Reuters: Efforts to convince rich nations to toughen emissions cuts have failed to make much headway at climate talks in the Thai capital, the U.N. said on Friday. Delegates from about 180 nations are meeting in Bangkok to try to narrow differences on ways to broaden and deepen the fight against climate change. The September 28-October 9 talks are the last major negotiating session before environment ministers meet in Copenhagen to try to seal a tougher global pact to replace the Kyoto …