Earth being ‘pushed beyond its limits’ as energy imbalance reaches record high | Oceans

Our planet is grappling with a record energy imbalance, which is warming oceans to unprecedented levels, making weather more extreme and threatening health and food supplies, the World Meteorological Organization has warned.

The UN body confirmed that 2015 to 2025 was the warmest period ever measured, but an even darker message was that the increase in temperature felt by humans on the surface represented only 1% of the heat accumulating more rapidly in the wider Earth system.

More than 90% of this excess is absorbed by the oceans, which last year experienced the highest heat content in history. The rate of ocean warming has more than doubled over the past two decades, compared to the average of the previous 45 years.

The authors of the latest annual report on the state of the global climate say it highlights the growing vulnerability of a planet that is increasingly thrown out of balance due to human activity. Burning oil, gas, coal and forests releases heat-trapping greenhouse gases such as carbon dioxide, methane and nitrous oxide, all of which are at their highest levels in at least 800,000 years.

This disrupts the energy balance of the planet. In a well-functioning system, the amount of radiation entering and leaving the Earth system is approximately similar. But excess heat has been accumulating since at least 1960 and has accelerated significantly in recent years.

This is tracked for the first time in the new report, which shows that Earth’s energy imbalance increased by around 11 zettajoules per year between 2005 and 2025, equivalent to around 18 times total human energy consumption. Last year, it was more than double that average.

Currently, humans and other surface life directly experience only a small fraction of this energy reserve, as 91% is absorbed by the oceans, 5% by the land, 1% warms the atmosphere, and 3% melts ice at the poles and high mountains.

But even with just a tiny fraction of this extra energy, the planet’s surface temperatures – the most commonly used measure of global warming – are reaching alarming levels. Last year was the second or third warmest on record, depending on the dataset. World leaders say it is now inevitable that the planet will fail – at least temporarily – the target of limiting heating to 1.5°C above pre-industrial levels set by the Paris agreement. According to them, the disastrous consequences are already evident: poor harvests, worsening dengue epidemics and increasingly severe heat waves, forest fires and storms.

“The state of the global climate is in a state of emergency. Planet Earth is being pushed beyond its limits. All key climate indicators are flashing red,” said UN Secretary-General António Guterres. “Humanity has just experienced the 11 hottest years on record. When history repeats itself 11 times, it’s no longer a coincidence. It’s a call to action.”

The impact on the oceans is not yet fully understood, but the impacts are expected to be even deeper and more lasting. Sea levels are rising at an accelerating rate and sea ice is at its third lowest level on record.

The paper’s authors argue that more heat is moving to depths, affecting circulation and blocking the consequences for thousands of years.

Closer to the surface, heat waves and acidification are a growing problem for corals and other marine life, while melting ice is raising sea levels and weakening the planet’s ability to reflect solar radiation back into space, worsening the energy imbalance.

There is no respite in sight. The Pacific is nearing the end of a La Niña phase, typically associated with cooler surface temperatures across much of the world. By the end of the year, forecasts suggest that this phenomenon could be replaced by an El Niño phenomenon, which would cause more warming. “If we transition to El Niño, we will see a further increase in global temperature and potentially record levels,” said Dr. John Kennedy, the lead author of the WMO report.