L'AQUILA, Italy - Targeting global warming, leaders of the world's richest industrial countries pledged(保证，许诺) Wednesday to seek dramatic cuts in greenhouse gas emissions by 2050 to slow dangerous climate change. They agreed for the first time that worldwide temperatures must not rise more than a few degrees.
However, their goals are nonbinding, and it's far from clear they will be met. The wealthy nations failed to persuade the leaders of big developing countries to promise to cut their own fast-spreading(迅速传播的) pollution, unable to overcome arguments that the well-established industrial giants aren't doing enough in the short term.
President Barack Obama and the leaders of the other wealthy Group of Eight nations agreed that global temperatures should be kept from rising by more than 2 degrees Celsius, or 3.6 degrees Fahrenheit(华氏温度）, in the fight against weather changes caused by mankind.