Main Issue

The ozone layer is mainly found in the lower portion of the stratosphere, about 20 to 30 km (12 to 19 miles) above the earth, though the thickness varies seasonally and geographically. The ozone layer protects living things from harmful ultraviolet rays from the sun; without the protection of the ozone layer, millions of people would develop skin cancer and weakened immune systems.

Concern about a depleting ozone layer dates back to the 1970s. Scientists then discovered a “hole” in the ozone layer over the Antarctic in the 1980s. Initially, concern for the ozone focused on chemicals known as chlorofluorocarbons (CFCs). Later, halons, carbon tetrachloride (CTC), methyl bromide and hydro chlorofluorocarbons (HCFCs) were targeted.

In 1985, countries adopted the Vienna Convention for the Protection of the Ozone Layer. Two years later, they adopted the Montreal Protocol on Substances that Deplete the Ozone Layer. This protocol has its own financial mechanism, the Multilateral Fund, which helps developing countries comply with the protocol.

With 197 nations party to the accord, the Montreal Protocol is the only universally ratified treaty in United Nations’ history. To date, it has helped reduce more than 97 percent of all global consumption and production of controlled ozone-depleting substances (ODS). As a result, the levels of these substances in the atmosphere have begun to fall.

The same chemicals that harm the ozone also warm the climate. Between 1989-2013, the Montreal Protocol prevented the emissions of 5.6 billion tonnes CO2 equivalent annually. In 2016, the Parties agreed to regulate hydroflurocarbons (HFCs) under the Montreal Protocol. While HFCs have largely replaced CFC and HCFCs and do not harm the ozone layer, they are powerful greenhouse gases. Controlling the uses of HFCs will effectively prevent a .5 °C increase in global temperature.

What We Do

The GEF is not formally linked to the Montreal Protocol but actively support its implementation. Under the terms of the protocol, countries with economies in transition were not eligible for multilateral funding. The GEF stepped in to fill the gap. The GEF helps the Russian Federation and nations in Eastern Europe and Central Asia to phase out their use of ozone-destroying chemicals under the terms of the Montreal Protocol. 

The GEF focuses on three activities:

  • Phase out use and production of CFCs, halons, and CTC.
  • Support efforts in a number of these countries to phase out methyl bromide completely.
  • Support countries in phasing out HCFCs.


By 2012, the GEF had helped 18 economies in transition to phase out ozone-depleting substances under the Montreal Protocol. The GEF has invested $235 million in 29 projects that leveraged another $247 million from our partners and resulted in the phaseout of 29,000 tons of ozone depleting potential.

Through the Montreal Protocol, total global consumption of ozone-depleting substances (ODS) has dropped by more than 90 percent compared to a business-as-usual approach. The GEF has helped decrease consumption and production of CFCs in countries with economies in transition. But more work is needed to address other substances, in particular methyl bromide and HCFCs. 

More than 99 percent of ODS have been phased out by the Montreal Protocol over the last 30 years, and the ozone layer is on track to recover by mid-century. Up to 2 million cases of skin cancer may be prevented globally each year by 2030. Importantly, more than 135 billion tonnes of carbon dioxide equivalent emissions have been averted, making the Montreal Protocol an important force to combat climate change.

Looking Ahead

The GEF has responded to new chemicals conventions and the movement towards integration and synergies among the conventions by evolving its strategy to accommodate these transitions. GEF support has moved from separate Chemicals Focal Areas (ODS and Persistent Organic Pollutants) to now having one, fully integrated Chemicals and Waste Focal Area, including POPs, Mercury, ODS, and the Strategic Approach to International Chemicals Management.

The Chemicals and Waste Focal Area will support the reduction of POPs that are controlled by the Stockholm Convention on Persistent Organic pollutants, mercury and mercury compounds that are controlled by the Minamata Convention on Mercury, Ozone Depleting Substances and other chemicals controlled by the Montreal Protocol on Substances that deplete the Ozone Layer, lead in paints, chemicals of global concern in the supply chain of commercial and domestic products and highly hazardous pesticides that enter the global food supply.

A fully integrated focal area that is better aligned with sectoral investments in countries to address pollution, agriculture, and industrial efficiency can better attract the private sector and link to efforts on increasing environmental sustainability in these sectors, since the actions will be based on sectors rather than targeting a single chemical.