The Montreal Protocol has had a direct effect on climate change, a largely negative one
One of the outcomes of the Montreal protocols has directly affected climate change, and contributed to it to some degree. The Montreal Protocol effectively replaced the industrial use of CFC gases with HFC’s that do not contribute to atmospheric ozone loss. HFC’s on the other hand are a greenhouse gas, and there use helps infra-red radiation say within the Earth's atmosphere, slowly raising the atmosphere's ambient temperature.
The Montreal protocol was an international treaty to protect the Earth's ozone layer and it ultimately banned the use of CFC’s in refrigeration, air conditioning and propellant systems, ultimately replacing many of them with HFC’s. CFC’s degraded in the atmosphere, the spare chlorine atom bonding with ionic oxygen leading to less O3 (ozone) developing. The Montreal Protocol may have proved to be effective policy for what it set out to do, but it fed into the much bigger, far reaching and potentially catastrophic issue of global warming. The Montreal protocol remains a narrow solution to a narrow problem, climate change calls for a much more in-depth change to industry, attitudes and society as a whole to be a success and save human life as we know it.