The two-week gathering aims to set new targets for conserving life on Earth.
Japan's Environment Minister Ryo Matsumoto said biodiversity loss would become irreversible unless curbed soon.
Much hope is being pinned on economic analyses showing the loss of species and ecosystems is costing the global economy trillions of dollars each year. Read the full report here.
Source: Richard Black, Environment correspondent, BBC News, Nagoya, Japan.