News last week from NASA regarding the hole in the Ozone layer:
For those of you who don’t remember the back history, or why everyone makes a big deal about the ozone layer: it’s a critical layer of Earth’s atmosphere that was severely damaged during the 1970’s and 1980’s when ozone depleting chemicals became widespread around the world and began to build up in the atmosphere. The image below – from NASA – shows the progression for that period of time.
The Montreal Protocol – which entered into force in 1989 but was most recently revisted 1993 – has been hailed as not only the most successful international environmental treaty, but one of the most successful international agreements of all time. After scientists proved definitively the link between halogenated hydrocarbons and ozone depletion in the atmosphere, countries around the world agreed to phase out these chemicals (including CFC’s and HCFC’s) in household and industrial projects. To date, it has been ratified by all countries in the United Nations and the EU; the United States implements the Montreal Protocol through the 1990 amendments to the Clean Air Act.
Despite the effectiveness of this plan, the persistence of these chemicals in the atmosphere means that the hole is still quite large. Best-case scenario predictions are that the hole might be repaired by 2050. That’s more than 50 years after the original treaty entered into force.
It has been said before, but this should serve as a reminder: we are not the result of a single action, but of the small decisions that we make every day. And those impacts may be felt long after we realized they would.