2018 was the hottest year measured for Earth’s oceans compared with the 1981-2010 average

+200*

+100

0

-100

-200

1955

1965

1975

1985

1995

2005

2015

+200*

+100

0

-100

-200

1955

1965

1975

1985

1995

2005

2015

Guardian graphic. Source: Advances in Atmospheric Sciences. *Change in ocean heat content in zettajoules (10²¹ joules)