India’s Thar Desert, renowned for its parched expanses, might undergo a remarkable transformation due to the impact of climate change, as suggested by a recent study. While many deserts globally are predicted to expand due to rising temperatures, the Thar Desert seems poised to defy this trend and could potentially become verdant within the next century, claim researchers.
Situated partially in Rajasthan and partially in the Punjab and Sindh provinces of Pakistan, the Thar Desert blankets more than 200,000 square kilometers. As the world’s 20th-largest desert and the 9th-largest hot subtropical desert, its potential transformation carries significance.
THE RAINFALL CHANGE
Amidst predictions of desert growth spurred by global warming, the newly published study in the journal Earth’s Future offers a surprising angle on the Thar Desert’s fate. Combining observations and climate model simulations, the research team discovered that mean rainfall over the semi-arid northwest regions of India and Pakistan experienced a 10–50 percent increase from 1901 to 2015.
Under moderate greenhouse gas scenarios, this precipitation is projected to escalate by 50–200 percent.
Interestingly, the study highlights an eastward shift of the Indian monsoon as a critical factor contributing to arid conditions in India’s west and northwest regions. Historically thriving during the monsoon season and supporting the Indus Valley civilizations, these areas have turned arid over time. The researchers propose that a reversal of this trend, coupled with a westward expansion of the contemporary Indian monsoon, could dramatically alter the climate of the west and northwest Indian regions, ushering in a humid “monsoonal” climate.
This transformation might subsequently bolster food security for the growing population of the nation.
THE MONSOON
According to the study’s lead author, B. N. Goswami, from the Department of Physics at Cotton University in Guwahati, comprehending the dynamics of the Indian summer monsoon is pivotal to understanding how climate change could turn the Thar Desert green. The expansion of the warm water pool in the equatorial Indian Ocean, driven by climate change, has caused a westward shift in the Intertropical Convergence Zone (ITCZ). This shift directs rain farther westward over the land during the summer months.
Goswami underscores the uniqueness of this phenomenon to the Indian monsoon and its significance for potentially greening semi-arid regions in northwest India.
The study underscores that this trend could yield significant agricultural and socio-economic transformations in the area.
Collating weather data from South Asia over the past 50 years, the research team, including P. V. Rajesh from the Indian Institute of Tropical Meteorology in Pune, incorporated changes in monsoon duration and intensity. By inputting historical weather and sea surface temperature data into a climate model, they projected future changes under varying greenhouse gas scenarios.
Their analysis indicates the Indian monsoon is indeed extending westward, resulting in a 10 percent decrease in mean rainfall in the northeast and a 25 percent increase in the west and northwest during the historical period.
While the potential benefits of harnessing this increased rainfall are touted, including improvements in food productivity that could reshape the socio-economic landscape, the researchers acknowledge that this unexpected shift presents both opportunities and concerns. As the Thar Desert potentially transforms into a greener landscape, questions about its delicate ecosystem’s balance and broader implications for the environment and local communities continue to drive ongoing research.
