The planet’s climate system is becoming more unstable, with erratic rainfall, extreme heat and unseasonal weather growing more frequent. The World Meteorological Organization’s State of Global Climate Report 2025 highlights Earth’s energy imbalance as a key driver, finding it reached a record high in 2025 and underscoring accelerating disruption from human-driven greenhouse gas emissions.
Earth’s energy imbalance is the difference between incoming solar radiation and outgoing heat. Under stable conditions the two are roughly equal, but rising concentrations of heat-trapping gases—carbon dioxide, methane and nitrous oxide, now at their highest levels in at least 800,000 years—have shifted that equilibrium. “Scientific advances have improved our understanding of the Earth’s energy imbalance and of the reality facing our planet and our climate right now,” said Celeste Saulo. “Human activities are increasingly disrupting the natural equilibrium and we will live with these consequences for hundreds and thousands of years.”
The imbalance has risen since observations began in 1960, with a sharp acceleration over the past two decades. Most of the excess energy is absorbed by the oceans (more than 91%), about 5% is stored in land, roughly 3% contributes to melting ice, and warming of the atmosphere including near-surface temperatures—the temperatures people experience—accounts for only about 1% of the excess.
WMO links the growing imbalance to record ocean heat content, which hit a new high in 2025 and continues a streak of annual records for the past nine years. The rate of ocean warming between 2005 and 2025 has more than doubled compared with 1960–2005, reinforcing the ocean’s role as a critical but increasingly strained buffer against global warming.
The report confirms 2015–2025 as the warmest 11-year span on record. Depending on datasets, 2025 ranked as the second- or third-warmest year, with global temperatures estimated at about 1.43°C above pre-industrial levels; 2024 remains the hottest year recorded.
Greenhouse gas concentrations continue to climb. In 2024, atmospheric CO2 reached its highest level in the last 2 million years, while methane and nitrous oxide were at their highest in 800,000 years. The CO2 increase in 2024 was the largest since modern measurements began in 1957, and real-time observations indicate all three gases continued rising in 2025. Between 2015 and 2024, roughly half of CO2 emissions remained in the atmosphere, while oceans took up about 29% and land sinks about 21%.
The oceans’ uptake of CO2 has driven steady ocean surface pH decline over the past 41 years, contributing to acidification. The IPCC has very high confidence that current surface pH levels are unprecedented in at least 26,000 years. The largest pH decreases have been observed in the Indian Ocean, Southern Ocean, eastern equatorial Pacific, northern tropical Pacific and parts of the Atlantic. Ocean acidification is already affecting biodiversity, ecosystems and food production from fisheries and shellfish aquaculture.
Excess heat is also driving cryospheric changes: roughly 3% of the additional energy warms and melts ice. Greenland and Antarctic ice sheets continue to lose mass, Arctic sea-ice extent in 2025 was the lowest or second-lowest in the satellite record, and exceptional glacier mass loss was reported in Iceland and along North America’s Pacific coast. These losses contribute to long-term sea-level rise, which has accelerated since satellite records began in 1993.
“On a day-to-day basis, our weather has become more extreme. In 2025, heatwaves, wildfires, drought, tropical cyclones, storms and flooding caused thousands of deaths, impacted millions of people and caused billions in economic losses,” Saulo said.
Although the WMO report is global in scope, its findings carry clear implications for India. Vishwas Chitale, Fellow at the Council on Energy, Environment and Water (CEEW), said the assessment confirms recent years as the warmest on record, with most excess heat now absorbed by oceans, accelerating long-term warming and increasing global humidity. Heat extremes are no longer isolated: daytime highs, warm nights, longer heatwaves and rising humidity are intensifying health risks.
A CEEW study cited by Chitale finds nearly 60% of Indian districts face high to very high risk from extreme heat. As a tropical nation with high population density and a large outdoor workforce, India is already close to physiological heat tolerance limits; rising temperatures and humidity will heighten heat stress, affecting health, labour productivity and local economies.
Chitale emphasized the need for long-term heat resilience: strengthen heat-health early warning systems, implement localized heat action plans, and invest in cooling solutions and public health preparedness to manage growing risks.
