The kyoto protocol was signed in December of 1997 and entered into force as international law in February of 2005. More than 160 countries are parties to the treaty, which is the cornerstone of the global climate change regime. Its main purpose is to impose binding commitments on industrialized nations to reduce their emissions of greenhouse gases, the major cause of global warming, within a specified time frame. The treaty also requires all signatory governments to submit national reports on their efforts to reduce emissions, thereby promoting transparency and compliance.