The Montreal Protocol successfully outlawed harmful chemicals that deplete ozone in the atmosphere, but new research shows the ban had an amazing, unforeseen side effect: drastically slashing greenhouse gas emissions in the US.
A new analysis led by the Cooperative Institute for Research in Environmental Sciences (CIRES) is the first study using atmospheric observations to quantify the impact of the Montreal Protocol on US greenhouse gas emissions.
Between 2008 and 2014, the prohibition on these environmentally harmful chemicals actually eliminated the equivalent of 170 million tonnes of carbon dioxide (CO2) emissions each year.
"We were surprised by the size of the decline, especially compared with other greenhouse gases," says lead researcher Lei Hu.
Specifically, by 2025, the team estimates the Montreal Protocol will effectively reduce US greenhouse gas emissions by the equivalent of 500 million tonnes of CO2 annually compared with 2005 levels.
Of course, the Montreal Protocol hasn't just solved everything in relation to the ozone layer.
Another unintended side effect of the treaty – and this time, not a positive one – was the introduction of hydrofluorocarbons (HFCs). »