The UN's top climate official said Sunday she expects governments to make a long-delayed decision on whether industrial countries should make further commitments to reduce emissions of climate-changing greenhouse gases. Amid fresh warnings of climate-related disasters in the future, delegates from about 190 countries were gathering in Durban for a two-week conference beginning Monday. They hope to break deadlocks on how to curb emissions of carbon dioxide and other pollutants. Christiana Figueres, head of the UN climate secretariat, said the stakes for the negotiations are high, underscored by new scientific studies. Under discussion was “nothing short of the most compelling energy, industrial, behavioral revolution that humanity has ever seen,” she said. Hopes were scrapped for an overall treaty governing global carbon emissions after the collapse of talks at a climate summit in Copenhagen two years ago.