Warming Arctic reduces dust levels in parts of the planet

 Dust can have a huge impact on local air quality, food security, energy supply and public health. Previous studies have found that dust levels are decreasing across India, particularly northern India, the Persian Gulf Coast and much of the Middle East, but the reason has remained unclear. SEAS researchers found that the decrease in dust can be attributed to the Arctic warming much faster than the rest of the planet, a phenomenon known as Arctic amplification. This process destabilizes the jet stream and changes storm tracks and wind patterns over the major sources of dust in West and South Asia.

Ironically, the best-case scenario for emissions -- carbon neutrality -- could have the worst impact for dust because if humans reduce emissions enough to slow or stop Arctic amplification, then the jet stream and wind patterns would likely return to pre-warming states, which would lead to an increase in dust. The researchers find that as the global community works to reduce greenhouse emissions, local governments should simultaneously be working to address dust reduction.Climate change is a global phenomenon, but its impacts are felt at a very local level.

Take, for example, dust. Dust can have a huge impact on local air quality, food security, energy supply and public health. Yet, little is known about how global climate change is impacting dust levels.

Previous studies have found that dust levels are actually decreasing across India, particularly northern India, the Persian Gulf Coast and much of the Middle East, but the reason has remained unclear. Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are working to understand how global climate change is impacting dust levels in the region.

In a paper published in the Proceedings of the National Academy of Sciences, a team of researchers led by Michael B. McElroy, the Gilbert Butler Professor of Environmental Studies at SEAS, found that the decrease in dust can be attributed to the Arctic warming much faster than the rest of the planet, a phenomenon known as Arctic amplification. This process destabilizes the jet stream and changes storm tracks and wind patterns over the major sources of dust in West and South Asia -- namely the Arabian Peninsula and the Thar Desert between India and Pakistan.

"Local land management, rapid urbanization and industrialization certainly contribute to dust levels West and South Asia but the novel insight from our study is the increasingly dominant influence of circulation change on the broader global climate context," said McElroy. "Changes in atmospheric circulation patterns, driven by global climate dynamics shifts, have emerged as the principal driver behind the observed recent dust reductions in West and South Asia."

Source: ScienceDaily