Oceans Under Siege: Warming Waters Signal Deepening Climate Crisis.

The world’s oceans, which have absorbed the majority of the excess heat generated by human-induced greenhouse gas emissions, are now bearing the brunt of climate change. Acting as a crucial shield for human societies, the oceans have kept global temperatures in check—but not without cost.

Marine ecosystems are increasingly experiencing the toll of this protection. Ocean heatwaves, diminishing marine biodiversity, sea-level rise, oxygen depletion, and acidification caused by excessive carbon dioxide absorption are becoming more severe, raising alarms for both ocean health and planetary stability.

According to Angelique Melet, an oceanographer at the European Mercator Ocean monitor, over 90% of the heat trapped by greenhouse gases has been absorbed by the oceans, which are now warming at an accelerated pace. The Intergovernmental Panel on Climate Change (IPCC) reports that the rate of ocean warming has more than doubled since 1993.

Record-breaking sea surface temperatures were recorded in both 2023 and 2024. Although a slight dip occurred at the beginning of 2025, temperatures remain historically high. The Mediterranean Sea, along with the North Atlantic and Arctic, is among the most affected regions, having set temperature records for three consecutive years, according to Thibault Guinaldo of France’s CEMS research center.

The IPCC notes that marine heatwaves have not only doubled in frequency but also grown more intense, lasting longer and affecting larger areas. These warmer waters fuel more destructive storms and severely impact stationary marine species like corals and seagrass. Projections suggest that between 70% and 90% of coral reefs could disappear this century if global temperatures rise by 1.5°C above pre-industrial levels—a threshold expected to be crossed as early as the 2030s.

In addition to warming, the oceans are rising. As water heats up, it expands, and when combined with the melting of ice sheets and glaciers, sea levels increase. Over the past 30 years, the rate of sea-level rise has doubled and could double again by 2100, reaching approximately one centimeter per year. This trend puts around 230 million people living less than one meter above sea level at significant risk from coastal flooding and storm surges.

Ocean acidification is another pressing issue. Since the 1980s, oceans have absorbed 20–30% of human-generated carbon dioxide, increasing acidity. This harms marine organisms such as shellfish and certain plankton that rely on calcium for their skeletons. Simultaneously, oxygen levels are dropping due to the complex interplay of warming and other environmental factors, further endangering marine life.

Adding to the concern is the dramatic loss of sea ice. Combined coverage of Arctic and Antarctic sea ice fell to an all-time low in mid-February, dropping over a million square miles below the pre-2010 average. This reduction leads to more solar energy being absorbed by the oceans, accelerating ice melt and contributing to the phenomenon known as "polar amplification," where warming is more intense at the poles.

While some of these changes are now unavoidable, experts emphasize that reducing greenhouse gas emissions can slow the pace of damage and provide time for necessary adaptation measures.

Source:https://phys.org/news/2025-06-oceans-human-climate-pollution.html

This is non-financial/medical advice and made using AI so could be wrong.