Envoys from more than 190 nations worked through the night at United Nations global-warming talks in Doha to settle differences on fossil-fuel emissions and climate aid, paving the way to a new treaty by 2015. (..) With the talks due to conclude today, industrial and developing nations remained divided about $100 billion in financial aid, an insurance fund for climate disasters and the principle of which countries should shoulder the burden of shifting the world away from oil, coal and natural gas.