Studies examine effects of climate change on deserts, dust levels around world

New Delhi, April 26

Warming of the Arctic is reducing dust levels around the world by changing the way winds blow over deserts, thereby affecting how the dust is transported, according to a new research.

Researchers explained that driven by human-induced climate change, the Arctic region is warming at a rate faster than the rest of the world — known as Arctic amplification.

This process changes the routes of storms and patterns of winds over major sources of dust in West and South Asia namely the Arabian Peninsula and the Thar Desert between India and Pakistan, they said.

The previous studies have documented reducing dust levels across India, particularly northern India, the Persian Gulf Coast and much of the Middle East.

The latest findings implied that increase in greenhouse gas emissions coming from human activities have reduced dust levels, said the researchers, led by Harvard University.

Ironically, this meant that as humans pursue net-zero emissions, winds could likely return to blowing the same way in these regions as they did pre-warming, they said.

Therefore, alongside of emissions mitigation worldwide, the researchers called for anti-desertification measures by the local governments to keep the dust levels in check.

“At the local level, we need to be thinking about stronger anti-desertification actions such as reforestation and irrigation management and how to better monitor urban-level dust concentrations in concert with broad climate mitigation strategies,” said Michael B McElroy, a professor at Harvard University, US, and lead author of the study published in the journal Proceedings of the National Academy of Sciences.

Another study by the researchers at the Chinese Academy of Sciences charted trends in the expansion and shrinking of oases around the world. The findings are published in the journal Earth’s Future.

They found that globally, oases grew by more than 2.2 lakh square kilometres from 1995 to 2020, driven mostly due to intentional oasis expansion projects in Asia.

The researchers also found, however, that desertification drove the loss of more than 1.34 lakh square kilometres of oasis over the same period, also mostly in Asia, leading to a net growth of 86,500 square kilometres over the study period. They used satellite data to look for green, vegetated areas within dryland areas, indicating an oasis, and analysed changes.

The authors said that most of the growth in oases were from the artificial expansion of oases, which may not be sustainable in the future. They called for improving water resource management, promoting sustainable land use and encouraging water conservation.

A study, also published in the journal Earth’s Future in 2023, predicted the Thar Desert to turn green before the turn of this century.