WASHINGTON (AP) — Critics are assailing the National Climate Assessment out today as "alarmist."

Some fossil energy groups, conservative think tanks and Republican senators immediately attacked the 840-page report, which the White House is highlighting as it tries to jump-start efforts to curb heat-trapping gases.

Senate Republican leader Mitch McConnell of Kentucky said President Barack Obama was likely to, quote, "use the platform to renew his call for a national energy tax."

Republican Sen. David Vitter of Louisiana said the report was supposed to be scientific -- but he says it's "more of a political one used to justify government overreach."

The report concludes that global warming is already causing violent storms and other weather hazards for the United States. And it says the effects will "become increasingly disruptive across the nation throughout this century and beyond."

The report is the third edition of a congressional mandated study. More than 250 scientists and government officials started writing the report in 2012. A draft was released in January 2013, but this version has been reviewed by more scientists and has had public comment.

The National Academy of Science reviewed the report twice and called it "reasonable."

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