Negotiators from nearly 180 countries are meeting this week in Barcelona to narrow their differences over issues regarding climate change before a key December summit in Copenhagen.
Climate change negotiators are trying to come up with a workable draft document to replace the 1997 Kyoto Protocol. Countries will be discussing that draft - and hopefully coming to an agreement - at a summit in Copenhagen next month. But reaching a deal will not be easy.
Even now, after months of talks, negotiators are still wrangling over a raft of competing proposals. A key question is whether to set binding targets for developing countries to reduce their levels of carbon dioxide emissions. The United States in particular, wants legally binding pledges for the fastest growing countries in this group - such as China and India.
The United Nations, by contrast, has suggested that only richer nations commit themselves to targeted greenhouse gas reductions. Poorer nations could instead agree to adopt green energy and other measures to limit emission growth.
A number of environmental activists doubt the Copenhagen summit will achieve binding emission reduction targets. The environmental group Greenpeace unfurled a banner on top of a key Barcelona landmark - the Sagrada Familia basilica - urging world leaders to act.
Joseph Zacune, international climate change negotiator for the NGO Friends of the Earth, is also pessimistic about Copenhagen. Zacune is attending the Barcelona meeting.
"The trajectory is very negative. It's paving the way for us to see either a weak and damaging deal in Copenhagen or a delayed, weak and damaging deal later in the year, in 2010," he said.
The talks come just days after European Union leaders agreed that richer nations should pay tens of billions of dollars to help poorer ones adapt to climate change. But the European Union did not set an amount for its own contribution - and European Commission President Jose Manuel Barroso said the bloc was awaiting action from others.
"Our offers are not a blank check. We are ready to act if our partners to deliver," he said.
Meanwhile, the French government is floating a proposal for rich countries to fund renewable energy projects in the world's poorest countries. But Zacune of Friends of the Earth says he is again waiting for specific funding commitments.