Group of Eight (G8) powers failed to overcome US resistance to committing to specific numerical targets to curb global warming but did refer to the goal of some countries of cutting emissions by 50 percent by 2050.

"In terms of targets, we agreed on clear language ... that recognizes that (rises in) CO2 emissions must first be stopped and then followed by substantial reductions," Merkel told reporters at the G8 summit in the Baltic coast resort of Heiligendamm.