Monreal ProtocolOn 16 September 2007 we commemorated the 20th anniversary of the signing of the Montreal Protocol, a groundbreaking international agreement that curbed and eventually reversed the thinning of the ozone layer, and ushered in a new era of environmental responsibility. By any measure, the Protocol has been a resounding success. Its 191 signatories have together phased out more than 95% of ozone-depleting substances, and we expect the Earth's protective ozone layer to return to its pre-1980 levels no later than 2075 Monreal ProtocolOn 16 September 2007 we commemorated the 20th anniversary of the signing of the Montreal Protocol, a groundbreaking international agreement that curbed and eventually reversed the thinning of the ozone layer, and ushered in a new era of environmental responsibility. By any measure, the Protocol has been a resounding success. Its 191 signatories have together phased out more than 95% of ozone-depleting substances, and we expect the Earth's protective ozone layer to return to its pre-1980 levels no later than 2075

Monreal Protocol On 16 September 2007 we commemorated the 20th anniversary of the signing of the Montreal Protocol, a groundbreaking international agreement that curbed and eventually reversed the thinning of the ozone layer, and ushered in a new era of environmental responsibility. By any measure, the Protocol has been a resounding success. Its 191 signatories have together phased out more than 95% of ozone-depleting substances, and we expect the Earth's protective ozone layer to return to its pre-1980 levels no later than 2075.

I take pride in having played a very small part in that success: As a member of the Dutch Parliament, I helped ratify the Protocol. At the time,
many had questions about its chances for success. Would it be possible to persuade people to forsake useful household and personal goods-to change their everyday habits--in the interest of preserving an invisible chemical layer miles above the highest clouds in the sky? Could governments, communities and industries adapt in the name of the environment?

As it turns out, they could, and they have-very effectively. The Montreal Protocol, the first legally binding international environmental agreement, brought about a remarkable transformation. It changed human behavior world-wide, and in doing so changed-indeed, dramatically improved-the condition of the environment. Today, we stand at an even more crucial environmental crossroads. Climate change broadly threatens human progress, most immediately and seriously in the developing world. Starting next week in New York, at Secretary-General Ban Ki-moon's high-level climate-change meeting, and continuing through to the Conference of the Parties in Bali later this year, world leaders will seek to agree on a successor treaty to the Kyoto Protocol-to secure the multilateral agreement that will enable us to meaningfully address the climate challenge in the years ahead. Twenty years after its inception, the Montreal Protocol is thriving proof that the international community can cooperatively take on shared environmental challenges.

One of the most notable aspects of Montreal's success is its engagement of both the developed and developing worlds in reducing ozone-depleting substances. Because poor and vulnerable communities often bear the highest costs of environmental degradation, we at the United Nations Development Programme-with the financial help of the Multilateral Fund, the Protocol's implementation fund-have helped more than 100 countries phase out over 63,000 tonnes of ozone-depleting substances. In India, for example, we helped 80 small and medium-size businesses cut out 290 metric tonnes of ozone-depleting chlorofluorocarbon-11 (CFC-11) from the manufacture of polyurethane insulation products. The government of Brazil, meanwhile, has finalized a national phase-out plan for getting rid of CFCs three years ahead of time, valued at US$ 27 million.

Farmers in Malawi have taken 185 tonnes of ozone-depleting methyl bromide out of use. The nation's government, working with UNDP, supported the production of materials for a cost-effective alternative to methyl bromide. The project's outreach activities in rural areas offered an added bonus at the community level: HIV/AIDS education and awareness-building by the Malawi National AIDS Commission.

The Protocol has done its share in mitigating climate change, too. Many ozone- depleting substances are also greenhouse gases; their elimination serves to protect not only the ozone layer but also the global climate.

Twenty years after the signing of the Protocol, at the mid-point of the drive to achieve the Millennium Development Goals, the outcomes of Montreal demonstrate how multilateral cooperation can improve the environment and the lives of people who depend on it. As the international community gears up to determine our post-Kyoto course we need the same cooperative spirit, ambitious intent, and inclusive approach of the Montreal Protocol. Most of all the international community needs to recognize that the poor are the most vulnerable to the impacts of climate change, and that we do not need to compromise economic growth or development goals to reduce emissions. With this recognition, and a commitment to change, we might be able to repeat the success of Montreal.

Ad Melkert is UN Under-Secretary General and Associate Administrator of the United Nations Development Programme. He was a Dutch Member of Parliament when the Montreal Protocol was ratified in 1987.