The oceans are warming at an alarming rate, revealing an unprecedented acceleration in their temperature. A recent study shows that this phenomenon has quadrupled over the past four decades.
Between the late 1980s and today, ocean temperatures have increased from 0.06 to 0.27 degrees Celsius per decade. This rapid rise highlights the growing impact of human activities on the global climate.
Published in
Environmental Research Letters, this research sheds light on the reasons behind the record ocean temperatures observed in 2023 and early 2024. Scientists attribute this acceleration to an increasing energy imbalance of the Earth.
Professor Chris Merchant, lead author of the study, compares this situation to a hot water tap being opened wider, rapidly increasing the water temperature. He emphasizes the importance of reducing carbon emissions to slow this warming.
This energy imbalance, due to increased absorption of solar energy and reduced reflection back into space, has doubled since 2010. Greenhouse gases play a major role in this phenomenon, exacerbated by natural events like El Niño.
Global ocean temperatures have reached record levels for 450 consecutive days. Compared to a similar El Niño event in 2015-16, 44% of this record heat is attributed to the acceleration of ocean warming.
Projections suggest that the warming observed over the past 40 years could be surpassed in the next 20 years. This acceleration underscores the urgency of reducing fossil fuel combustion to stabilize the climate.
The study, published in
Environmental Research Letters, provides further evidence of the impact of human activities on global warming. It calls for immediate action to mitigate future effects.
What is Earth's energy imbalance?
Earth's energy imbalance occurs when the planet absorbs more solar energy than it sends back into space. This phenomenon is mainly due to the increase in greenhouse gas concentrations, which trap heat in the atmosphere.
Since 2010, this imbalance has doubled, contributing to the acceleration of global warming. The oceans, by absorbing a large part of this excess energy, play a crucial role in climate regulation.
The consequences of this imbalance are multiple, including an increase in ocean and atmospheric temperatures, as well as changes in global climate patterns. Understanding this mechanism is essential to predict the future impacts of global warming.
Why are oceans warming faster?
Oceans are warming faster due to their ability to absorb excess heat from the atmosphere. This absorption is accentuated by the increase in greenhouse gases, which retain more heat.
The recent study shows that the rate of ocean warming has quadrupled since the 1980s. This acceleration is partly due to natural factors like El Niño, but also to human activity.
The record ocean temperatures observed in 2023 and early 2024 illustrate this trend. Scientists predict that this acceleration could continue, with major implications for the global climate and marine ecosystems.