An extraordinary meteorological event in 2025 has captured the attention of scientists. The moist winds of the Southwest Monsoon have indicated a rare crossing over the Himalayan mountains into Tibet. This occurrence could be attributed to climate change and global warming, reshaping the weather patterns of South Asia.
Typically, the Himalayas block the monsoon moisture, but satellite images revealed its reach to Tibet. The Southwest Monsoon (SWM) brings rainfall to India from June to September, with moisture drawn from the Arabian Sea and the Bay of Bengal. Usually, these moist winds are halted by the towering peaks of the Himalayas, resulting in rainfall within India.
The Himalayas prevent these winds from reaching Tibet, leaving it arid. Western disturbances bring some snow to Tibet during winter and spring. Yet, in the first week of September 2025, scientists observed through satellite imagery that monsoon moisture reached Tibet via Himachal Pradesh, Uttarakhand, and Ladakh.
Source: aajtak
According to Manish Mehta, a glaciologist at the Wadia Institute of Himalayan Geology, satellite maps clearly show the moisture traveling beyond the Himalayas into Tibet, a truly exceptional meteorological event given that the Himalayas typically act as a barrier.
Why This Change?
Scientists believe climate change and global warming might be linked to this occurrence for several reasons...
The Role of Western Disturbances:
In the 2025 monsoon season, there were 19 western disturbances, above the normal count, with three occurring in the first week of September. Western disturbances usually activate in winter, but their increased occurrence during the monsoon suggests they might have helped transport moisture beyond the Himalayas.
Atmospheric Rivers:
Roxy Mathew Koll from the Indian Institute of Tropical Meteorology (IITM), Pune, noted that western disturbances or atmospheric rivers (part of the subtropical jet stream) could transport monsoon moisture across the Himalayas. More data is needed to assess the rarity of this event.
Source: aajtak
The Impact of Global Warming:
The emission of greenhouse gases is increasing Earth's temperature, altering weather processes. As the snow in the Himalayas and Tibet diminishes due to heat, pathways for moisture to traverse might open. Professor Raghu Murtugudde from the Indian Institute of Technology (IIT), Bombay, observed that strong winds carrying moisture up the slopes can lead to cloudbursts, potentially allowing moisture to reach Tibet.
Himalayan Geographic Structure:
Certain scientists suspect there may be low-elevation passages in the Himalayas through which moisture reached Tibet. Studying local topography is crucial for understanding this occurrence.
Why Is This Event Significant?
The crossing of moisture over the Himalayas to Tibet signifies a significant seasonal shift with numerous causes and effects...
Evidence of Climate Change:
This event highlights how global warming is altering the foundational weather patterns. The Himalayas, which for centuries impeded monsoon passage, now allow moisture to cross, potentially affecting South Asian weather on a large scale.
Natural Disasters in the Himalayas:
The increase in the number of western disturbances during the 2025 monsoon season brought heavy rainfall, floods, and cloudbursts in the Himalayas. Floods claimed four lives and left 100 missing in Dharali and Harsil villages of Uttarkashi district, Uttarakhand.
Source: aajtak
The Environment of Tibet:
Tibet is typically an arid region with scarce rainfall. Regular arrival of monsoon moisture could alter its ecosystem, impacting flora, fauna, and water resources.
Effects on Agriculture and Water:
With monsoon accounting for 80% of India's rainfall essential for farming, a diversion of moisture to Tibet could reduce rainfall in India, affecting agriculture and water availability.
Opinions of Scientists
Scientists regard this event as unusual but emphasize the need for further study to comprehend its long-term implications. Roxy Mathew Koll stated the importance of determining whether this is an isolated incident or a lasting impact of climate change. Raghu Murtugudde suggested analyzing Himalayan topography based on satellite images to understand moisture pathways.
Source: aajtak
Climate Change and Western Disturbances
The 2025 monsoon season accounted for 19 western disturbances, higher than usual. Five disturbances each were recorded in June, July, and August, with three more in early September. Typically responsible for winter precipitation, their presence during monsoon is atypical.
Scientists attribute these shifts to global warming, as warming western Asia and the Mediterranean shift the jet stream northward, potentially carrying monsoon moisture over the Himalayas.
Future Impacts
Floods and Landslides in the Himalayas: With western disturbances and monsoon moisture converging, the Himalayas could face increased rainfall, flooding, and cloudbursts, posing risks to local communities and the environment.
Moisture Effects in Tibet: Regular rainfall in Tibet could alter its dry climate, impacting glacier melt and river flow.
Changes in the Indian Monsoon: Should moisture be diverted to Tibet, rainfall levels in parts of India may decrease, affecting agriculture and water supply.
Need for Climate Models: Scientists must develop new climate models to understand these changes and their future projections.
