Researchers reveal how dust regulates carbon cycle, climate change

Researchers have recently uncovered that dust plays a critical role in regulating the global carbon cycle and climate change, advancing understanding of Earth's ecosystem and providing new insights for predicting the carbon cycle's evolution under global warming.

The study was carried out by a joint team from the Institute of Tibetan Plateau Research under the Chinese Academy of Sciences (CAS), with British and Swedish collaborators, and the findings were published online in the journal Nature Reviews Earth & Environment on Tuesday.

They analyzed 22 global dust records in sediment cores, and found that since the Cenozoic era, dust deposition in major ocean basins increased stepwise, with sharp rises aligned with Northern Hemisphere ice sheet expansion and aridification in source regions such as Asia, North America and Africa.

"This global pattern is clearly recorded in key areas like the North Atlantic, North Pacific, Philippine Sea, and Southern Ocean," said Fang Xiaomin, co-corresponding author and an academician of the CAS.

Each year, over 4 billion tonnes of dust are released from global land surfaces. As a bridge between land, air and sea, dust from arid and semi-arid regions carries iron, phosphorus and other key nutrients through atmospheric circulation into the ocean.

Zan Jinbo, a researcher at the institute, explained that this process fertilizes marine phytoplankton, boosting ocean productivity and enhancing the carbon-capturing "biological pump," which transfers large amounts of carbon dioxide from the atmosphere into the deep ocean.

The study also showed varying fertilization effects depending on dust origin. Asian glacial dust, rich in reactive iron and phosphorus, has a stronger effect in the North Pacific than highly weathered North African dust.

Since the Middle Pleistocene, intensified glacial erosion on the Qinghai-Xizang Plateau has significantly increased Asian dust nutrient inputs to the North Pacific, altering phytoplankton communities and productivity.

This study is the first to systematically outline the full path of dust from source to ecological impact. The team urges future research to focus on the nutrient makeup of global dust sources, quantify dust's role in marine carbon uptake, and integrate these insights into Earth system models for better projections of global climate change.