Montreal Protocol Archives - State of the Planet

An iceberg in the Arctic with underside visible

Montreal Protocol Is Delaying First Ice-Free Arctic Summer

New research from Columbia climate scientists shows that the 1987 ozone treaty, designed to protect the ozone layer, has postponed the occurrence of the first ice-free Arctic by as much as 15 years.

by Holly Evarts |May 25, 2023

Without the Montreal Protocol, More Intense Tropical Cyclones

Using one of the most advanced atmospheric computer models available, scientists compared our expected future with a scenario in which ozone-depleting substances had never been regulated.

by |February 1, 2016

Playing for the Planet

Scott Barrett, the Lenfest-Earth Institute Professor of Natural Resource Economics and an expert in complex international negotiations, teaches game theory in his Global Collective Action class. Using a simple card game, Barrett helps his students understand the consequences of decision making in complex negotiations, like those involved in climate treaties, where each country’s actions depend on the actions of others.

by |December 10, 2010

Beyond Carbon: How Fixing the Ozone Layer Contributes to Climate Change

The greenhouse effect is not all about carbon dioxide. Several other substances, such as water vapor and methane, also play a key part in trapping radiation. Recently, a family of relatively obscure chemicals called hydrofluorocarbons, or HFCs, has entered the spotlight due to its role in global warming. HFCs are highly potent greenhouse warmers –… read more

by |August 10, 2010