It is unacceptable that the Earth’s oceans — vast expanses of water that have long been considered the heartbeat of our planet — are currently undergoing a profound transformation. The current state of the world’s ocean water presents a noteworthy concern, as it is exhibiting temperatures that surpass any previous records. This increasing warmth ought to serve as a stark indicator, sounding a crucial warning to the global community.

In recent years, scientists from around the world have warned of the startling phenomenon that is the record-breaking temperature rise being observed in our oceans.

A recent collaborative analysis conducted by a team of scientists from China, the US, New Zealand and Italy, published this month in the Advances in Atmospheric Science journal, revealed a substantial increase in oceanic heat in 2023. The findings indicated an annual rise of 15 zettajoules, which is about 25 times greater than the total energy produced by all human activities worldwide in 2021.

This unprecedented rise in temperatures has far-reaching implications. Firstly, however, it is important that we delve into the complexities of this issue in order to comprehend why our oceans are experiencing such alarming warmth and to understand the underlying mechanism.

Driven primarily by human activities such as the burning of fossil fuels and deforestation, climate change has unfortunately led to a rise in greenhouse gas concentrations in the atmosphere. These gases, such as carbon dioxide and methane, trap heat and contribute to the warming of the Earth’s surface. A significant portion of this excess heat is then absorbed by the oceans, which are acting as a colossal reservoir that plays a crucial role in regulating the planet’s climate.

The oceans act as a colossal reservoir that plays a crucial role in regulating the planet’s climate

Dr. Majid Rafizadeh

The vastness of the oceans has historically served as a buffer against the impacts of climate change. Oceans absorb and store massive amounts of heat, modulating global temperatures and mitigating the effects of rising greenhouse gas levels. However, this resilience has now become a cause for concern, as the sheer volume of heat absorbed by the oceans is pushing them to unprecedented temperatures, challenging their capacity to act as an effective heat sink.

The problem is that the intensification of human activities, particularly the burning of fossil fuels and deforestation, has significantly contributed to the alteration of the Earth’s climate. The release of greenhouse gases into the atmosphere has enhanced the greenhouse effect, trapping more heat and leading to an overall warming of the planet. This anthropogenic influence has direct repercussions for the oceans, as they absorb the lion’s share of this excess heat.

One of the major threats is that the warming of the oceans has been exacerbating the melting of the polar ice caps and glaciers. As these icy expanses thaw, they contribute to rising sea levels, posing a serious threat to coastal communities and low-lying regions. The global economy, particularly industries tied to coastal regions, faces substantial risks as a result. These include impacts on trade, shipping and the infrastructure connected with coastal zones.

This synergy between oceanic warming and melting ice creates a feedback loop, intensifying the impacts of climate change and further elevating ocean temperatures. This complex interplay between oceanic warming and various feedback loops amplifies the challenges we face.

The warming of the oceans has been exacerbating the melting of the polar ice caps and glaciers

Dr. Majid Rafizadeh

The second threat is that the temperature increase in the oceans can disrupt established currents and patterns of circulation. These currents play a crucial role in distributing heat around the globe, regulating climate systems and supporting marine ecosystems. The alteration of these patterns can lead to unpredictable and potentially detrimental consequences, impacting marine life, weather systems and ocean-dependent economies.

In addition, the rising temperatures in the oceans pose a direct threat to marine ecosystems. Coral reefs, which are known for their vibrant biodiversity, are particularly vulnerable to thermal stress. Elevated temperatures result in coral bleaching, a phenomenon whereby corals expel the symbiotic algae that provide them with nutrients and color. Prolonged bleaching events can lead to the death of coral reefs, disrupting entire ecosystems and jeopardizing the livelihoods of the communities that are dependent on them.

Furthermore, as ocean temperatures continue to rise, marine species are then forced to adapt or migrate to more suitable habitats. This shift in biodiversity and migration patterns can have cascading effects throughout the food chain, impacting fisheries and the communities reliant on them. It also poses a challenge for the conservation of vulnerable species, as they experience increased threats in the face of a changing climate

In a nutshell, the record-breaking heat currently being observed in our oceans is a clear and urgent signal of the profound changes underway in our climate. Unfortunately, human activities have set in motion a chain of events that are reshaping the very foundation of our planet — the oceans.

The fate of our oceans is intricately linked to the fate of humanity.

• Dr. Majid Rafizadeh is a Harvard-educated Iranian-American political scientist. X: @Dr_Rafizadeh