• The most successful environmental treaty in history is the Montreal Protocol on Substances That Deplete the Ozone Layer (1987). The treaty has since undergone five important revisions and is still going strong.
• In 1992 at the Rio Earth Summit, the UN Framework Convention on Climate Change (UNFCCC) came into being. It was here that world governments agreed to stabilize greenhouse gas emissions.
• In 1997 at the Kyoto Protocol, all Parties came together to legally agree binding greenhouse gas emission obligations. The greenhouse gases named were: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons and Sulphur hexafluoride.
• In 2010, in Cancun, the Parties agreed to limit global warming to a maximum of 2°C compared to pre-industrial levels. Today, global warming is already more than 1°C.
• In 2015, the Paris Climate Agreement Parties agree to limit warming to "well below 2°C" above pre-industrial levels, and to pursue efforts to limit it even further to 1.5°C.
• The planet is currently on course to exceed 3°C.
• UN climate conferences (known as COP - 'conference of the parties') take place every year. In December 2019, COP25 was originally to take place in Santiago, Chile. Up to 25,000 delegates were scheduled to attend. In the end it was switched to Madrid where 26,706 participants attended. Transporting this number of delegates by plane, train or car, emits a significant amount of greenhouse gas emissions.