As climate change continues to drive desertification, one desert is set to undergo a surprising transformation
Climate change is driving desertification across the hottest and driest regions on Earth. By 2050, scientists predict that the Sahara Desert will have grown by more than 6,000 square kilometres; the UN estimates that creeping deserts could eventually drive 135 million people off their lands. However, there is growing evidence to suggest that one desert could undergo a surprising future transformation: it could become greener.
The Thar Desert, also known as the Great Indian Desert, is a vast arid region spanning more than 200,000 square kilometres of northwestern India and southeastern Pakistan, with some 60 per cent located in India’s largest state, Rajasthan. Characterised by its sparse vegetation, extreme temperatures and limited rainfall, it has long been considered one of the most inhospitable environments on Earth. Nonetheless, it is home to more than 16 million people, making it one of the world’s most densely populated desert regions.
Over on the other side of the country, located at roughly the same latitude, the Indian village of Mawsynram holds the record as the wettest place in the world, with an average annual rainfall of 11,872 millimetres. India’s unique geography – bordered by the Arabian Sea to the west and the Bay of Bengal to the east, and abundant in highlands such as the Himalaya and Western Ghats – is responsible for the South Asian monsoon falling in the east while the west of the country remains dry. But meteorologists at Cotton University, India, believe that could soon change, as climate change drives the monsoon further west.
Analysing weather data collected from the past 50 years, the researchers looked at how rainfall patterns have already changed across South Asia, focusing on the duration and main location of the summer monsoon. They found that precipitation has already increased by as much as 50 per cent in the arid regions of western India and eastern Pakistan, and has decreased by ten per cent in India’s humid east.
According to climatologist Bhupendra Goswami, by the end of the century we can expect to see a 150–200 per cent increase in mean rainfall in northwestern India. The findings are ‘counterintuitive’, he says; normally, there is an expectation that climate change will make wet areas wetter and dry areas drier. However, Goswami and his colleagues found that as rising greenhouse gas emissions continue to heat the planet, the Indian Ocean will warm unevenly, heating up faster in the west. It’s this imbalance, they explain, that is causing the monsoon to shift.
Their research, published in the journal Earth’s Future, isn’t the first to suggest that climate change might be turning the Indian subcontinent’s northwest green. In 2017, scientists at the Center for Global Change Science at the Massachusetts Institute of Technology revealed that, since 2002, there has been a ‘revival’ of the Indian summer monsoon – a reversal of a 50-year dry period that brought relatively little rain to northern and central India. More rain, their study showed, was yet to come.
Historical changes to the climate, and the growing pressures of human activity, have driven desertification in the Thar Desert region for thousands of years. An area once home to the thriving Indus Valley Civilisation has suffered from increasingly erratic rainfall and overgrazing that has degraded the soil, leaving farmers struggling. In 2019, efforts began to restore depleted pastures, and native trees and grasses were planted. Goswami says that if managed properly, the increased rainfall could be a good thing for local communities. ‘Harvesting the increased rainfall has the potential for significant increase in food productivity, bringing in transformative changes in the socio-economic condition of people of the region.’
However, as in any semi-arid climate, Goswami explains, seasonal rainfall comes from a limited number of ‘short and intense rain events that lead to an increased frequency of hydrological disasters.’ In 2022, an unusually intense monsoon season saw three times the annual average rainfall across the country, displacing eight million people and causing more than US$15 billion worth of damage to homes and buildings. In Sindh, one of two provinces that lie within the border of the Thar Desert, more than 70 centimetres of rain fell in just two months.
And while increased rainfall may support the growth of vegetation in some areas, it could also lead to the expansion of invasive species and the degradation of fragile desert ecosystems in others. Despite its harsh and arid conditions, the Thar Desert supports a number of plant and animal species that have adapted to survive, such as the chinkara (or Indian gazelle), the critically endangered great Indian bustard, the Indian desert jird (a rodent with a crucial seed-dispersal role), and the endemic Thar Desert gecko. With no clear commitments to drastically cut global emissions, say researchers, the Thar Desert could one day be gone for good.
