Global warning: Earth is running out of places to bury CO₂

Earth's ability to safely store CO₂ is much lower than previously thought and could reach its limit as early as 2200, according to a study published in the journal Nature.

Currently, carbon capture and storage technology only removes 49 million tonnes of CO₂ per year - Photo: AFP

To keep the Earth’s temperature from rising more than 1.5-2°C above pre-industrial levels, large amounts of CO₂ need to be removed from the atmosphere. One solution is to capture CO₂ from polluting industries and pump it deep into the rocks.

Research led by the International Institute for Applied Systems Analysis (IIASA, Austria) estimates that the Earth can only safely store about 1,460 gigatons of CO₂, far below the 10,000-40,000 gigatons often cited.

Currently, carbon capture and storage technology removes just 49 million tonnes of CO₂ per year, with an additional 416 million tonnes planned. To meet the Paris Agreement target, the figure needed by mid-century is 8.7 gigatonnes/year – a 175-fold increase from today.

Scientists say the Earth's total physical reserves could be as high as 11,800 gigatonnes of CO₂, but when taking into account the risk of leakage from earthquakes, political and technical constraints, the "safely available" amount drops to just 1,460 gigatonnes.

Even if all this capacity were used to suck CO₂ from the atmosphere, the global cooling would be only around 0.7°C – not enough to bring temperatures back below 2°C, given that the 21st century could see up to 3°C of warming.

In addition to the risk of premature depletion of storage space, the authors also warn of environmental risks if CO₂ leaks out, which could form carbonic acid in groundwater, dissolve minerals containing toxic metals, and harm humans and ecosystems.

Some countries with large and stable storage capacity, such as Indonesia, Brazil or parts of Africa, could become the "center of carbon burden" for rich countries with high emissions. Expert Mathew Gidden (IIASA) commented: "There will be winners and losers, between those who cause climate change and those who actually have to handle that carbon."

Some others argue that the 1,460 gigatonne figure is overly conservative, as with current technology CO₂ injection could still be carried out even in seismically hazardous areas if technical regulations are followed.

However, scientists agree that the Earth's carbon storage capacity is limited and cannot be the only solution to climate change.

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VNA

Source: https://tuoitre.vn/canh-bao-toan-cau-trai-dat-sap-het-cho-chon-co-20250904113457386.htm