By Lara Sujud | Contributing Writer
In 2022, the temperature of the world’s oceans reached a new record high. Climatologists and oceanographers regard this as a key sign of global warming and a contributor to weather extremes. The latest research has focused on oceans’ record-breaking temperatures and their effects on marine ecosystems and human systems.
According to a recent study published in January 2023, world ocean temperatures have reached their highest level in recorded history since record-keeping began in the 1950s, and ocean warming is accelerating. Results from the study show that ocean temperatures increased by roughly 14 Zetta Joules, which is equivalent to the heat produced by seven Hiroshima atomic bombs exploding each second of every day for a year. The study evaluated basin-wide trends and regional hot spots to better understand how rising ocean temperatures are occurring in the world’s oceans. The findings indicate that the Atlantic, Indian, and Northern Pacific oceans are warming the fastest; this trend is anticipated to continue into the future as greenhouse gas emissions rise. The annual intensity, frequency, length, and size of those “warming anomalies” will continue to increase, partly fueled by current El Niño events.
Oceans are the largest solar energy collectors on Earth and absorb over 90% of the heat surplus that has been trapped by greenhouse gas emissions without significantly raising the temperature. They play a crucial role in regulating the Earth’s climate system because of their ability to store and release heat over extended periods of time. When the ocean absorbs more heat than it releases, its temperature rises. Trapped excess heat is eventually released, melting ice shelves and further warming the atmosphere.
The warming of oceans provides a major concern for human societies and marine ecosystems alike. As the water warms, it expands, raising the sea level. Subsequently, there is the risk of flooding; the world’s coastlines are under the threat of being submerged underwater if the trend continues. The marine fauna and flora are also under threat. For instance, warm waters and heat stress contribute to coral bleaching and the loss of algae that grows on corals. This loss of corals’ main food source plays a critical role in destroying coral reefs.
It is crucial to take action to decrease the amount of greenhouse gas emissions and minimize the impact of ocean warming. This can be achieved by cutting back on the use of fossil fuels, practicing energy conservation in our daily lives, advocating for policies that decrease emissions, and safeguarding and restoring marine ecosystems. By acting quickly and decisively, we can slow down the warming of the oceans and reduce its harmful effects.
Figure 1. Seasonal (3-month) heat energy in the top half-mile of the ocean compared to the 1955-2006 average. Heat content in the global ocean has been consistently above-average (red bars) since the mid-1990s. More than 90 percent of the excess heat trapped in the Earth system due to human-caused global warming has been absorbed by the oceans. NOAA Climate.gov graph, based on data (0-700m) from the NCEI Ocean Heat Content product collection.