Northeast India Experiences Climate Zone Transformation: Study Reveals

Climate Shift in Northeast India

Guwahati, Oct 9: A recent study has highlighted a significant transformation in the climate zones of India over the last seventy years, particularly affecting the Northeast region, which has transitioned from a tropical savannah to a temperate climate classification.

This research, carried out by experts from the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM) in Pune, indicates a marked change between the historical climate period of 1951–2020 and the current climate epoch.

The findings reveal that the Northeast has shifted from the Tropical Savannah climate category to the Temperate climate category, a change attributed to rising peak air temperatures in the region.

According to the study, the most significant climate zone alteration observed from 1951 to 2020 is the transition to drier conditions, with the temperate regions moving towards Arid Steppe, while the Northwest and Northeast India have shifted from hot Tropical Savannah to Temperate Hot Summer.

Approximately 7% of the land in both Northwest and Northeast regions has transitioned to a drier climate classification, primarily due to increasing temperatures and decreasing rainfall.

This shift is crucial as Tropical Savannah climates typically maintain warm or hot temperatures year-round, with average monthly temperatures exceeding 18 degrees Celsius and minimal freezing occurrences. In contrast, Temperate Hot-Summer climates experience significant seasonal variations, including very hot summers and cold winters with temperatures dropping below freezing.

The study also indicates a general warming trend across India, with maximum summer temperatures and minimum winter night temperatures consistently rising, while rainfall patterns exhibit considerable regional differences.

Notably, the Western Ghats and Northeast India have seen reductions in monsoonal rainfall, whereas certain coastal and northwestern areas have experienced slight increases.

India's meteorological subdivisions are categorized into six main climate classes: Tropical Monsoon, Tropical Savannah, Arid Desert Hot, Arid Steppe Hot, Temperate Dry Winter Hot Summer, and Cold Mountain.

However, these changes are not uniform nationwide. The Central India homogeneous region has recorded a 2% increase in the Tropical Monsoon climate class from the past to the recent epoch.

In Peninsular India, around 15% of the area has shifted from Arid Steppe Hot to Tropical Savannah, a change linked to increased annual rainfall trends.

The researchers emphasize that these findings illustrate how long-term climate variability is reshaping India's climatic landscape. The ongoing contraction and expansion of various climate zones could significantly impact agriculture, water resources, food security, and livelihoods, especially in areas already sensitive to temperature and rainfall fluctuations.

This study highlights the importance of incorporating long-term climate changes into agricultural planning, water resource management, and climate adaptation strategies, particularly in the Northeast, where shifts in temperature and monsoon rainfall could have extensive repercussions.