sea surface

The oceans are warming faster

May 21, 2025 By EarthWise Leave a Comment

A new study has shown that the rate of ocean warming has more than quadrupled over the past 40 years. The study, by researchers at the University of Reading in the UK, helps to explain why there have been unprecedented ocean temperatures in 2023 and 2024.

Global ocean temperatures hit record highs for 450 days straight in 2023 and early 2024. Some of this unusual warmth came from the El Niño that was taking place at the time, but the rest of the increased temperature came from the sea surface warming up more quickly over the past 10 years than in previous decades. In the late 1980s, ocean temperatures were rising at a rate of 0.06 degrees Celsius per decade. According to the recent research, they are now increasing at 0.27 degrees per decade.

The acceleration of ocean warming is driven by growth in the Earth’s energy imbalance, meaning that more energy from the sun is being absorbed by the Earth than is escaping back into space. This energy imbalance has roughly doubled since 2010 as a result of two factors: increasing greenhouse gas concentrations in the atmosphere and reductions in the Earth’s albedo.

Earth’s albedo, the measure of how much sunlight is reflected back into space, has been declining since the 1970s, primarily due to the decrease in snow and ice cover, especially in the Arctic.

The overall rate of ocean warming observed over recent decade is likely to only increase. This underscores the urgency of reducing fossil fuel burning to avoid even more rapid temperature increases in the future.

**********

Web Links

Ocean-surface warming four times faster now than late-1980s

Photo, posted January 18, 2007, courtesy of Alexey Krasavin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

La Niña has arrived

February 26, 2025 By EarthWise Leave a Comment

After seven months of waiting following the end of the recent El Niño condition, La Niña finally showed up in the eastern Pacific Ocean in early December.

El Niño and La Niña are climate patterns in the Pacific Ocean that can affect weather worldwide. Normally, trade winds in the Pacific blow west along the equator, taking warm water from South America towards Asia. To replace the warm water, cold water rises from the depths. During El Niño, trade winds weaken and warm water is pushed back east, toward the west coast of the Americas. As a result, areas in the northern U.S. and Canada are dryer and warmer than usual.

During La Niña, trade winds are stronger than usual, pushing more warm water toward Asia. This results in more upwelling of cooler water from the depths. This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada. During a La Niña year, winter temperatures are warmer than normal in the South and cooler than normal in the North.

According to the report published in January by NOAA, the La Niña that has arrived is not a particularly strong one. Sea surface temperatures are only about 1.3 degrees Fahrenheit below average in the tropical Pacific. The report also suggests that the La Niña condition may not stick around very long.

The El Niño-Southern Oscillation phenomenon adds a natural source of year-to-year variability in global temperatures. The presence of La Niña for at least part of this year may temporarily keep the lid on rapidly climbing global temperatures.

**********

Web Links

La Niña Is Here

Photo, posted November 23, 2011, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The warmest year on record

February 14, 2025 By EarthWise Leave a Comment

It came as no surprise that 2024 ended up as the warmest year on records. It was the hottest year since record keeping began in 1880. The global average temperature was 1.28 degrees Celsius (or 2.3 degrees Fahrenheit) above the 20th-century baseline period of 1951-1980. It was actually 1.47 degrees above the 1850-1900 average.

The Paris Climate Agreement has a goal to keep the global average temperature increase below 1.5 degrees Celsius over the long term. Long term is specified because for more than half of 2024, average temperatures were more than 1.5 degrees above the baseline.

The temperature of an individual year can be influenced by various natural climate fluctuations, such as the presence of an El Niño or a La Niña condition in the Pacific, or volcanic eruptions. A strong El Niño began in 2023 and continued throughout much of 2024. That El Niño has abated, so it is no longer a factor in the global climate condition.

The global temperature is determined using surface air temperature data collected from thousands of meteorological stations as well as sea surface temperature data collected by ships and buoy-based instruments.

When the climate changes, it is observed first in the global mean temperature. Then there are changes seen on a continental scale and then at the regional scale. Finally, changes are observable at the local level. These changes are becoming more and more common as people’s everyday weather experiences become different from any they had encountered before.

**********

Web Links

2024 Was the Warmest Year on Record

Photo, posted August 26, 2015, courtesy of Saskia Madlener / NASA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Warming estuaries

September 13, 2024 By EarthWise Leave a Comment

Estuaries and their surrounding wetlands are bodies of water where freshwater from rivers and streams mixes with salt water from the ocean to create brackish water. These brackish ecosystems support many unique plant and animal communities around the world.

But ocean water temperature around the world continues to warm. In fact, from 1901 to 2023, the average sea surface temperature has increased by 0.14°F per decade, and 2023 was the warmest year on record.

While sea surface temperatures are on the rise, the problem is more pronounced in South Florida’s estuaries. According to a new study by researchers from the University of South Florida College of Marine Science and the National Park Service, estuaries have experienced rapid warming over the past two decades.

In fact, the research team found that sea surface temperature in four estuaries in South Florida – Florida Bay, Tampa Bay, St. Lucie Estuary and Caloosahatchee River Estuary- has risen around 70% faster than the Gulf of Mexico, and 500% faster than the global oceans.

Their findings, which were recently published in the journals Environmental Research Letters and Estuaries and Coasts, paint a troubling picture for the marine life that calls South Florida’s estuaries home.

The research team has speculated about the possible causes of the rapid rate of warming, including evaporation, water capacity, and residence time, but no single factor has been revealed as dominant.

The researchers hope to partner with colleagues at the Florida Fish and Wildlife Conservation Commission and NOAA to explore the potential impacts of water temperatures on seagrass and coral populations in South Florida.

**********

Web Links

Estuaries in South Florida are warming faster than the Gulf of Mexico and global ocean

What is an estuary?

Photo, posted August 18, 2016, courtesy of City of St. Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio