The United Nations secretary-general called for a clean energy revolution to avoid a "climate catastrophe" as talks on a global warming pact entered their final week Monday with crunch issues on money and burden-sharing yet to be resolved.
One of them, however, appeared to be untangling as the European Union softened its insistence that countries' targets to limit carbon pollution need to be legally binding, something U.S. negotiators reject because of opposition in the Republican-controlled Congress.
Foreign and environment ministers joined the talks after lower-level negotiators who met last week delivered a draft agreement with multiple options left open.
The Paris conference is the 21st time world governments have met to seek a joint solution to climate change - and is aiming at the most ambitious, long-lasting accord yet.
Fossil fuels still meet about 80 percent of the world's energy demand, though the share of renewable energy including hydro, solar and wind power is growing, particularly in electricity generation.