increases in electricity use and higher peak demand in most regions.

Environmentalists welcomed the report and called on policymakers to heed its warning.

The White House report on climate change is a stark confirmation of what scientists have been saying for years: unless we dramatically curb our emissions, the world will face unprecedented climate disruptions that will lead to drought, flooding, rising seas, food insecurity and mass displacement, environmental group Greenpeace said in a statement.

But it begs the question: are the President and Congress taking the action necessary to avert this crisis?

(Editing by Jackie Frank)

Global warming Climate change Energy