The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on Climate Change. The major distinction between the Protocol and the Convention is that while the Convention encouraged industrialised countries to stabilize GHG emissions, the Protocol commits them to do so.

The Protocol entered into force on 16 February 2005. Currently, there are 192 Parties (191 States and 1 regional economic integration organization) to the Kyoto Protocol to the UNFCCC. The total percentage of Annex I Parties emissions is 63.7%.

Listed in the Annex A to the Protocol are six greenhouse gases (GHG) that Annex I Parties are required to reduce: Carbon dioxide (C02), Methane (CH4), Nitrous oxide (N20), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulphur hexafluoride (SF6).
Listed in the Annex B of Kyoto Protocol are industrially developed countries with quantified GHG emission reduction targets expressed in percentage with respect to referent 1990. In other words, 38 industrially developed countries and 11 countries with economies in transition in Central and Eastern Europe have quantified emission reduction targets. Protocol also enables the Parties to decide which of the six greenhouse gases will be included in their national strategy to reduce GHG.

It is important to say that industrially developed countries with quantified emission GHG emission reduction targets are listed in Annex B of Kyoto Protocol and Annex I of the Convention. The parties which are not listed in Annex I of the Convention are called non-Annex I Parties to the Convention. These countries do not have quantified emission reduction targets, but they are obligated to fulfill general obligations stipulated in the Convention and Protocol.