They cover both.

The 2025 report also connects physical climate trends with their effects on people. For example, approximately 1.2 billion workers are exposed to heat stress each year, while nearly half of the world’s population faces some degree of dengue risk.

The physical indicators — such as temperature and sea level — represent the underlying climate “signal”. Health, food security, population displacement and economic indicators are treated as downstream consequences and documented alongside them.

WMO’s State of the Global Climate report provides an annual operational snapshot based on real-time monitoring networks, including satellites, ocean buoys and weather stations.

By contrast, the assessment reports of the Intergovernmental Panel on Climate Change (IPCC) are periodic scientific syntheses, generally published every six to seven years. They assess the published scientific literature, including research on the attribution of climate change and projections of future conditions.

WMO indicators provide some of the key observational data used in IPCC assessments, but the two serve different purposes: WMO focuses on ongoing monitoring, while the IPCC provides a comprehensive scientific assessment.

WMO’s State of the Global Climate reports are published annually, generally around World Meteorological Day on 23 March. A shorter update is usually released during the preceding autumn, around the time of the UN Climate Change Conference.

Based on this schedule, the next full report is expected around March 2027 and will cover the 2026 calendar year.

Sources: WMO State of the Global Climate 2025 report and the associated COP30 update. Information current as of July 2026.

Key climate indicators are a set of measurements used by the World Meteorological Organization (WMO) in its annual State of the Global Climate report to track changes in the physical state of the Earth’s climate system over time.

Rather than relying on a single metric, such as surface temperature, WMO combines several measurements to monitor global warming, its causes and its physical consequences for the oceans, ice and sea level.

In the State of the Global Climate 2025 report, these indicators are:

• Atmospheric concentrations of greenhouse gases (CO₂, CH₄ and N₂O)
• Global mean surface temperature
• Ocean heat content
• Ocean acidification
• Global mean sea level
• Glacier mass balance
• Sea-ice extent in the Arctic and Antarctic
• Earth’s energy imbalance — included for the first time in the 2025 report

Temperature: The period from 2015 to 2025 has been confirmed as the 11 warmest years on record. The year 2025 ranked as the second- or third-warmest year, at approximately 1.43°C above the 1850–1900 average.

Greenhouse gases: Atmospheric CO₂ rose from approximately 278 parts per million in 1750 to 423.9 parts per million in 2024 — an increase of 53%. Concentrations of CO₂, CH₄ and N₂O all reached record levels.

Ocean heat: The ocean continues to warm and absorb CO₂. Over the past two decades, it has absorbed an amount of heat each year equivalent to approximately 18 times humanity’s annual energy consumption. More than 90% of the planet’s excess heat is stored in the ocean, where warming has accelerated markedly in recent decades.

Sea level: Global mean sea level is now approximately 11 centimetres higher than it was in 1993, contributing to damage to coastal ecosystems, groundwater salinization and flooding.

Sea ice and glaciers: Arctic sea-ice extent reached a record or near-record low. Antarctic sea-ice extent ranked as the third-lowest on record, while glacier loss continued unabated.

Earth’s energy imbalance: Monitored for the first time as a key climate indicator, it reached a record level in 2025.

WMO publishes the full report, headline data and a dashboard of extreme weather events on its website, wmo.int. The report also includes an annex describing the datasets and methodologies used.

Data for individual indicators — such as CO₂ concentrations and sea level — also come from underlying monitoring networks and institutions, including the US National Oceanic and Atmospheric Administration (NOAA), Copernicus Climate Change Service (C3S) and various research consortia cited in the report’s methodology section.

The data are presented in WMO’s annual State of the Global Climate report, drawing on the datasets and methodologies documented in the report itself.

A shorter update is also published each year around the United Nations Climate Change Conference, or COP, to inform the negotiations. The 2025 update was released during the COP30 Leaders’ Summit in Belém, Brazil, providing a scientific reference for the discussions.

The full report is generally launched around World Meteorological Day on 23 March.

Each indicator captures a different aspect of the same phenomenon:

Greenhouse gases: measure the drivers of climate change.

Surface temperature: measures its most familiar symptom.

Ocean heat, sea level, glaciers and sea ice: show where most of the excess energy is going and how the physical climate system is responding.

Earth’s energy imbalance: measures the net effect — the additional amount of energy absorbed by the planet compared with the amount it releases back into space.

Earth’s energy imbalance provides a way of summarizing all the other indicators in a single figure: the difference between incoming solar energy and outgoing heat.

In a stable climate, these two energy flows are approximately equal. However, rising concentrations of greenhouse gases — including carbon dioxide, methane and nitrous oxide, which are now at their highest levels in at least 800,000 years — have disrupted this balance.

WMO added the indicator to provide a single, physically grounded headline measure alongside global temperature.