The global climate system is entering a dangerous phase, with Earth’s energy imbalance reaching its highest level in at least 65 years, according to a new report released by the World Meteorological Organization. The findings highlight a rapid acceleration in global warming, driven by rising greenhouse gas emissions and an increasing buildup of heat within the planet’s system.
The report identifies Earth’s energy imbalance the gap between the energy the planet receives from the Sun and the energy it radiates back into space as a crucial indicator of climate change. Under normal conditions, Earth maintains a near balance between incoming and outgoing energy. However, this balance has now been disrupted due to the growing concentration of greenhouse gases in the atmosphere, which trap heat and prevent it from escaping.
According to the WMO, the rate of heat accumulation has increased sharply between 2001 and 2025. Around 91 per cent of the excess heat is being absorbed by the oceans, while 5 per cent is warming the land, 3 per cent is contributing to the melting of ice, and only 1 per cent is heating the atmosphere. This uneven distribution shows that oceans are bearing the brunt of global warming, acting as a massive heat sink for the planet.
Ocean temperatures have risen continuously over the past nine years, each year setting a new record. Scientists note that the pace of warming between 2005 and 2025 is more than double the rate observed between 1960 and 2005. Even if greenhouse gas emissions are reduced immediately, the oceans are expected to continue warming for decades because of the heat already stored within them.
The warming oceans and melting ice are contributing significantly to rising sea levels. Ice sheets in Antarctica and Greenland are losing mass, while Arctic sea ice has declined to among its lowest levels on record. By the end of 2025, global sea levels had risen by approximately 11 centimetres compared to 1993 levels. The rate of sea-level rise has also accelerated, nearly doubling from about 2.65 millimetres per year between 1993 and 2011 to around 4.75 millimetres per year between 2012 and 2025.
These changes pose serious risks to coastal regions around the world, including flooding, saltwater intrusion into freshwater sources, damage to infrastructure, and the loss of ecosystems. The cascading effects threaten livelihoods, food security, water availability, and public health.
The report also highlights a dramatic increase in greenhouse gas concentrations. In 2024, carbon dioxide levels reached their highest point in at least two million years, with the fastest annual rise recorded since modern measurements began in 1957. Methane and nitrous oxide levels are now at concentrations not seen for at least 800,000 years. These gases are the primary drivers of the growing energy imbalance and the resulting warming.
Oceans are not only absorbing heat but also large amounts of carbon dioxide, leading to increasing acidification. Between 2015 and 2024, oceans absorbed about 29 per cent of human-generated carbon dioxide emissions. This has led to a steady decline in ocean pH levels, making them more acidic. According to scientific assessments, ocean acidity is now at its highest level in at least 26,000 years. This is already affecting marine ecosystems, fisheries, and shellfish production, raising concerns for global food systems.
The broader climate trend is equally alarming. The WMO reports that the period from 2015 to 2025 has been the warmest decade ever recorded. Global temperatures are now approximately 1.43 degrees Celsius above pre-industrial levels, with 2024 recorded as the hottest year so far at around 1.55 degrees Celsius above baseline levels.
Reacting to the findings, António Guterres described the situation as a “climate emergency,” warning that every major climate indicator is “flashing red.” He emphasised that the repeated occurrence of record-breaking temperatures over more than a decade is no longer a coincidence but a clear signal of a planet under stress and a call for urgent global action.
The report also points to growing risks for human health and livelihoods. More than one-third of the global workforce around 1.2 billion people is now exposed to extreme heat conditions each year, particularly those working in agriculture and construction. This not only increases health risks but also reduces productivity and income levels.
Despite these growing threats, preparedness remains uneven. As of 2023, only about half of the world’s countries had developed heat warning systems specifically designed for the health sector, and even fewer had integrated climate data into public health planning.
The WMO has called for urgent action to better connect climate science with health systems, enabling governments to shift from reactive responses to proactive prevention. Strengthening early warning systems, improving climate data integration, and accelerating emission reductions are seen as critical steps to mitigate the worsening crisis.
The findings underline a stark reality: even if emissions are reduced today, the impacts of climate change will continue for decades due to the heat already stored in the Earth’s system. The window for action is narrowing, and the need for immediate, coordinated global efforts has never been more urgent.