Measure the cost of destructive climate change-related impacts in the trillions of dollars, says a United Nations report published Thursday.

The report, which focuses on the world’s 52 Small Island Developing States (or SIDS) found predominantly in the Caribbean and the South Pacific, highlights how the nations and people least responsible for the climate crisis face the most severe damage. However, the report notes, the costs associated with the destruction of low-lying nations, coral reefs, and vulnerable coasts will be felt globally.

According to the UN’s Environment Program (UNEP), the coral reefs in all SIDS regions are already severely impacted by rising ocean surface temperatures. And the report says that the global net loss of the coral reef cover – around 34 million hectares over the coming two decades – will cost the international economy nearly $12 trillion, with the economies and very existence of those small nations especially impacted.