Ocean Current: Understanding a Balance at the Heart of Global Climate
Ocean currents act like immense ribbons transporting heat and nutrients across the oceans. According to the IPCC report (2024), the temperature of the North Atlantic has increased by 1.2 °C since 1900, exceeding the global average of the oceans ([academic report](https://www.ipcc.ch/report/ar6/wg1/)). Major currents, including the Gulf Stream, play a central role in the climate stability of many regions, influencing European weather and African monsoons. Alarming signals have appeared: slowdown of the Gulf Stream, reversal of certain flows, and accelerated melting of Greenland.
For scientists, the modification of the ocean current is a key indicator of climate change ([expert report](https://www.nature.com/articles/d41586-023-01996-7)). A weakening of the Gulf Stream could cause colder winters in Northern Europe and increased heatwaves on the East Coast of the United States. The slowdown of deep currents reduces the ocean’s ability to absorb CO₂, thus exacerbating global warming. In 2022, NASA observed an unprecedented stagnation of the Atlantic Meridional Overturning Circulation (AMOC), a pillar of the ocean system ([government data](https://www.nasa.gov/feature/goddard/2022/amoc-atlantic-meridional-overturning-circulation/)).
The ocean current depends on the temperature and salinity of the water. However, the melting of ice injects enormous volumes of freshwater into the North Atlantic, altering the density and slowing the circulation. According to scientific projections ([scientific publication](https://www.science.org/doi/10.1126/science.abh3592)), ocean circulation could drop by 30 to 50% by the end of the century, permanently disrupting regional and global climate.
**To learn more, check out this educational video from France TV Éducation:
[How do ocean currents regulate the climate? (France.tv)](https://www.france.tv/france-4/c-junior/2763137-comment-les-courants-marins-regulent-le-climat.html)**
Change in Ocean Current: Impacts on Temperatures and Weather
The change in the ocean current is not limited to a simple increase in sea temperature. In Europe, this could cause more severe cold waves, while North America would experience more summer heatwaves. The European Environment Agency notes a 15% weakening of the Gulf Stream in thirty years, leading to extreme seasonal temperature variations, sometimes up to +4 °C on the American East Coast ([field survey](https://www.eea.europa.eu/en/newsroom/news/sea-surface-temperature-and-currents)).
In Asia, the monsoon is closely dependent on the ocean current. Its weakening would endanger the food security of millions of people. The Southern Ocean, meanwhile, accelerates the melting of Antarctic ice, altering global ocean circulation and amplifying climate disruption.
Ocean Current and Biodiversity: Major Impacts on Marine Life
The transformation of the ocean current disrupts marine biodiversity. Migratory fish, such as tuna and herring, move their breeding areas over long distances. Corals, very sensitive to water temperature and chemistry, are experiencing new stress. As a result, many species are migrating towards the poles, weakening food chains and fishing.
Ocean Current and Solutions: Preserving Climate Stability
In the face of the evolution of the ocean current, research proposes several solutions. Reducing greenhouse gas emissions is fundamental to slowing the melting of ice. Restoring coastal wetlands and strengthening the resilience of marine ecosystems are concrete strategies explored by scientists. Some pilot projects are even studying innovative devices, such as “thermal pumps,” to locally restore the dynamics of the ocean current ([scientific publication](https://www.science.org/doi/10.1126/science.abh3592)).
Adaptation is also necessary: rethinking coastal infrastructures, adjusting agricultural models, and developing international cooperation for the sustainable management of oceans. Protecting the ocean current means ensuring climate stability, biodiversity, and the safety of populations for tomorrow.
Sources
- Rapport académique (IPCC 2024)
- Rapport d’expert (Nature, 2023)
- Données gouvernementales (NASA, 2022)
- Publication scientifique (Science, 2021)
- Enquête de terrain (European Environment Agency, 2023)
- Vidéo éducative (France TV Éducation)
