The window of opportunity to preserve the Earth's natural capital is diminishing rapidly, UN Secretary-General Ban Ki-moon said on Wednesday, highlighting the need for improved international governance to close the gap between aspirations for environmental sustainability and real-life achievements.

"Coherent and effective international environmental governance architecture can provide a foundation for human well-being for generations to come. I urge you to be bold and creative in putting forward new ideas," the secretary-general said in a message delivered on his behalf to a special session of the UN Environment Programme (UNEP) Governing Council/Global Ministerial Environment Forum in Bali, Indonesia.

The meeting is being attended by some 1,000 participants from 130 countries, including nearly 100 environmental affairs ministers.

Ban warned participants that as consumption grows and climate change gathers pace, they risk reversing many of the gains that have been made towards the Millennium Development Goals (MDGs) that world leaders pledged to achieve by 2015. Among the targets contained within "MDG 7" is to integrate the principles of sustainable development into country policies and programs and reverse the loss of environmental resources.

The secretary-general singled out the Montreal Protocol to the Vienna Convention for the Protection of the Ozone Layer -- designed to protect the ozone layer by phasing out the production of a number of substances believed to be responsible for ozone depletion -- as a "practical example" of how to unify different national responsibilities.

"Its combination of political will, legal teeth, adequate funding and private sector collaboration is a powerful mix. Its lessons can be applied to other areas that demand urgent remedies, including climate change," he said.

He also commended the Copenhagen climate conference as a " significant step forward" in a number of areas, including the creation of a "two-degree target," which refers to the goal of keeping the global mean temperature from rising more than 2 degrees Celsius.

Ban also urged countries to continue negotiations under the UN Framework Convention on Climate Change (UNFCCC), despite criticism by climate skeptics fueled by leaked e-mails from the University of East Anglia's Climatic Research Unit that raised questions about the quality of research on some specific topics connected to climate change.

"I urge you to reject the last-ditch attempts by climate skeptics to derail your negotiations by exaggerating shortcomings in the IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report. Tell the world that you unanimously agree that climate change is a clear and present danger," said Ban.

The secretary-general also highlighted the UN's continuing role to support intergovernmental processes, such as the creation of the High-level Advisory Group on Climate Change Financing and the upcoming launch of the High-level Panel on Global Sustainability.