An international treaty among industrialized countries that committed to reduce its carbon dioxide emissions and presence of greenhouse gases. Countries came up with this agreement on the occasion of the United Nations Conference on Climate Change in Kyoto, Japan in 1997. They are commissioned with a maximum level of carbon emission and may take part in carbon credit trading. Nations who violate the agreement will be subject to a penalty by lowering its emission limit in the following period.

The protocol divides the countries into two groups: Annex I (developed nations) and Non-Annex II (developing countries). The emission limit is only placed to nations under Annex I. But Non-Annex I group members can participate by putting investment in projects that lower emission level in their nations.