The more I reflect on the 23 impressive years since the signing of the Montreal Protocol, the more I realize what far-reaching lessons it holds for the global environmental agreements of today.

As we close the door on the first decade of the 21st century, the environmental crises that we face today require action beyond even the scale of the world's response to the ozone-depletion emergency in the late 20th century.

As we all know, the ozone layer is a thin layer in the atmosphere that sits about 10-50 km above the Earth. It absorbs most of the harmful ultraviolet radiation from the sun. The discovery of an ozone "hole" in 1985 shocked the world and two years later the Montreal Protocol was signed. Today, almost every country in the world has ratified the agreement.

Along with this year's International Ozone Day, which was on Sept 16, it is worth recalling that the Montreal Protocol is not simply a multilateral global accord designed to eradicate ozone-depleting substances.

In a unique way, the Montreal Protocol brought the global community together to find a way to move forward. Everyone agreed that what happens to the ozone due to the release of chlorofluorocarbon gases (CFC) - which were used in aerosols, refrigerators and are still used in air conditioners - was completely linked to what happens to life on Earth. The industrialized world later provided the incremental financial and technical assistance to developing countries to implement the agreement.

As Mario Molina, who in 1995 won the Nobel Prize in Chemistry for his role in elucidating the CFC threat to the Earth's ozone layer, said: "The Montreal Protocol is widely considered the most successful environmental treaty, phasing out almost 100 ozone-depleting chemicals by 97 percent and placing the ozone layer on the path to recovery by mid-century."

In phasing out the vast majority of ozone-depleting substances, the Montreal Protocol created a whole range of new job opportunities in industrialized and developing countries. Recycling, retrofitting, containment and best practices, in addition to the implementation of energy standards and labeling, are just some of the new activities that were undertaken by industry and governments. These also opened up new vistas for employment.

Enterprises in developing countries also benefited from a wave of technological innovation for upgrading their production lines and deploying the latest energy- and resource-efficient technologies.