SAND AND DUST STORM

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Context

• Human activities contribute 25 percent of global dust emissions, with agriculture being the main anthropogenic source, according to the United Nations Convention to Combat Desertification (UNCCD).
• UNCCD, which is one of three Conventions that originated at the 1992 Earth Summit in Rio de Janeiro, released policy recommendations during a five-day meeting from November 13-17 in Uzbekistan.

Details

• Sand and dust storms are a meteorological phenomenon characterized by strong and turbulent winds lifting an ensemble of small particles to great heights.
• They are known to have adverse impacts on human health, the environment, and economies.
• They are typically created by thunderstorms or strong pressure gradients associated with cyclones, both of which boost wind speed across a wide area.
• Wind erosion produces 40% of the aerosols in the troposphere (the lowest layer of the Earth's atmosphere).

Main Sources:

• The dry regions of Northern Africa, the Arabian Peninsula, Central Asia, and China are the primary suppliers of these mineral dusts.
• Australia, America, and South Africa all contribute tiny but significant amounts.
• The main sources of sand and dust storms are the world’s drylands.
• About 75 percent of emissions come from natural sources such as hyper-arid regions, topographic depressions in arid areas, and dry ancient lake beds with little vegetative cover.
• Anthropogenic factors such as land-use change, agriculture, water diversion and deforestation contribute to the remaining 25 percent.
• Abandoned cropland, for instance, are a source of sand and dust storms. Further, water consumption in agriculture shrinks water bodies, creating new sources of sand and dust storms.
• For example, the excessive diversion of water from rivers in Central Asia over several decades towards agriculture has shrunk the Aral Sea, a pre-existing lake between Kazakhstan to its north and Uzbekistan to its south.
• It has now become the Aralkum Desert, a significant new source of sand and dust storms.
• Climate Change: Climate change, too, plays a role. Extreme wind events, aridity and frequent, severe and longer droughts worsen the storms.
• Other factors such as high air temperature, minimal precipitation and strong winds also act as drivers, the FAO stated.

Negative Impact

• Sand and dust storms lower the yields and productivity of crops, trees, pastures, and livestock.
• However, many of these impacts have not yet been well-quantified, according to the FAO report.
• For instance, a sand and dust storm that lasted for two days in mid-March 2021 affected an estimated 8,000 people in 2,000 households across 14 of Mongolia’s 21 provinces.
• Further, 10 people lost their lives and 1.6 million livestock were reported missing.

Impact on Power Plants

• They can interfere with energy infrastructure, adversely affecting electricity transmission lines and causing power outages.
• India, China and Pakistan witnessed 1,584 gigawatt-hours (GWh), 679 GWh and 555 Gwh of energy loss, respectively.
• These losses amounted to over Rs. 782 crores for India per year.

Affect Freshwater Sources

• Extreme dust deposition also occurs in the Himalaya-Hindu Kush Mountain range and the Tibetan Plateau, the so-called 'third pole' that provides fresh water to more than 1.3 billion people in Asia.

Increases Ice Melting

• The deposition of dust on glaciers causes a warming effect, accelerating ice melting, with several direct and indirect consequences for society, including food security, energy production, agriculture, water stress, and flood regimes.

On farming

• Dust deposition has had a significant influence on farming in Turkmenistan, Pakistan, and Uzbekistan.
• Much of this dust has a high salt concentration, making it harmful to plants.
• It decreases yield, posing a severe danger to irrigated cotton and other crop productivity.

On Sustainable Development Goals (SDG)

• They have a direct impact on 11 of the 17 UN-mandated Sustainable Development Goals (SDGs).
• Ending all forms of poverty, hunger, good health and well-being, affordable and clean energy, decent job and economic growth, climate action, and so on.

Positive Impact

• They can boost nutrient content in deposition sites, benefiting vegetation.
• Dust deposited on bodies of water can change their chemical properties, resulting in both beneficial and negative results.
• Iron-carrying dust particles can nourish sections of the water, increasing phytoplankton equilibrium and influencing marine food webs.

Way Forward

• Because their effects are complicated, they represent a key emergent issue for Asia-Pacific policymakers.
• Member States must strategize their joint actions, including gaining a better understanding of the socioeconomic impact of sand and dust storms, establishing a coordinated monitoring and early warning system with an impact-based focus, and coordinating actions to mitigate risks in the most vulnerable and exposed geographical areas.

PRACTICE QUESTION Sand and dust storms have become increasingly prevalent across various regions, posing environmental, health, and socio-economic challenges. Examine the factors contributing to the occurrence of sand and dust storms, and discuss their impacts on ecosystems, agriculture, and human health.