Cancún, Mexico (BBN)- The United Nations Climate Change Conference has opened in Cancún, Mexico, with the world body’s top official on the issue calling for a balanced and concrete outcome to meet one of today’s biggest challenges.

“You are gathered in Cancún to weave together the elements of a solid response to climate change, using both reason and creativity as your tools,” Christiana Figueres, Executive Director of the UN Framework Convention on Climate Change (UNFCCC), told the gathering on Monday.

The UNFCCC is an international treaty which considers what can be done to reduce global warming and to cope with whatever temperature increases are inevitable. Some countries have approved an addition to the treaty, the Kyoto Protocol, which has more powerful and legally binding measures.

The meeting is taking place just days after the UN World Meteorological Organization (WMO) found that concentrations of greenhouse gases in the atmosphere have today reached their highest level since pre-industrial times.

Ms. Figueres said a solid outcome in Cancún is urgent given the WMO’s findings as well as because the poorest and most vulnerable need predictable and sufficient assistance to face a serious problem that they did not cause.

“Looking at what you have achieved over the past months, I am convinced that you can compromise to find your way to a concrete outcome in Cancún,” she added. “That outcome needs to be both firm and dependable and have a dedicated follow-on process for future work.”

Ms. Figueres also highlighted a number of “politically charged” issues that need to be tackled, including the need to avoid a gap after the first commitment period of the Kyoto Protocol ends in 2012 and the importance of having clarity on the continuation of the Protocol.

BBN/SI/AD-30Nov10-11:59 am (BST)