Since the 1970s, the ocean has absorbed over 90% of the world's excess heat and one-third of carbon emissions. But with the intensification of human activities and the increase in greenhouse gas emissions, seawater temperatures have continued to rise in recent decades. In June of this year, UNESCO reported that the rate of ocean warming has doubled in the past 20 years. The website of New Scientist in the UK recently reported that increasing evidence suggests that extreme temperatures are causing serious damage to the ocean and its organisms, pushing the ocean to the brink of disaster. The number of phytoplankton is decreasing. The Antarctic ice sheet is melting. Algae bloom outbreak. Ocean warming leads to coral bleaching. The global sea surface temperature has repeatedly broken records, according to Gregory Johnson, a researcher at the National Oceanic and Atmospheric Administration (NOAA) in the United States. From 1993 to 2022, the global average sea surface temperature has risen by about 0.42 ℃ every decade. But starting from March 2023, the sea surface temperature has risen by about 0.28 ℃ in just five months. In June of this year, data released by multiple international authoritative climate monitoring agencies showed that the global average sea surface temperature continued to set new records for the same period. On June 13th, NOAA reported that sea surface temperatures in most parts of the world were higher than the historical average for the same period in May, with the tropical Atlantic reaching a historic high. Climate change is the main culprit behind the rise in ocean temperatures. In 2023, for the first time in seven years, El Ni ñ o climate conditions will form in the tropical Pacific region, causing an increase in sea surface temperature in the area. The Secretary General of the World Meteorological Organization, Petrie Taras, pointed out that the El Ni ñ o phenomenon greatly increases the possibility of the sea breaking temperature records again, triggering more extreme heat waves in multiple regions around the world. The severe impact on marine ecosystems has led to a significant increase in ocean temperatures. From January 2023 to May 2024, at least 62 countries and regions worldwide experienced large-scale coral bleaching events - a direct result of ocean warming: coral bleaching occurs when ocean temperatures are about 1 ℃ higher than long-term summer temperatures and persist for 4-6 weeks. Other changes are equally worrying. When marine ecologist Dean Grubbs and others at Florida State University investigated the cause of sawfish deaths in the area, they found that a large number of toxic algae were breeding and reproducing on the seabed. They analyzed that the ocean heatwave in Florida in 2023 disrupted the ecosystem, leading to a massive proliferation of toxic algae and neurotoxin poisoning symptoms in over 50 different fish species. The sawfish may be the most severely affected large marine species. The phenomenon of algal blooms is rampant around the world. A study shows that from 2003 to 2020, the coverage of algal blooms increased by 13.2% and the frequency increased by nearly 60%. In June 2023, algal blooms in the North Sea region of the North Atlantic turned seawater into a dirty orange color, visible from space. This region has experienced extreme high temperatures for the past 18 months, and in June of this year, the temperature in the area was 5 ℃ higher than normal. NOAA scientists say the area is experiencing a fever. Angus Atkinson from Plymouth Marine Laboratory in the UK said that seawater is naturally stratified, with warmer, fresher, and oxygen rich water near the surface; The lower layer is cooler, salty, and nutrient rich water. As ocean temperatures rise, the fusion between water layers decreases, making it difficult for nutrients to rise to the surface and oxygen to sink into the deep sea. The nutrients obtained by phytoplankton have greatly decreased, and in April 2023, the productivity of phytoplankton and bacteria worldwide decreased by 22%. The decline in phytoplankton production is particularly evident in the North Atlantic region. Phytoplankton are not only fewer, but also smaller, and crustacean plankton cannot feed on them, leading to a decrease in the production of mackerel, cod, and herring that feed on plankton. The accelerated melting of the ice sheet is causing sea level rise. In July of this year, scientists from the British Antarctic Survey published a study in the journal Nature Geoscience stating that global warming is causing sea temperatures to rise, and the Antarctic ice sheet is melting at an accelerated pace, leading to a rise in global sea levels and putting coastal areas at risk. Before 2015, the extent of Antarctic sea ice was expanding every winter; But in 2016, there was a sudden "collapse like melting" of Antarctic sea ice, and it has since broken historical records for the lowest values three times. The sea ice coverage rate will decrease to 16.96 million square kilometers in 2023, the lowest level in history. The bottom water of Antarctica is also decreasing. Antarctic bottom water is a cold, high-density water mass formed in the Ross Sea and Weddell Sea around Antarctica, carrying oxygen and nutrients to the depths of the Pacific and Atlantic oceans. But an increase in meltwater and a decrease in sea ice mean a decrease in salinity in Antarctic waters, making it more difficult for them to sink. Research shows that over the past 30 years, the amount of water in the Weddell seabed has decreased by more than 20%, and the rate of warming is four times that of other sea areas. The warming of seawater will lead to a rise in sea level. In 2023, the global average sea level reached its highest point since satellite records began in 1993. According to current trends, there may be an increase of another 20 centimeters by 2050, which will increase the frequency and severity of floods in coastal areas. Christopher, a scientist at the National Center for Atmospheric Research in the United States, analyzed that global warming has caused an increase in sea surface temperatures, creating conditions for the formation of stronger storms. In July of this year, Hurricane Belle struck the Caribbean Sea, Gulf of Mexico, and the United States, causing multiple deaths. It was also the strongest hurricane of its kind in recorded history since 1851. (New Society)