The intensity of extreme rainfall events is estimated to increase by 15%

The intensity of extreme rainfall events is estimated to increase by 15%

Subject :Geography

Section: Climatology

Context:

• Climate warming is causing a decrease in snowfall and an increase in rainfall at high altitudes in the Northern Hemisphere.
• A study has predicted an increase in the risk of extreme rainfall events.

Extreme rainfall events:

• “Extreme rainfall events” refers to instances during which the amount of rain experienced in a location substantially exceeds what is normal. What constitutes a period of extreme rainfall events varies according to location and season.

Study findings:

• Researchers from Lawrence Berkeley National Laboratory, Berkeley, California analysed the data of rainfall from 1950 to 2019 with future projections up to 2100.
• Their results suggest that warming is causing an increase in rainfall extremes within regions of high elevation in the Northern Hemisphere, particularly in regions usually dominated by snowfall.
• On average, the intensity of extreme rainfall events is estimated to increase by 15% per 1 degree C of warming. These patterns are seen both in historical observations and future projections.
• The intensity and frequency of extreme precipitation events are expected to increase as global warming continues to affect the planet.
• Extreme rainfall events are more damaging than similar snowfall events due to their instantaneous runoff, increasing the risk of floods, which can cause infrastructure damage and landslides.
• The estimated rate of increased rainfall in high altitudes is approximately double that of low altitudes, highlighting the increased vulnerability of mountainous regions to extreme precipitation.
• They utilised both a climate reanalysis dataset and future model projections to show that the amplified increase is due to a warming-induced shift from snow to rain.
• The study findings pinpoint high-altitude regions as ‘hotspots’ that are vulnerable to future risk of extreme-rainfall-related hazards, thereby requiring robust climate adaptation plans to alleviate potential risk.

Importance of the findings:

• 26% of the global population lives in or directly downstream of mountainous regions.
• Study results can help in developing sound climate adaptation plans to protect the natural and built environments.
• The amplification of rainfall extremes is likely to be associated with a decrease in snowfall extremes owing to the transition from snow to rain.