As the complex story of climate change unfolds, many of the forecasts are grim, but there are exceptions - the lowest-oxygen environments in the ocean would get now get worse, they may improve if climate change weakens the trade winds. Areas of extreme low-oxygen waters could shrink.
Warmer water contains less gas, so climate change is expected to reduce oxygen levels worldwide. Observations show this is already taking place in many places. Declines during the past 20 years in the tropical low-oxygen zones, the lowest-oxygen waters on the planet, had led to a 2008 study proposing that these zones would also get worse over time.