Climate Change: Earth’s Energy Imbalance and Urgent Warnings
Our planet is grappling with a record-breaking energy imbalance, leading to unprecedented ocean warming, more extreme weather events, and threats to global health and food security, as warned by the World Meteorological Organization (WMO). The latest findings paint a stark picture of a world increasingly out of balance due to human activity.
Record-Breaking Heat and Ocean Warming
The United Nations body confirmed that the years 2015-2025 represent the hottest eleven-year period ever recorded. However, a more concerning revelation is that the temperature rise experienced on land represents only 1% of the rapidly accumulating heat within the entire Earth system. A staggering 90% of this excess heat is absorbed by the oceans, which reached their highest heat content in history last year.
The rate of ocean warming has more than doubled in the past two decades compared to the average over the preceding 45 years. This highlights the growing vulnerability of our planet as it drifts further from equilibrium. You can learn more about ocean heat content at NOAA’s Ocean Heat Content resource.
The Root Cause: Greenhouse Gas Emissions
The burning of fossil fuels – oil, gas, and coal – along with deforestation, releases heat-trapping greenhouse gases like carbon dioxide, methane, and nitrous oxide. These gases are currently at their highest levels in at least 800,000 years, disrupting the planet’s natural energy balance.
In a healthy system, the amount of radiation entering and leaving Earth is roughly equal. However, a heat surplus has been accumulating since at least 1960, accelerating in recent years. The new report reveals that Earth’s energy imbalance increased by approximately 11 zettajoules annually between 2005 and 2025 – equivalent to roughly 18 times global human energy consumption. Last year, this imbalance was more than double the average.
Where is the Heat Going?
Currently, only a small fraction of this excess energy directly impacts surface temperatures. 91% is absorbed by the oceans, 5% by land, 1% warms the atmosphere, and 3% melts ice at the poles and on high mountains. Despite this distribution, even this small share of extra energy is driving surface temperatures to alarming levels. Last year was the second or third hottest on record, depending on the dataset.
Dire Consequences and Urgent Action
World leaders acknowledge that breaching the 1.5°C warming limit set by the Paris Agreement is now inevitable, at least temporarily. The consequences are already visible in failing harvests, worsening dengue outbreaks, and increasingly severe heatwaves, wildfires, and storms.
“The state of the global climate is in a state of emergency. Planet Earth is being pushed beyond its limits. Every key climate indicator is flashing red,” stated UN Secretary-General António Guterres. “Humanity has just endured the 11 hottest years on record. When history repeats itself 11 times, it is no longer a coincidence. It is a call to act.”
Impacts on the Oceans and Future Outlook
The effects on the oceans are not yet fully understood, but are expected to be profound and long-lasting. Sea levels are rising at an accelerating rate, and sea ice is at its third-lowest level ever recorded. More heat is penetrating the ocean depths, affecting circulation patterns and locking in consequences for millennia.
Nearer the surface, ocean heatwaves and acidification pose a growing threat to coral reefs and marine life. Melting ice contributes to rising sea levels and reduces the planet’s ability to reflect solar radiation, further exacerbating the energy imbalance.
The outlook remains bleak. With the Pacific transitioning from a La Niña phase (typically associated with cooler temperatures) to an El Niño phase, global temperatures are expected to rise again, potentially reaching record levels. Dr. John Kennedy, lead author of the WMO report, warns, “If we transition to El Niño we will see an increase in global temperature again and potentially to record levels.”
