Earth Nears Hothouse State as Heat Records Pile Up

Scientists say Earth is getting closer to a point where warming takes over and keeps going on its own. New data shows 2026 has a 99 percent chance of ranking among the seven hottest years ever recorded. This comes as greenhouse gases build up and cleaner air lets in more sun. Experts call for fast changes to avoid locked-in heat that could raise temperatures by 5 degrees Celsius or more over centuries.

Background

Global temperatures have climbed steadily for years. Last year ranked as the third warmest compared to the time before heavy industry, from 1850 to 1900. Average temperatures hit levels not seen in at least 125,000 years. The main cause is gases like carbon dioxide and methane that trap heat from the sun. These gases let sunlight in but block heat from leaving the planet.

Emissions of these gases rose 1.1 percent in 2025 to a record high. Carbon dioxide levels in the air reached 425 to 426 parts per million, the highest ever measured. Even though the rise in emissions has slowed a bit, the total keeps growing.

Another factor is cleaner air. Countries like China have cut pollution from factories and ships. These tiny particles, called aerosols, used to block some sunlight and help form clouds that reflect heat away. Now with less of them, more sun reaches the ground and warms things up faster.

Shipping rules changed in 2020 to limit sulfur in fuel. That cut aerosols from ships by 80 percent. Cloud trails behind ships have faded as a result. All this means the planet heats quicker than models predicted just from gases alone.

Natural patterns like La Nina, which cools things a bit, are fading this year. That leaves warming drivers in full force.

Key Details

A U.S. group that tracks climate, Berkeley Earth, looked at data and forecasts. They say there is a 99 percent chance 2026 will be one of the seven hottest years. It has a 51 percent shot at fourth place and 21 percent at second.

Other signs point to trouble. In 2023, land soaked up less carbon than before. Wildfires spewed extra smoke and gases, starting a loop: more fire from heat, more gases from fire, more heat.

Tipping points loom. Sea ice is shrinking. Forests like the Amazon could die back and release stored carbon. Permafrost in Siberia is thawing, letting out methane. Once these flip, they feed warming on their own.

Speeding Up

Warming is picking up pace. Surface temperatures rise steeper than past trends. Air rules help health by cutting aerosols, but that adds heat. The planet now faces a path to 3.1 degrees Celsius by 2100 without big cuts. That beats Paris goals of 1.5 or 2 degrees.

Even at 2 degrees, risks grow. Studies from years back warned of hothouse Earth at that level. Self-loops could push to 5 degrees, with seas rising 10 to 60 meters over time. The last such warm period was millions of years ago.

"The extremely unusual values we are seeing in recent annual average temperatures cannot be explained by rising carbon dioxide levels alone," said Yeh Sang-wook, a professor of marine convergence engineering at Hanyang University.

In places like Korea, heat waves, droughts, heavy rain, and fires will hit harder. These changes already touch safety and money.

What This Means

A hothouse path means warming sticks even if people cut emissions hard. Feedbacks like melting ice and thawing ground take over. Life shifts: more extreme weather, flooded coasts, dying ecosystems.

Land and oceans that absorb carbon weaken. Extra emissions from fires and thaw speed things up. Without sharp turns, temperatures lock high.

"Global temperature increases have entered a stage where they directly affect Korea’s economy and public safety," said O Jae-ho, emeritus professor at Pukyong National University’s College of Environmental and Marine Science and Technology. "Heat waves, droughts, heavy rainfall and wildfires are likely to become more frequent and more severe."

Groups push for changes beyond UN talks. Courts have ruled governments must act on science. Cuts in gases, plus handling feedbacks, offer a way out. Health, security, and jobs can improve with the right steps. The window stays open, but it narrows fast.