Sea levels are rising faster than in the last 4,000 years

2025-10-21 16:52:00, Kuriozitete CNA

Melting glaciers and thermal expansion are driving the 'acceleration' of sea level rise to record levels.

Sea levels are rising faster than at any other time in the last 4,000 years, highlighting the urgent need for global and local action.

New research has warned that climate change and human activities are driving increased flooding, posing a serious flood threat to major cities around the world.

The report says that while rising sea levels are a global problem, China faces a double threat, as its largest and most economically important cities are particularly prone to sinking.

How fast are sea levels rising?

Scientists at Rutgers University examined thousands of geological records from various sources, including ancient coral reefs and mangroves, which are often used as a natural archive of past sea levels.

They reconstructed sea level changes dating back almost 12,000 years, to the beginning of the Holocene, the current geological epoch that began about 11,700 years ago, after the last major ice age ended.

Published in the journal Nature, the findings show that since 1900, global sea levels have risen at an average rate of 1.5 millimeters per year.

Why are sea levels rising?

The study describes two "major forces" that are driving the acceleration of sea level rise: thermal expansion and glacial melting.

As climate change raises the planet's temperature, the oceans are absorbing more heat and expanding. At the same time, ice sheets in the polar regions are melting at an unprecedented rate, adding more water to the oceans.

The Greenland ice sheet lost 80 billion tons of ice during the 12 months from September 2023 to August 2024, marking the 28th consecutive year it has lost more ice than it produces.

Currently one of the world's largest sources of freshwater, the Greenland ice sheet contains water that would cause the equivalent of 7.4 meters of global sea level rise.

For every centimeter of sea level rise, about six million people on the planet are exposed to coastal flooding.

Researchers warn that deltas, flat, fertile regions that are close to water, will be hit hardest by rising sea levels.

These areas are often used for agriculture, transportation and urban development, meaning their disappearance could cause weaknesses in the global supply chain./ CNA