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As can be expected from the global warming caused primarily by greenhouse gases, the temperature increase over the globe is broadly distributed, affecting nearly all land and ocean areas. In 2024, 95.2% of the Earth’s surface was significantly warmer than the average temperature during 1951-1980, 4.6% was of a similar temperature, and only 0.2% was significantly colder. We estimate that 24% of the Earth’s surface set a new local record for the warmest annual average. This includes 32% of the land surface and 21% of the ocean’s surface. Particularly extreme conditions were observed over Central and South America, Africa, parts of Asia, Eastern Europe, the Atlantic Ocean, Indian Ocean, and Western Pacific Ocean. As discussed below, these locations with record warm annual averages are home to approximately 3.3 billion people, including particularly large population centers in Asia, Africa, and South America. In 2024, no places on Earth experienced a record or near-record cold annual average.

https://berkeleyearth.org/global-temperature-report-for-2024/

https://berkeleyearth.org/wp-content/uploads/2025/01/2024TemperatureRankMap-1024x601.png

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Land areas generally show about twice as much warming as the ocean. When compared to the 1850-1900 averages, the land average in 2024 has increased 2.28 ± 0.12 °C (4.11 ± 0.22 °F) and the ocean surface temperature, excluding sea ice regions, has increased 1.15 ± 0.07°C (2.07 ± 0.12 °F). Most of this warming has occurred since 1970. Both land and ocean individually set new observational records in 2024. The following figure shows land and ocean temperature changes relative to the average from 1850 to 1900. The tendency for land averages to increase more quickly than ocean averages is clearly visible.

https://berkeleyearth.org/wp-content/uploads/2025/01/Land-and-Ocean-Time-Series-1024x564.png

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End of the Recent El Niño The emergence of the El Niño weather phenomenon in the middle of 2023 had a significant influence on temperatures during both 2023 and 2024, and is likely the largest short-term contributor to the 2023/2024 temperature spike. This El Niño peaked just before the end of 2023 and ended in June 2024. Central Pacific Ocean cooling continued during the rest of 2024. A new La Niña has begun in January 2025 but is expected to be weak. El Niño is characterized by the emergence of a large area of relatively warm water in the eastern equatorial Pacific. In addition to the immediate warming in the Pacific, El Niño can have far-reaching effects on global circulation and weather patterns. This disruption of weather patterns tends to be associated with an extended period of somewhat increased global average temperatures that can last for months beyond the peak of the El Niño in the Pacific. Its counterpart, La Niña, is associated with relative cooling the Pacific and somewhat decreases global average temperatures. Notably, the monthly time series of ocean average temperatures shifted sharply higher in the middle of 2023 — including the largest January to June ocean warming ever observed — due to dissipation of a strong La Niña and its replacement with El Niño. This warmth peaked late in 2023 but persisted well-above the long-term trend until late in 2024. As discussed below, this temperature excursion is not solely due to El Niño in the Pacific, but was also influenced by unusual warming in other ocean basins, especially the North Atlantic.

https://berkeleyearth.org/wp-content/uploads/2025/01/Ocean-Average-Since-1990-1024x564.png

So, just how unusual is the North Atlantic?


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North Atlantic Warmth The Northern Hemisphere portion of the Atlantic Ocean experienced an extreme warming event during the summer and fall of 2023. A large portion of this warmth has persisted into 2024. Based on historical observations, a deviation from the long-term trend of the size observed in 2023 should occur less than once per century, with the last similar event reported during the super El Niño of 1877/1878.

https://berkeleyearth.org/wp-content/uploads/2025/01/NorthAtlantic-1-1024x564.png

So—will we see another such warming event this century?

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While North Atlantic warming can occur with El Niño, the event observed in 2023 appears to have occurred before El Niño was strongly developed, and is likely to be only weakly connected. We believe that variability in the North Atlantic and other regions is largely responsible for the surge in global mean temperatures in the middle of 2023, before the 2023 El Niño event had gathered strength. The surge is mid-2023 in the North Atlantic appears to have been caused, in significant part, by unusually low levels of Saharan dust at that time. However, as discussed below, a reduction in man-made sulfur aerosols is likely also contributing to the persistent warmth in the North Atlantic. The persistence of warming in the North Atlantic, which was not generally anticipated, may have contributed to the persistence of high global average temperatures in 2024 even after the El Niño had ended. Recent changes may indicate that North Atlantic is also cooling a bit, but the basin remains at temperatures that are warmer than ever observed prior to 2023.

Only trouble with the switch to low sulphur fuels warming the Atlantic is that the North Atlantic usually has cloud cover. However, the next decade should let us tease out the effect of the decrease in aerosols from the marine sector.


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. . .a majority of ocean basins set new records in 2024, with the exception of the Arctic Ocean, South Pacific Ocean, and Southern Ocean.