BRUSSELS, Oct. 24 -- Leaders of the European Union (EU) have agreed to cut greenhouse gas emissions by at least 40 percent by 2030 on the basis of 1990 levels.

At an EU summit, leaders also agreed to have at least 27 percent of renewable energy in total energy consumption by 2030, plus an increase of at least 27 percent in energy efficiency, European Council President Herman Van Rompuy said early Friday.

"It sets Europe on an ambitious yet cost-effective climate and energy path. Climate change is one of the biggest challenges of mankind. Ultimately, this is about survival," said Van Rompuy.

He also said the deal would allow the EU "to bring a positive message to the international climate negotiations -- a message of commitment."