An assessment of the world's coral reef ecosystems has found that almost all face a high risk of collapse in the next 50 years mostly due to warming oceans and heat waves. The International Union for Conservation of Nature's assessment was released Thursday on the sidelines of a U.N. biodiversity conference. The assessment found that 96% of shallow-water reef systems are already critically endangered and could collapse by 2075. The Great Barrier Reef in Australia and most of the world's other famous reef systems are critically endangered. That's the highest level of threat.

Promises by nations to spend hundreds of billions of dollars to finance nature and increase protections for oceans around the globe are falling short ahead of a key U.N. biodiversity conference. The warnings from the head of the conference and environmental groups comes as the countries gather Monday in Yerevan, Armenia for the United Nations Biodiversity Conference, or COP17. The conference running from Oct. 19 to Oct. 30 is a chance for countries to take stock of their progress after agreeing to a historic deal in 2022. Countries agreed to protect 30% of land and water considered important for biodiversity by 2030 and raise at least $200 billion by 2030.