[JURIST] The Kyoto Protocol [official website; BBC News Q&A] takes legal effect Wednesday, 90 days after Russia ratified the treaty [JURIST report], providing the necessary number of ratifications for the treaty to come into force. Before becoming effective, the protocol, which aims to slow global warming by cutting greenhouse gas emissions, required countries representing 55% of global greenhouse gas emissions to ratify the treaty. The US and Australia, citing economic reasons, are not parties to the treaty [JURIST report on US position], and several developing countries, including China and India, also have not ratified the Kyoto Protocol. According to the UN's status of ratification [country list, PDF], 141 countries and regional economic integration organizations have deposited instruments of ratifications or approvals, and the total percentage of emissions by parties to the treaty now stands at 61.6%. BBC News has more.