SINGAPORE — Developed and developing countries continue to haggle over terms of a new pact to limit global warming gases. With only 15 full negotiating days scheduled before a climate change summit convenes in Copenhagen at the end of the year, the next round of negotiations in Bangkok (Sept. 28-Oct. 9) looms as a make-or-break effort.

On two key issues, the parties are poles apart. The panel of scientists and officials advising the United Nations on climate change says industrialized countries need to take the lead by agreeing to cut their greenhouse-gas emissions by as much as 40 percent by 2020. But so far, pledges from Japan and other advanced economies are below these levels.

Meanwhile, their offers of money and technology to help developing countries reduce greenhouse-gas emissions and adapt to climate change are a long way short of the U.N. target. Two recent findings underscore the need for action.