Global Temperatures Near Record Highs in 2025 While Oceans Absorb Record Heat

Global average temperatures in 2025 ranked among the top three warmest on record, despite the cooling influence of a La Niña weather pattern. The period encompassing 2023, 2024, and 2025 collectively represents the three warmest years ever recorded globally.

Earth's oceans absorbed a record amount of heat for the eighth or ninth consecutive year, a significant indicator of ongoing planetary warming primarily attributed to human-caused greenhouse gas emissions.

Global Temperature Overview

While 2024 generally remained the warmest year on record, 2025 was consistently reported by various climate monitoring teams, including the World Meteorological Organization (WMO) and the European Copernicus climate service, as either the second or third hottest year globally. This consistent ranking was indicated by data from eight independent datasets, compiled from billions of weather measurements.

The global average temperature for 2025 was reported between 1.4°C and 1.48°C (equivalent to 2.59°F) above pre-industrial levels from the late 1800s or mid-19th century. The last 11 years, from 2015 to 2025, have been the warmest on record.

Scientists noted an acceleration in the warming trend over the past three years, diverging from the linear trend observed over the preceding 50 years.

Ocean Heat Records and Earth's Energy Imbalance

Earth's oceans absorbed a record amount of heat in 2025, marking the eighth or ninth consecutive year of increased heat absorption. The oceans absorbed an additional 23 zettajoules of heat in 2025, which is the highest annual absorption recorded since modern measurements began in the 1960s. This figure surpassed the 16 additional zettajoules absorbed in 2024.

Over 90% of the excess heat from greenhouse gases is absorbed by the oceans, particularly in the top 2,000 meters.

The oceans are estimated to be at their warmest in at least 1,000 years and heating faster than at any point in the past 2,000 years. The rate of ocean warming has more than doubled in the last two decades compared to the average of the preceding 45 years.

The WMO's "State of the Global Climate 2025" report, for the first time, included a measure of the Earth's Energy Imbalance (EEI), which tracks the accumulation of heat within the Earth system. In 2025, the EEI reached its highest level since observations began in 1960. This imbalance indicates a heat surplus, with an acceleration observed in recent years.

The report detailed that 91% of this excess heat is absorbed by oceans, 5% by land, 1% by the atmosphere, and 3% contributes to melting ice.

The increase in EEI averaged approximately 11 zettajoules per year between 2005 and 2025, with the 2025 increase reported as more than double this average.

Causes and Influencing Factors

Scientists attribute the sustained warming primarily to human-caused greenhouse gas emissions, including carbon dioxide, methane, and nitrous oxide from the burning of fossil fuels (coal, oil, natural gas) and forests. These greenhouse gas concentrations are currently at their highest levels in at least 800,000 years.

Scientists attribute the sustained warming primarily to human-caused greenhouse gas emissions, including carbon dioxide, methane, and nitrous oxide from the burning of fossil fuels (coal, oil, natural gas) and forests.

Natural climate patterns also influence global temperatures. A La Niña event in 2025 exerted a cooling influence on global average surface temperatures, following a strong El Niño in 2024. Despite this cooling effect, temperatures remained significantly high, which scientists noted as a point of concern. Forecasts suggest a potential transition to an El Niño phase by the end of the year, which is expected to increase global temperatures.

Scientists are investigating additional factors that may have contributed to recent rapid warming. Theories include reduced soot pollution from ships, peak solar activity, a potential 2022 underwater volcano eruption, and potential changes in cloud cover and aerosols reflecting less solar energy. Some aspects of recent warming may not be fully understood, and more data is needed to draw firm conclusions about long-term implications.

Impacts and Extreme Weather Events

The sustained warmth is associated with ongoing extreme weather events.

These include intensified heat waves, storms, floods, and fires.

Specific examples cited for 2025 include the Los Angeles fires in January and Hurricane Melissa in October, which caused significant flooding in Haiti and other Caribbean regions. Ocean warming contributes to more intense hurricanes and typhoons, heavier rainfall, increased flooding, and prolonged marine heatwaves that affect marine ecosystems.

Approximately 770 million people globally, including 450 million in China, experienced record annual heat. Other areas with record hot spots included Australia, northern Africa, the Arabian peninsula, and Antarctica, which recorded its hottest year. The Arctic recorded its second-hottest year. Polar sea ice cover reached its lowest level since satellite observations began in the 1970s in February 2025. Half of the planet's land surface experienced more days than average with "strong" heat stress (temperatures above 32°C).

These impacts extend to reduced harvests, increased dengue outbreaks, and rising sea levels due to thermal expansion and melting ice.

International Climate Targets

The world is nearing the 1.5°C international target established in the 2015 Paris Agreement, which aims to prevent more severe climate change impacts. Projections from Copernicus and Berkeley Earth indicate this long-term warming threshold could be surpassed by the end of this decade, around 2029.

Some scientists have stated that exceeding this limit is now considered inevitable.

Scientific Perspectives and Future Outlook

Scientists emphasize that future climate change impacts are not predetermined and can be influenced by human actions, including mitigating climate change through emissions reduction and adapting societies to ongoing changes.

Despite a rise in renewable energy adoption, global emissions have continued to increase. The WMO report highlights that key climate indicators are reaching critical levels, pointing to a need for global attention and action.