Oceans across the globe are warming up to four times faster than previously thought, according to the UN.
The North Sea is one of 18 out of 64 ocean areas where rising temperatures could devastate communities and wildlife.
Higher temperatures cause more acidic waters which decimate ocean life, a major source of income and tourism.
Hot pollution being dumped into seas by factories and power plants, plus waters not being protected from the Sun by trees due to deforestation, are mainly to blame.
And the increases could create an ‘accelerated greenhouse effect’ as warmer seas release more carbon dioxide.
Nick Nuttall, spokesman for the UN’s environment programme, which wrote the report, said: ‘A large number of people are dependent on these ecosystems for their livelihood.’
The area of water which has warmed most rapidly is the Baltic Sea, where temperatures have risen 1.35