Deadly Dubai floods made worse by climate change

#### GS Paper 1

Syllabus: Geography

Source: BBC

Context: Recent deadly storms that submerged Dubai and caused fatalities in Oman were likely exacerbated by climate change, with human-induced heat making the record rainfall 10-40% heavier, according to scientists.

• Meanwhile, across the Arabian Sea in Mumbai, a humid heatwave has persisted in recent days, with relative humidity reaching as high as 55%.

Climate of UAE:

The United Arab Emirates (UAE) typically experiences arid conditions, with heavy rainfall events being rare. However, a recent historic event saw Dubai receiving over 142 mm of rainfall within 24 hours, far surpassing its annual average of 94.7 mm.

Possible Reasons for Dubai Floods:

Reasons | Description

1. 1.Anticyclone Interaction | The presence of an anticyclone prevented a weather system, known as a western disturbance, from moving over West Asia. This interaction may have contributed to the storm system that caused the heavy rainfall and lightning in Dubai.
2. 2.Cloud Seeding Operations | Reports indicate that the UAE National Centre of Meteorology’s cloud seeding operations might have intensified the rainfall from the storm system. Cloud seeding involves the introduction of substances into clouds to enhance precipitation, which could have amplified the rainfall in Dubai.
3. 3.Dust as Natural Cloud Seeders | Excessive dust in the region could have acted as natural cloud seeders, contributing to the heavy rainfall.

Dust particles act as condensation nuclei, facilitating cloud formation similar to the process of man-made cloud seeding.

1. 1.Record Heat and Global Warming | Record heat in recent years, coupled with warming trends in West Asia and the Arabian Sea, created unusual heat conditions. The UAE’s climate has warmed by 0.4°C from the long-term average, as noted in the National Centre of Meteorology’s Annual Climate Assessment 2022.

A warmer atmosphere can hold more moisture, leading to heavier rainfall worldwide, including in Dubai.

1. 1.Warm Sea Temperatures and Evaporation | Global warming has resulted in exceptionally warm water in the seas near Dubai, accompanied by warm air above.

This combination enhances evaporation and increases the atmosphere’s capacity to hold moisture. Consequently, larger amounts of rainfall occur, as observed in recent heavy downpours in Dubai.

1. 1.Atmospheric Pressure Dynamics | According to a senior forecaster at the UAE’s National Centre of Meteorology, a low-pressure system in the upper atmosphere, combined with low pressure at the surface, resulted in air compression.

The pressure squeeze was intensified by temperature differences between the ground level and higher altitudes, creating favourable conditions for powerful thunderstorms.

1. 1.Influence of El Niño and La Niña | Other factors, such as the transition from El Niño to La Niña, could have influenced the weather patterns, potentially contributing to the extreme rainfall in Dubai.

El Niño and La Niña events are natural climate phenomena characterized by variations in sea surface temperatures and atmospheric pressure, which can impact global weather patterns.

Reason for possible hot weather in Mumbai:

Mumbai’s hot weather is attributed to a significant Anticyclonic Effect in the region. Anticyclones, characterized by high atmospheric pressure, induce downward-moving winds that compress and heat up, often leading to heat waves. They can also block other weather systems, exacerbating extreme conditions.

In Mumbai, this anticyclone created a “heat dome” effect, further warming the air. Warm air from West Asia and the Arabian Sea was drawn in and heated by sinking motion, increasing humidity, particularly before the monsoon season. Additionally, the anticyclone may have inhibited the cooling effect of sea breezes at night, resulting in higher-than-usual nighttime temperatures.

Other extreme events in India:

In 2023, India experienced a series of unprecedented climatic events, signalling a concerning new normal attributed to climate change. February (last year and this year) saw record-breaking temperatures, shattering a 123-year-old record. Cyclone Biparjoy formed in the Arabian Sea, lasting 13 days, the longest in over four decades. The India Meteorological Department reported extreme weather events on 314 of 365 days in 2022. These events claimed 3,026 lives and damaged about 2 million hectares of crop area.

Monsoon patterns are shifting, with prolonged deficit rainfall followed by intense downpours, a trend strengthening over decades. The interaction between the southwest monsoon and a low-pressure system called the western disturbance is responsible for recent heavy rainfall in northern India.

difference between Cyclone and Anticyclone:

Feature | Cyclones | Anticyclones

Atmospheric Pressure | Low | High

Wind Direction | Inward, counterclockwise rotation (Northern Hemisphere) | Outward, clockwise rotation (Northern Hemisphere)

Weather Conditions | Stormy, with heavy rainfall and strong winds | Clear skies, calm conditions

Wind Speed | High | Moderate

Air Movement | Upward, converging towards the centre | Downward, diverging from the centre

Impact on Weather Patterns | Disruptive, causing heavy rain, flooding, and storm surges | Generally stable, may block weather systems and lead to heatwaves

Formation Factors | Form over warm ocean waters with low-pressure systems | Form over cool ocean waters with high-pressure systems

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What is Cloud Seeding?

Cloud seeding is a weather modification technique aimed at enhancing precipitation in clouds to increase rainfall or snowfall. It involves the introduction of substances, known as cloud seeding agents, into clouds to induce or enhance the formation of ice crystals or raindrops, depending on the type of cloud and desired outcome. Common cloud-seeding agents include silver iodide, potassium iodide, and sodium chloride. These agents serve as nuclei around which water vapour can condense and form ice crystals, which then grow and fall as precipitation. Cloud seeding is often used in regions experiencing water scarcity or drought conditions to augment water resources, but its effectiveness and environmental impact remain subjects of debate and ongoing research.

Insta Links

• El Nino and Monsoon

Mains Link

‘Climate Change’ is a global problem. How will India be affected by climate change? How Himalayan and coastal states of India are affected by climate change? (UPSC 2017)

Prelims Link

La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino? (UPSC 2011)

• La Nina is characterised by an usually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterised by unusually warm ocean temperature in the equatorial Pacific Ocean.

• El Nino has adverse effect on south-west monsoon of India but La Nina has no effect on monsoon climate.

Which of the statements given above is/are correct?

(a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

Ans: D

The scientific view is that the increase in global temperature should not exceed 2°C above pre industrial level. If the global temperature increases beyond 3°C above the pre-industrial level, what can be its possible impact/impacts on the world? (UPSC 2014)

• Terrestrial biosphere tends toward a net carbon source.

• Widespread coral mortality will occur.

• All the global wetlands will permanently disappear.

• Cultivation of cereals will not be possible anywhere in the world.

Select the correct answer using the code given below:

(a) 1 only (b) 1 and 2 only (c) 2, 3 and 4 only (d) 1, 2, 3 and 4

Ans: B