21st Conference of the Parties on Climate

UNFCCC COP 21/ CMP 11.  30 Nov – 11 Dec, 2015

Washington (CNN)President Barack Obama on Friday rejected the proposed Keystone XL pipeline, ending the political fight over the Canada-to-Texas project that has gone on for much of his presidency.

A man sunbathes in the midday sun during a heat wave at Glenelg beach on January 13, 2014 in Adelaide, Australia.

Extreme weather events, from droughts to floods and heat waves, are some of the most tangible present day impacts of global warming, and they will take center stage in speeches at the upcoming Paris Climate Summit. Now a new report gives leaders pushing to reduce emissions of global warming pollution, including President Obama, additional ammunition.

The Obama administration rejected the Keystone XL oil pipeline on Friday, handing a major victory to environmentalists after a seven-year review process that gave rise to a grassroots climate activist movement. President Barack Obama announced his decision at a morning news conference in the White House Roosevelt Room, alongside Secretary of State John Kerry and Vice President Joe Biden.

U.N. climate negotiations begin in Paris in less than a month.
Credit: Omarukai/Flickr

Diplomats steeling themselves for a historic round of United Nations climate negotiations remain divided by a handful of stubborn disputes. Discord persists over financial and procedural issues, for example, and over how pollution from farming and deforestation should be addressed alongside energy generation.

The fundamentals of climate science, however, are not among the issues being debated...

The Republican Party could be the single greatest impediment to global efforts to slow climate change. But cracks are forming in the conservative wall of denial.

WASHINGTON (AP) — Americans are hot but not too bothered by global warming...

The world is getting hotter. But a lot of important people aren't "buying in."