A recent report from the World Meteorological Organization (WMO), the United Nations’ weather and climate agency, delivers a stark warning: Earth’s climate is now wildly out of balance in ways that have no precedent in recorded history. This alarming conclusion highlights the severity of climate change and the escalating impact of human activity on our planet’s delicate systems. The WMO’s annual climate assessment reveals not only that the past decade has been the hottest on record but also that the fundamental balance of heat entering and leaving our planet’s atmosphere is more disrupted than ever before.
According to the report, the years from 2015 through 2025 mark the 11 hottest years ever documented globally. This prolonged heatwave is not merely a statistical anomaly but a clear signal of the planet being pushed beyond its natural limits. António Guterres, the United Nations Secretary-General, underscored the gravity of the situation in a video message accompanying the report, noting that “every key climate indicator is flashing red.” The imbalance in the Earth’s energy budget—the difference between the heat absorbed from the sun and the heat radiated back into space—is now at its most extreme level since scientists began tracking these measurements. This particular imbalance indicator was introduced in this year’s report for the first time and shows a troubling trend that has worsened steadily since the 1960s, with a dramatic acceleration in the past two decades.
At the heart of this imbalance is the relentless increase in greenhouse gases, especially carbon dioxide and methane, which trap heat in the atmosphere. Human activities, primarily the burning of fossil fuels, contribute to these rising gas concentrations. The report highlights that carbon dioxide levels are now the highest they have been in two million years, while methane concentrations are at their peak in 800,000 years. These gases act like a thermal blanket around the Earth, capturing heat that would otherwise escape into space.
The consequences of this heat trapping are profound. Remarkably, about 91 percent of the excess heat generated by this imbalance is absorbed by the world’s oceans. This has led to record ocean heat levels in 2025, with the rate of heat absorption in the oceans doubling over the past 20 years compared to the previous 40. Oceans act as a massive reservoir for excess heat, but this warming has cascading effects on marine ecosystems, sea level rise, and global weather patterns.
While only about one percent of the excess heat remains in the atmosphere near the Earth’s surface, this is sufficient to drive dangerous and costly weather extremes. The rising temperatures are fueling a surge in climate-related disasters worldwide, including devastating heat waves, floods, and droughts. For example, the western United States is currently experiencing record-smashing heat waves, while Hawaii recently endured severe flooding. Simultaneously, many regions around the world face persistent and severe drought conditions, threatening water supplies, agriculture, and livelihoods.
WMO Secretary-General Celeste Saulo emphasized the long-term nature of these changes, stating, “Human activities are increasingly disrupting the natural equilibrium and we will live with these consequences for hundreds and thousands of years.” This acknowledgment highlights that even if global emissions were drastically reduced overnight, the impacts of the current imbalance and accumulated greenhouse gases would persist for generations to come.
The report also warns that 2026 could see an exacerbation of these extreme conditions due to the potential onset of El Niño, a natural climate phenomenon known for driving global temperature spikes and raising ocean temperatures further. El Niño events historically correlate with record heat years and extreme weather, which could compound the already critical situation outlined in the WMO’s findings.
The human toll of these climate shifts is already evident. António Guterres reminded the global community that these scientific findings are not abstract data points but realities affecting millions of people’s lives daily. Heat waves, floods, and droughts lead to loss of life, displacement, damage to infrastructure, and economic hardship, underscoring the urgent need for climate action.
The WMO report stands as a call to action for governments, businesses, and individuals worldwide. It makes clear that the planet’s climate system is under unprecedented stress and that efforts to mitigate greenhouse gas emissions and adapt to the changing environment must be intensified immediately. The scale and speed of the changes demand coordinated global responses to avoid the most catastrophic outcomes.
Andrea Thompson, the senior editor for life sciences at Scientific American and the author of the report summary, has devoted nearly two decades to covering environmental and earth sciences. Her expertise underscores the importance of communicating these complex issues