International “State of the Climate” Report Confirms Record-high Greenhouse Gases, Global Sea Level, and Ocean Heat in 2025

The 36th annual State of the Climate report, led by scientists at the National Oceanic and Atmospheric Administration was released by the American Meteorological Society on 10 August. The key takeaways: greenhouse gas concentrations, global sea level, and ocean heat content all reached record highs in 2025.

Notable findings:

• Earth’s greenhouse gas concentrations were the highest on record
• Record and near-record temperatures were notable across the globe
• Despite cool ENSO and weak La Niña conditions, sea surface temperatures were at near-record-high levels
• Ocean heat and global sea level were the highest on record
• The Arctic saw near-record warmth
• Antarctica saw record warmth and continued low sea ice; and
• Glaciers around the world continued to melt.

Fuller detail from the press release and executive summaries:

• Earth’s greenhouse gas concentrations were the highest on record. Carbon dioxide (CO2), methane, and nitrous oxide —-Earth’s major atmospheric greenhouse gases-— once again reached record-high concentrations in 2025. The globally averaged CO2 level reached 425.6±0.1 parts per million, a 53% increase from the preindustrial level of ~278 parts per million. Fossil fuel emissions in 2025 were also a record high in 2025, estimated to be 10.3±0.5 petagrams of carbon per year, more than three times the 3.0±0.2 petagrams of carbon per year in the 1960s. (One petagram is equal to more than 2.2 trillion pounds.)
• Record and near-record temperatures were notable across the globe. The 2025 global mean temperature across land and ocean was among the three highest years on record, with records dating back as far as the mid-1800s. Near-neutral and La Niña-like conditions occurred in the eastern Pacific Ocean throughout the year, making 2025 the warmest year on record in which no El Niño conditions were present. Europe reported its warmest year on record, and Russia, China, the Republic of Korea, and Argentina each reported their second warmest. All five major global temperature datasets used for analysis in the report agree that the last 11 years (2015–25) were the 11 warmest on record.
• Despite cool ENSO and weak La Niña conditions, sea surface temperatures were at near-record-high levels. Cool ENSO (El Niño-Southern Oscillation) conditions were sandwiched between weak La Niña conditions during 2025. Despite the cooler conditions in the equatorial Pacific Ocean throughout much of 2025, the mean annual global sea surface temperature was the third highest in the 172-year record, and 0.38°C above the 1991–2020 average. Approximately 87% of the ocean surface experienced at least one marine heat wave in 2025. Only 26% of the ocean surface experienced at least one marine cold spell.
• Ocean heat and global sea level were the highest on record. Over the past half-century, the oceans have stored almost 90% of the excess energy trapped in Earth’s system by greenhouse gases and other factors. The global ocean heat content, measured from the ocean’s surface to a depth of 2000 meters, continued to increase, and reached new record highs in 2025. Global mean sea level was a record high for the 14th consecutive year, reaching about 111.2 millimeters above the average for 1993, when satellite altimetry measurements began. Warming oceans have contributed an average of 1.6±0.3 millimeters per year to rising sea levels since 2005, while melt from ice sheets and glaciers has contributed an average of 2.0±0.4 millimeters during that same period.
• The Arctic saw near-record warmth. The Arctic had its second-warmest year in the 126-year record. Surface air temperatures in the Arctic are increasing at roughly three times the global average rate. Precipitation is also increasing across the region. In response to the precipitation and temperature increases, tundra plants have been increasing; 2025 marked the third-highest value in the record with respect to greenness, a measure of the increase in plants and productivity. In Arctic waters, maximum sea ice extent in 2025 was the lowest in the 47-year record, while minimum extent was the 11th lowest. The thickness of the sea ice, which is related to its age, has also been decreasing over time. Ice older than four years old is nearly absent, with only 95,000 square kilometers of older ice in September 2025 as compared to 1.5 million square kilometers in the 1980s.
• Antarctica saw record warmth and continued low sea ice. Antarctica observed its warmest year since the start of the record in 1979. Surface melt on the continent was above average on most ice shelves, and melt on the Antarctic Peninsula approached record levels in early January. Surrounding the continent, sea ice remained below average in 2025, following a nearly decade-long trend. Annual daily maxima and minima of sea ice extent were the third and fourth lowest on record, respectively.
• Glaciers around the world continued to melt. Land-based glaciers continued to lose ice for the 38th consecutive year, losing the equivalent of more than 1 meter of water on average for the fourth straight year. About 41% of the loss experienced by glaciers since 1976 has occurred in the last decade.
• Tropical cyclone activity was above average. A total of 97 named tropical cyclones were observed during the Northern and Southern Hemispheres’ storm seasons, above the 1991–2020 average of 87. Five storms reached Category 5 intensity. Three of these storms occurred in the North Atlantic, tying for the second most on record for that basin. Hurricane Melissa became one of the strongest Atlantic hurricanes on record, with a maximum intensity of 190 miles per hour and a minimum central pressure of 892 hPa on October 28. Melissa made landfall in Jamaica as a Category 5 storm, causing devastation on the western part of the island. The storm caused 95 fatalities and resulted in at least $12.2 billion (U.S. dollars) in damage. There were 12 named storms in the Australian basin during the 2024/25 season, which was the most in a season since 2005/06. In February, Tropical Cyclone Zelia reached Category 5 intensity at sea and made landfall as a Category 4 storm in Western Australia. Flood heights at the town of Marble Bar due to heavy rainbands were nearly 2 meters above previous records.

And closer to home, the report on Europe from the Executive Summary, copied here in full:

Europe observed its warmest year on record, with the United Kingdom, Iceland, Norway, and West Kazakhstan each individually reporting record annual warmth. For nearly all other countries across the continent, 2025 temperatures were among their 10 highest on record. There were no areas with below-normal annual temperatures.

It was the warmest summer on record for both Spain and Portugal. A new all-time national daily maximum temperature record of 46.6°C was set on June 29 in Mora, Portugal. A new all-time national daily maximum temperature record of 50.5°C was also set on July 25 in Silopi, Cizre, during a late-July heatwave in Türkiye. That same day, 66 stations broke their own temperature records across the country. In Northern Europe, 28 stations in Norway recorded temperatures of 30°C or higher for at least five consecutive days in July. Two of those stations recorded 13 consecutive days reaching at least 30°C, a new national record in duration. In Sweden, Kvikkjokk-Årrenjarka, which is located just north of the polar circle, recorded 10 days with temperatures above 30°C, breaking the previous record of 4 days, based on measurements extending back for more than 100 years.

Central Europe experienced a prolonged dry spell from early February to late May. Summerwas dry overall for the Iberian Peninsula; it was the driest summer on record for Portugal, with only 24% of its normal total. In Spain, almost 4000 square kilometers was burned in 2025, the most since the start of the record in 2006. Almost 380 square kilometers burned was due to just one fire, which occurred in the Zamora Province in northwestern Spain in August and was the largest single fire on record for the country. At least 12,000 people had to evacuate their homes. During July and August, central Montenegro faced one of its most severe wildfire seasons in the past two decades, with more than 100 square kilometers of forest and agricultural land burnt.

Conversely, the eastern Aosta Valley in northwestern Italy recorded 300 mm in 48 hours during April 15–17 with local maximum values up to 600 mm, triggering river flooding and landslides. In the hardest hit areas, this was considered a 1-in-1000-year event. A severe cloudburst impacted Moscow on July 15, with 75 to 85 millimeters of rain falling in less than two hours—an amount that equaled or even exceeded the city’s typical monthly average for July. In September, Luxembourg received 400% of its normal precipitation, making this the wettest month on record since observations began in 1947. On September 25, more than 130 millimeters of rain fell in the Nahariya area of northern Israel, far exceeding the previous national record for September of 96 millimeters set in 1932. The monthly average is 3 to 4 millimeters. The entire rainfall event occurred in less than four hours, with more than 100 millimeters falling within just two hours.

The most significant storm of 2025 in Western Europe impacted Ireland, the United Kingdom, and northwestern France on January 24. Ireland recorded a 184 kilometer-perhour wind gust at Mace Head—a lowland coastal station—provisionally the strongest gust on record in Ireland. Another storm on December 27 brought exceptionally high winds to eastern central Sweden, with some stations recording gusts up to 170 kilometers per hour, estimated to be a 1-in-100-year event. At least four people died, and Sweden saw its most severe forest damage from a single event since 2007.

[Regional Climates is one chapter from the State of the Climate in 2025 annual report and is available from https://doi.org/10.1175/2026BAMSStateoftheClimate_Chapter7.1. Compiled by NOAA’s National Centers for Environmental Information, State of the Climate in 2025 is based on contributions from scientists from around the world. It provides a detailed update on global climate indicators, notable weather events, and other data collected by environmental monitoring stations and instruments located on land, water, ice, and in space. The full report is available from https://doi.org/10.1175/2026BAMSStateoftheClimate.1.]

And more from the press release:

The international annual review of the world’s climate, published by the American Meteorological Society (AMS), is based on contributions from 625 scientists in 60 countries. It provides the most comprehensive update on Earth’s climate indicators, notable weather events, and other data collected by environmental monitoring stations and instruments located on land, water, and ice, as well as in space. The report is published as a supplement to the Bulletin of the American Meteorological Society (BAMS).

“The State of the Climate is a comprehensive, collaborative international effort to assess annual metrics for the atmosphere, oceans, and cryosphere,” says AMS President Alan Sealls. “It’s peer-reviewed data that paints a global picture of where we are, compared to benchmarks, and how fast things are changing. Consider it analogous to your annual health assessment from your physician. The State of the Climate connects to the health of all ecosystems. It presents critical measurements and trends which inform agencies, communities, businesses, and individuals for long-term planning.”

Links:

• Full report
• Inside Climate News report

And from Bill McKibben:

3.6 degrees Fahrenheit.

That’s how much temperatures have risen on average in Europe since the 1960s, according to the new State of the Climate 2025 report, which veteran analyst Bob Berwyn broke down this week. Just think about that for a moment, because it helps you to understand the scale of what we’ve done. When you walk outside your home, in Europe or America, it’s three degrees hotter than it would have been a just few decades ago. Think of that amount of extra heat (and remember that ninety percent more is stored away in the oceans, waiting to be released).