For the third year in a row, global ocean temperature was the hottest on record in 2021, according to a study published today in the Journal Advances in Atmospheric Sciences. Furthermore, the past five years have seen the hottest ocean temperature in over 60 years.
The increase in ocean temperature is tracking ever higher temperatures recorded on land and in the atmosphere. Scientists blame humans burning fossil fuels — such as coal, oil and natural gas — for the global warming that started during the Industrial Revolution.
As ocean water heats up, it expands. Experts credit 1/3 of sea level rise to expansion. The rest is due to glacier melt running off into the sea.
In addition to sea level rise flooding, warmer ocean water threatens coastal real estate by increasing glacier melt and by fueling stronger tropical storms and hurricanes and more intense rainfall events. It also threatens to contaminate fresh water supplies through saltwater intrusion.
Kevin Trenberth, a study author and scientist at the National Center for Atmospheric research in Colorado, told CNN: “To stop this (trend), we really need to get to net-zero (emissions), and many countries have plans but not enough actions to support those. In the meantime, we must prepare better and build resilience.”
“Changes to engineering design, building codes, and modifications to coastal development plans are recommended in anticipation of increased sea levels and increases in extreme precipitation events, which are already being observed,” according to the study.