India’s climate is turning hotter and drier, with large parts of north India changing from temperate to arid steppe and from hot and tropical Savannah to temperate, hot-summer, between 1961 and 2020, a 70-year analysis of rainfall and temperature changes conducted by researchers at the Indian Meteorological Department (IMD) has found.
Marathwada and west Vidarbha, already ravaged by drought and farmer suicides, have moved into a hotter, drier climate zone.
What the study points out
The study titled: Identifying the climate zone shifts of Indian meteorological subdivisions: insights from historical records, by Ananya Karmakar, Rajib Chattopadhyay, Pulak Guhathakurta, K S Hosalikar and Mrutyunjay Mohapatra of the India Meteorological Department and the Indian Institute of Tropical Meteorology, Pune, is published in MAUSAM, IMD’s peer-reviewed journal, this month. The study had set out to investigate historical records of shifts in climate zone modulation across Indian meteorological subdivisions, aiming to uncover the underlying drivers and patterns that have shaped India’s climate landscape by examining historical data, including meteorological observations, proxy records, and historical accounts. This modulation is mainly associated with the increasing trend in temperature and decreasing trend in rainfall,” the study has noted. “The current shrinking and expected disappearance of the tropical savannah and temperate climate zone will cause numerous problems related to food safety and local population displacement. This is something that must be taken into account in future socioeconomic development plans for the country. Overall, the results suggest that the increasing influence of the negative phase of the Victoria Mode plays a pivotal role in modulating rainfall variability and driving the expansion of drier climate classes over Northern India. The continued contraction of tropical savannah and temperate climate zones poses serious risks to food security, water resources, and regional livelihoods. These findings underscore the importance of incorporating large-scale climate variability into long-term agricultural planning and climate adaptation strategies in India,” Karmakar noted.
“Two significant findings came out of this analysis — over the historical period 1951–2020, the major change in the climate zone is the shift to the drier region, i.e. temperate to arid steppe and hot and tropical Savannah to temperate hot summer for the North West and North East homogeneous regions, respectively. The percentage area transformed to the drier region is nearly 7% in both homogeneous regions. Climate zones are defined by temperature and rainfall, and the researchers redrew India’s climate map for successive 30-year periods (epochs), the standard span over which climate is measured, from 1951–1980 to 1991–2020, using IMD’s own observations.
“For the Peninsular India homogeneous region, the climate zones shift towards the wetter zone, from Arid steppe hot to Tropical savannah by 15% due to a mainly increasing trend of rainfall in recent epochs,” the study also noted.
