【新华社】粉尘也能“施肥”？科研人员揭秘其对气候影响之谜

Core Insights - Dust is not only a weather phenomenon but also a potential "invisible driver" of global climate change, playing a crucial role in regulating the global carbon cycle and climate change [1][2] - The research indicates that dust carries essential nutrients over long distances to the oceans, impacting global carbon cycling and climate change [1] Group 1: Dust's Role in Climate Change - A recent study reveals that global dust deposition flux has shown a stepwise increase since the Cenozoic era, correlating with the expansion of Northern Hemisphere ice sheets and the aridification processes in regions like Asia, North America, and Africa [1] - The study analyzed dust records from 22 oceanic cores, confirming this global trend in key areas such as the North Atlantic, North Pacific, Philippine Sea, and Southern Ocean [1] Group 2: Nutrient Transport and Marine Productivity - Over 4 billion tons of dust are released from land annually, acting as a critical link between land, atmosphere, and ocean, with dust from arid regions carrying iron and phosphorus, which are limiting nutrients for marine life [1] - This dust fertilization effect significantly enhances marine primary productivity and strengthens the biological pump, transferring large amounts of CO2 from the atmosphere to the deep sea [1] Group 3: Variability in Fertilization Effects - The study found significant differences in the fertilization effects of dust from various sources, with Asian glacial dust being more effective due to its high content of reactive iron and phosphorus compared to highly weathered North African dust [2] - Since the Middle Pleistocene, increased input of Asian dust into the North Pacific has led to notable changes in phytoplankton community structure and productivity [2] Group 4: Future Research Directions - The research highlights the need for future studies to focus on the nutrient composition of major global dust source regions and to establish quantitative links between dust input and oceanic carbon sinks [2] - This understanding is essential for enhancing predictive capabilities regarding global climate change within Earth system models [2]