GUWAHATI/NEW DELHI – India latest monsoon season has proven that climate change is transforming the life-giving rains into a destructive force, characterized by longer dry spells and more extreme, intense downpours. Although the total rainfall for the season was only 8% above normal, this modest figure masked a pattern of devastating local events across the country.
The Indian summer monsoon, which provides about 80% of India annual rainfall, arrived a week early this year the fastest onset in 16 years. However this early start quickly transitioned into a pattern of severe erratic weather that caused widespread destruction:
Key Disaster Events Across India
• Himalayan Cloudburst: The Himalayan village of Dharali was nearly washed away after a cloudburst in early August. The resulting flash floods left the local market buried under sediment as high as a four-storey building. Scientists suspect melting glaciers and cloudbursts, both linked to a warmer climate, were the cause.
• Punjab Farmland Floods: Punjab, known as India’s “food bowl,” saw crops drowned across an area roughly the size of Greater Manchester, affecting all 23 districts. The deluge was amplified by an unusual overlap between regular monsoon systems and “western disturbances,” which are storm systems typically active only during winter.
• Kolkata Paralysis: The city of Kolkata was brought to a standstill just before the major Hindu festival of Durga Puja. Some areas received an astonishing 332 mm of rain in just a few hours, more than half of London annual rainfall. The culprit was a low-pressure system that formed over the Bay of Bengal, carrying vast amounts of moisture inland.
The spread of extreme rainfall was also observed in cities like Mumbai and Vijayawada, demonstrating a national trend of intense cloudbursts.
Why the Monsoon is Becoming More Extreme
The underlying cause for the monsoon’s increasing erraticism is a warmer atmosphere that can hold more moisture.
• Scientists explain that for every degree of warming, the air can store about 7% more water vapor. When this massive amount of moisture is eventually released, it falls in heavier downpours over shorter periods.
• This trend is visible in India monsoon data: the number of extreme rainfall days (where daily totals exceed the top 10% of the long-term average) has risen sharply across southern and western India since the 1950s.
• Furthermore, climate change is shifting the monsoon system westward, leading to increased rainfall over typically arid northwestern India and decreased rainfall over the traditionally wetter northeast.
The report concludes that the season that sustains life across India is increasingly threatening it, calling for responsible action to limit greenhouse gas emissions and build resilience to the consequences of a changing climate.