The U.N.'s climate chief says talks in 2015 to secure a global warming pact will not fail as they did at the 2009 Copenhagen summit where world leaders, including President Barrack Obama, could not reach an agreement.

Speaking ahead of a climate meeting in Bonn next week, Christiana Figueres told reporters in a teleconference that much had changed, giving her optimism that a global climate pact can be reached in Paris in 2015. Figueres says climate change is worsening and governments have already committed to reaching a deal.

The goal of the talks is to reach a deal involving rich and poor nations that would keep temperatures from rising more than 3.6 degrees Fahrenheit (2 Celsius), compared to pre-industrial times.