BRUSSELS, Aug 7 (Reuters) - The European Commission urged the world on Tuesday to stick with a goal of limiting climate change to a maximum temperature rise of 2 degrees Celsius (3.6 F) after Washington said the target could not be guaranteed.
"World leaders pledged in Copenhagen to stay below the 2C temperature increase. What leaders promised must now be delivered," Commission spokesman Isaac Valero-Ladron said of a 2009 climate summit in the Danish capital.
Almost 200 nations including the United States backed the target that rises in average world temperatures should be below 2C above pre-industrial times, viewed as a threshold for dangerous changes in the Earth's climate.
Global average temperatures have already risen by 0.8C, blamed by a U.N. panel of climate scientists on increasing greenhouse gases, mainly from burning fossil fuels.
Todd Stern, the U.S. climate change envoy, said in an Aug. 2 speech that Washington wanted a more flexible approach to a new U.N. agreement, due to be adopted in 2015, so that it could be modified over time such as to take account of new technologies.
"This kind of flexible, evolving legal agreement cannot guarantee that we meet a 2 degree goal, but insisting on a structure that would guarantee such a goal will only lead to deadlock," he said.
The Copenhagen summit failed to produce a new U.N. deal to limit climate change and the revised target is for talks to end with a global pact in 2015 that would enter into force in 2020.
The European Union has long insisted on the 2C maximum, agreed by U.S. President Barack Obama at a G8 summit in 2009, viewing it as a trigger for dangerous changes such as more heatwaves, floods and rising sea levels.
"Consolidated science continues to remind us of the dire consequences of going beyond such a temperature increase," Valero-Ladron said.
But the 2C target is slipping away as emissions rise.
A Climate Action Tracker by scientists in May estimated that the world is headed for a rise of about 3.5 degrees Celsius, based on existing promises for curbs in planet-warming greenhouse gas emissions.
Emissions of carbon dioxide, the main greenhouse gas, rose 3.1 percent in 2011 to a record high and the decade ended in 2010 was the warmest, U.N. data showed.
Stern said it was better to start with actions that could spur innovation and to build political support. China, the United States, the European Union, India and Russia are the main emitters of greenhouse gases.
(Reporting By Barbara Lewis and Alister Doyle in Oslo; Editing by Janet Lawrence)