Amidst bleaching and dying coral reefs and rising ocean temperatures, the disruptive changes in ocean currents pose a dangerous new threat to the planet's sustainability
The relentless increase in ocean temperatures has accelerated the bleaching and death of coral reefs, the most vulnerable of all ecosystems. Worse, it is leading to a potentially disastrous shift in the pattern of ocean currents that play a crucial role in moderating global temperatures, making both summers and winters conducive for life.
Ocean currents are continuous, directional movements of seawater within the oceans, driven by a number of factors, including wind, temperature differences, the direction of the planet's rotation, and differences in water density.
Heat is distributed around the globe to a large measure by ocean currents. They ferry heat from the tropical regions to the poles, moderating coastal climates and influencing land weather patterns. On the other hand, cold ocean currents bring cooler water from higher latitudes to the equator, helping to regulate temperature extremes.
The Northern Hemisphere witnessed the worst coral bleaching ever in 2023. The Southern Hemisphere is poised to follow in early 2024.
Coral bleaching was rampant across the Caribbean, the east and west coasts of Mexico and Central America, Kiribati, Fiji, and Eastern New Guinea. According to local observers, coral reefs in these regions suffered near-total bleaching and died.
The temperatures of all major warm currents soared during 2023, suggesting an accelerated transfer of heat from the tropics to the polar regions, says the study. Temperatures were analysed based on infrared emissions from the sea surface.
The tropics remain relatively cool, while the sub-polar oceans experience the greatest heating, leading to accelerated polar ice melting and increased ocean stratification. These changes could impact ocean currents, potentially leading to severe changes in global weather patterns and harm to the ecosystem.