Natural Dust in Atmosphere Has Doubled Since Start of 20th Century

The increase in dust in the Earth’s atmosphere is influencing climate and ecology around the world.


The amount of dust in the Earth’s atmosphere has doubled since the beginning of the 20th century and the dramatic increase is influencing climate and ecology around the world, according to a new study led by Natalie Mahowald, Cornell associate professor of earth and atmospheric sciences.

It’s the first study to trace the fluctuation of a natural (not human-caused) aerosol around the globe over the course of a century. Mahowald used available data and computer modeling to estimate the amount of desert dust or soil particles in the atmosphere, throughout the 20th century.

Desert dust and climate influence each other directly and indirectly through a host of intertwined systems. Dust limits the solar radiation that reaches the Earth, for example, a factor that could mask the warming effects of increasing atmospheric carbon dioxide. It also can influence clouds and precipitation, leading to droughts – which, in turn, leads to desertification and more dust.

Ocean chemistry is also intricately involved. Dust is a major source of iron, which is vital for plankton and other organisms that draw carbon out of the atmosphere.

To measure fluctuations in desert dust over the century, the researchers gathered existing data from ice cores, lake sediment and coral, each of which contain information about past concentrations of desert dust in the region.

They then linked each sample with its likely source region and calculated the rate of dust deposition over time. Applying components of a computer modeling system known as the Community Climate System Model, the researchers reconstructed the influence of desert dust on temperature, precipitation, ocean iron deposition, and terrestrial carbon uptake over time.

Among their results, the researchers found that regional changes in temperature and precipitation caused a global reduction in terrestrial carbon uptake of six parts per million (ppm) over the 20th century. The model also showed that dust deposited in oceans increased carbon uptake from the atmosphere by 6 percent, or four ppm, over that same time period.

While the majority of research related to aerosol effects on climate focuses on anthropogenic aerosols (those directly emitted by humans through combustion), Mahowald said, the study highlights the important role of natural aerosols as well. “Now we finally have some information on how the desert dust is fluctuating. This has a really big impact for the understanding of climate sensitivity,” she said.


Download Center

  • Waste Management in 2021: Accelerate Your Success with Technology

    Join waste management experts on February 23rd for a live best practice session webinar. You’ll learn how to take your waste program to the next level with visual location, barcoding, and mobility. Register now.

  • Green Quadrant EHS Software 2021

    Reserve your copy of the new report by independent analyst firm, Verdantix, to get a detailed, fact-based comparison of the 22 most prominent EHS software vendors in the industry.

  • Your Guide to Environmental Metrics that Drive Performance

    Translating sustainability into action starts with implementing the right metrics to assess your environmental risk and performance. Learn how to design metrics that improve your decision-making process and drive enterprise performance.

  • 5 Keys to Best-in-Class Chemical Management

    Running a safe chemical program is challenging and complex: from knowing what's on-site to proper handling and disposal - all while navigating regulatory changes. Learn the best ways to mitigate chemical risk, get the most value out of your data, and gain buy-in for a chemical management solution.

  • Unpacking ESG: 6 Questions You Were Too Afraid to Ask

    Environmental and Sustainability experts from Arcadis and Cority answer 6 of the most pressing questions EHS professionals have about getting started with Environmental, Social, and Governance (ESG) reporting.

  • Industry Safe