Montreal revisited - nations gather to discuss ozone hole
Twenty years ago the hole in the ozone layer topped the environmental agenda and the global agreement on how to address the problem - the Montreal Protocol - was heralded as an exemplar of international co-operation.
This week, negotiators from 191 countries have returned to the Canadian city to debate whether to do more, faster to speed the repairs.
While concerns about climate change have now eclipsed the ozone layer in the political arena, the UN has pointed out that by addressing one, the international community can help the other.
"The Montreal Protocol is successfully assisting in the repair and recovery of the ozone layer," said Achim Steiner, executive director of the United Nations Environment Programme.
"The Kyoto Protocol is tackling perhaps the greatest challenge of our generation - climate change. However, what is also emerging in 2007, and emerging with ever greater clarity, is that both treaties are mutually supportive across several key fronts."
Kyoto's clean development mechanism (CDM) has led to the destruction of large volumes of the very potent greenhouse gas HFC-23, a by-product of the production of the coolant HCFC-22, and is currently the only reliable mechanism available to prevent emissions of this gas in the short term, according to a new report to be released in Montreal this week.
"The Kyoto Protocol's CDM is assisting to destroy HFCs," said Mr Steiner.
"Meanwhile, governments here in Montreal look set to back an accelerated freeze and phase-out of HCFCs, with important benefits for the ozone layer and also for climate change.
"This kind of cooperation underlines the importance of the UN and its related environmental agreements, demonstrating in clear and concrete terms how, by combining their strengths, they can more efficiently and cost effectively realize the sustainability goals of our time."