Ocean temperatures are now off the charts and scientists are worried | CNN (2023)

FAQs

Why are scientists worried about the warming of the ocean? ›

Warmer oceans can kill off marine life, lead to more extreme weather and raise sea levels. They are also less efficient at absorbing planet-warming greenhouse gases.

The average global sea surface temperature has increased about 1.5^oF since 1901, an average rate of 0.13^oF per decade. The average global sea surface temperature has been consistently higher during the past three decades than at any other time since reliable records began in 1880.

The oceans of the world are warming up, their average temperatures pushed higher and higher each year by human-caused global warming.

Ninety percent of global warming is occurring in the ocean, causing the water's internal heat to increase since modern recordkeeping began in 1955, as shown in the upper chart. (The shaded blue region indicates the 95% margin of uncertainty.) This chart shows annual estimates for the first 2,000 meters of ocean depth.

Increasing ocean heat content is contributing to sea level rise, ocean heat waves and coral bleaching, and melting of ocean-terminating glaciers and ice sheets around Greenland and Antarctica. Heat already stored in the ocean will eventually be released, committing Earth to additional surface warming in the future.

The ocean absorbs most of the excess heat from greenhouse gas emissions, leading to rising ocean temperatures. Increasing ocean temperatures affect marine species and ecosystems, causing coral bleaching and the loss of breeding grounds for marine fishes and mammals.

2023 is on pace to be the hottest, surpassing last year half a degree celsius, and the average by nearly one degree. Since mid-March, the world's oceans have been hotter than at anytime since at least 1982, raising concerns among some climate experts about accelerated warming.

Temperatures in the oceans decrease with increasing depth. There are no seasonal changes at the greater depths. The temperature range extends from 30 °C (86 °F) at the sea surface to −1 °C (30.2 °F) at the seabed.

As the excessive heat and energy warms the ocean, the change in temperature leads to unparalleled cascading effects, including ice-melting, sea-level rise, marine heatwaves, and ocean acidification.

How can ocean temp affect climate? ›

Ocean currents act as conveyer belts of warm and cold water, sending heat toward the polar regions and helping tropical areas cool off. The world's ocean is crucial to heating the planet. While land areas and the atmosphere absorb some sunlight, the majority of the sun's radiation is absorbed by the ocean.

The cooler air over the ocean will flow to the warmer air off the coast, creating what we call a Sea Breeze, thus making it feel a bit cooler when along a waterfront.

As a result, the top 700 meters (2,300 feet) of the global ocean has warmed about 1.5°F since 1901. And scientists recently found that the rate of warming in the top 6,500 feet of the ocean over the past few decades was about 40 percent higher than previously estimated.

Yes, sea level is rising at an increasing rate. With continued ocean and atmospheric warming, sea levels will likely rise for many centuries at rates higher than that of the current century.

RCP2. 6 assumes high technological development, and a levelling off of greenhouse emissions by 2050, followed by a return to 2020 levels by 2100. This pathway predicts a rise in global sea surface temperature of 0.8°C by 2050, and 1.2°C by 2100, relative to 1870–1899 temperatures.

Air temperatures on Earth have been rising since the Industrial Revolution. While natural variability plays some part, the preponderance of evidence indicates that human activities—particularly emissions of heat-trapping greenhouse gases—are mostly responsible for making our planet warmer.

The global ocean surface temperature reached 21.1°C (69.98°F) in early April, the highest recorded ocean surface temperature since records began.

Over the past 100 years, global temperatures have risen about 1 degree C (1.8 degrees F), with sea level response to that warming totaling about 160 to 210 mm (with about half of that amount occurring since 1993), or about 6 to 8 inches.

Additionally, the team found that ocean waters have been steadily warming since 1958, with each decade warmer than the last. Warming has significantly increased since the 1980s. Over recent decades, portions of the Atlantic Ocean, Pacific Ocean and Indian Ocean have warmed the most.

First, glaciers and ice sheets worldwide are melting and adding water to the ocean. Second, the volume of the ocean is expanding as the water warms. A third, much smaller contributor to sea level rise is a decline in the amount of liquid water on land—aquifers, lakes and reservoirs, rivers, soil moisture.

Is the Pacific Ocean getting warmer? ›

UH: Since at least 1980, the tropical Pacific warming pattern has become more La Niña-like in the observations. This means that SSTs are warming faster in the western tropical Pacific Ocean than the eastern Pacific, and that surface winds are blowing stronger from east-to-west along the equatorial Pacific Ocean (5).

Oceans cover 71 percent of the planet and are home to important species and ecosystems that we rely on for food, livelihoods, climate regulation and more. But the oceans need our help. Saving the oceans can sometimes feel like an overwhelming task, but if we all pitch in, we can make a big difference.

Yes. While we cannot stop global warming overnight, we can slow the rate and limit the amount of global warming by reducing human emissions of heat-trapping gases and soot (“black carbon”).

Forecasters from the World Meteorological Organization are reporting increased chances that the global climate pattern known as El Niño will arrive by the end of summer. With it comes increased chances for hotter-than-normal temperatures in 2024.

Climate scientist James Hansen and his colleagues recently said, “We suggest that 2024 is likely to be off the chart as the warmest year on record.”

There will be more plastic than fish

Rivers of pollution flow into the ocean every day, with little sign of slowing down. Marine animals and birds now regularly eat plastic, and so do humans. It is estimated that by 2050 there could be more plastic in the sea than fish. As the plastic piles up, fish disappear.

Water gets colder with depth because cold, salty ocean water sinks to the bottom of the ocean basins below the less dense warmer water near the surface.

Looking at the entire oceans, however, the Pacific Ocean is by far the warmest overall ocean because it has about four times the intense sun-heated surface area in the tropics compared with the Atlantic Ocean.

It is true that, typically, the water is colder in the winter—usually between 30 and 40 degrees—and warmer in the summer, sometimes reaching the upper 80s. As you'd expect, the sun beating down on the ocean does have a major effect on the water temperature—but wind plays a significant role in the temperature, too.

Are the ice sheets shrinking? ›

Key Takeaway: Antarctica is losing ice mass (melting) at an average rate of about 150 billion tons per year, and Greenland is losing about 270 billion tons per year, adding to sea level rise.

Mid-latitude temperate regions show greater seasonal fluctuations in surface temperature than the poles or the tropics; an 8-15^o C difference from summer to winter in temperate zones, compared to only ~2^o C in polar and tropical areas.

Higher temperatures will warm the sea. This will result in more heat energy, which will increase the potential for tropical cyclones to develop. As warming also leads to more evaporation, heavy rainfalls and snowfalls become more frequent, making floods and cyclones more severe.

Because the ocean covers 71 percent of Earth's surface, scientists record sea surface temperature (SST) to understand how the ocean communicates with Earth's atmosphere. SST provides fundamental information on the global climate system.

Penetrative solar radiation warms the ocean surface causing more carbon dioxide to be released into the atmosphere. Oceanic processes of air-sea gas fluxes effect biological production and consequentially impacting climate.

Thermal expansion happens when water gets warmer, which causes the volume of the water to increase. About half of the measured global sea level rise on Earth is from warming waters and thermal expansion.

At night, while the land cools off quickly, the water at the surface is kept warmer because the water is mixed around with the warmer water underneath. All of this mixing keeps the temperature in the area more constant, not like the land that goes from hot to cold.

A “supercoolometer”, a device that sounds like it should be used to measure hipsters, has found the coldest seawater on Earth, under Antarctic sea ice.

This causes land areas to heat more rapidly and to higher temperatures and also cool more rapidly and to lower temperatures, compared to oceans. The high heat capacity of water also explains why the temperatures of land near a body of water are more moderate.

Because of human-driven increased levels of carbon dioxide in the atmosphere, there is more CO₂ dissolving into the ocean. The ocean's average pH is now around 8.1 , which is basic (or alkaline), but as the ocean continues to absorb more CO₂, the pH decreases and the ocean becomes more acidic.

How does global warming affect the ocean? ›

First, climate change is causing some serious changes in oceans, including temperature increase, sea level rise, and acidification. Oceans are becoming more acidic as they absorb more CO2 from the atmosphere, and concurrently oxygen levels are decreasing.

Ocean Threats

From coral bleaching to sea level rise, entire marine ecosystems are rapidly changing. Global warming is causing alterations in ocean chemistry and many oceanic processes, and it is threatening many species of marine animals that cannot cope with higher temperatures.

First, ocean warming makes earth less habitable for humans as sea level rises and we lose coastal habitats. Second, ocean warming is making fish smaller, making fish stocks smaller, and change where fish are caught; this becomes a food security problem.

Scientists formerly didn't worry about this process because they always assumed that rivers carried enough dissolved chemicals from rocks to the ocean to keep the ocean's pH stable.

Too much carbon dioxide in the air is a problem, as it causes the Earth to trap more heat. The ocean absorbs about one-quarter of the CO₂ that humans create when we burn fossil fuels (oil, coal, and natural gas). Too much carbon dioxide in the ocean causes a problem called ocean acidification.

The massive amount of carbon dioxide being absorbed by the ocean dissolves in seawater as carbonic acid. This process is known as ocean acidification, and it's literally causing a sea change that is threatening the fundamental chemical balance of ocean and coastal waters from pole to pole.

Ocean acidification, paired up with other climate impacts like warming waters, deoxygenation, melting ice, and coastal erosion, pose real threats to the survival of many marine species.

The most common incidents are injuries from stony coral and sea urchins and stings from jellyfish, fire coral, stonefish, and sea anemones. Most dangerous are activities that lead to drowning, envenomation by box jellyfish, and attacks by sharks.

What is one threat to the ocean? ›

Climate change

It's estimated that 75% of the world's reefs are threatened. Ocean acidification, caused by increased carbon dioxide in the atmosphere, is dissolving the shells of animals such as oysters, shrimp, and lobsters and is having other widespread effects on marine life.

Human development and activity leads to pollution (such as point source, non-point source, and noise pollution) and physical modifications (such as changes to beaches, shores and rivers). In addition, humans have removed most of the large vertebrates from the ocean.

Human activities affect marine life and marine habitats through overfishing, habitat loss, the introduction of invasive species, ocean pollution, ocean acidification and ocean warming.

Intensive use of our ocean and runoff from land-based pollution sources are just two of many factors that stress our fragile ecosystems—and increasingly lead to human health concerns. Waterborne infectious diseases, harmful algal bloom toxins, contaminated seafood, and chemical pollutants are other signals.