in our lifetimes and look set to continue for generations to come. the ipcc�*s recent report warns a global ocean rise approaching two metres by the end of the century can't be ruled out. as many as 200 million people could live below sea level by 2100. with 160 million more affected by higher annual flooding. 0cean temperatures are rising too. more than 90% of the excess heat trapped by greenhouse gases is absorbed by the world's oceans, threatening fragile marine ecosystems — from coral and plankton to fish and whales. and c02 from burning fossil fuels dissolves in the oceans, making them more acidic, and posing further threats to marine life. 0ceans absorb nearly 30% of excess carbon dioxide and when absorbed by sea water, the co2 forms carbonic acid it points to huge challenges — and great uncertainty — for many of the ocean's ecosystems.