U.N. climate panel issuing its gloomiest prediction yet

U.N. to release report on rising sea levels

A new United Nations report that sounds the alarm about the planet's failing health will be released in Monaco later this week. Details have begun to emerge about the effects of global warming on the world's oceans and frozen regions.

The report is expected to reveal that the ice in the Arctic and Antarctic is melting much more quickly than previously thought. It's also expected to say warming is so far advanced that tipping points have been crossed and some of the more severe consequences can no longer be avoided, reports CBS News correspondent Mark Phillips.

Among the cited consequences are rising sea levels that could displace hundreds of millions of people from coastal areas, increased numbers of destructive storms, devastated fish stocks and even reduced supplies of drinking water.

The report is the gloomiest prediction yet by the U.N.'s climate panel. It predicts that if greenhouse gasses are not significantly reduced, the consequences will get even worse.

CBS joins dozens of news organizations in "Covering Climate Now" initiative

As CBS News correspondent Debora Patta reported earlier this month, a group of 300 scientists are spending a year-long expedition in the Arctic to study the effects of climate change. They will sail close to the North Pole, cut the engine and wait for water to freeze around their vessel, before drifting with the ice flow.

"You have seen that in the U.S. at the beginning of this year when the snowstorms and blizzards went down to Florida — that is all driven by climate change in the Arctic and we need to understand that to understand how our extreme weather in the future will look like," said Markus Rex, the expedition leader.

Ahead of the report's release, activists have taken to the streets to demand action on climate change. A group chained themselves to a sailboat and shut down major intersections in Washington, D.C., on Monday. While the demonstrations were mostly peaceful, police made more than two dozen arrests.