On December 12, 2015, the United States was one of 195 countries to approve the Paris agreement at the Paris summit (or COP21), a global effort to reduce emissions of greenhouse gases and to mitigate the anticipated effects of climate change. The Paris agreement, which becomes effective once adopted by 55 countries that account for at least 55 percent of global greenhouse gas emissions, creates binding procedures and nonbinding emissions targets for each of the participating nations. The COP21 reaffirmed a goal of limiting global temperature increase well below 2 degrees Celsius, and it binds all parties to establish country-specific commitments to reduce emissions and to submit new commitments every five years