Sand and dust storms pose global threat

The United Nations plans to tame lethal sand and dust storms with a mixture of modern technology and traditional knowledge.

The standard bearer of the United Nations’ effort to combat desert spread and the threat from sand and dust storms, meeting here, is determined to be remembered as not just a global talking shop, but a launchpad for action.

The UN Convention to Combat Desertification (UNCCD) has launched a coalition to energise the UN’s response to the problem.  One focus for the new body will be to develop the sand and dust storms (SDS) source base map to improve the monitoring of the storms.

Iran told the meeting that both traditional and modern knowledge on SDS hot spots could help to create a stronger knowledge base for regional initiatives. The coalition’s members include  the International Civil Aviation Organization and the World Meteorological Organization (WMO).

The WMO already has an established SDS warning advisory system (SDS-WAS) to research the problem and try to provide forecasts of dangerous storms. Countries are now being asked to explore ways of reducing man-made contributions to dust storms, for example by not denuding land of vegetation.

Climate change and extreme weather have made SDS a threat to more than 150 countries, causing economic damage and threatening health. The storms, once thought of as a local problem in desert or arid regions, are now recognised as a global hazard.

“There is a need for more accurate real-time observations of dust properties and for understanding dust triggering mechanisms, seasonal variabilities, and transport dynamics”

Huge quantities of sand and dust can be lifted into the air by high winds and distributed over hundreds of miles. The problem is worsening as droughts increase and land is degraded by deforestation and poor agricultural practices.

Dust is also intensifying climate change, for example by discolouring ice so that it melts faster, and human health is affected by increased asthma and the spread of diseases such as valley fever and meningitis.

Aviation suffers when storms close airports or cause damage when dust is sucked into engines. Roads are lost under sand and electricity supplies disrupted. Even fisheries are damaged by sand settling in the oceans and affecting plankton growth.

The storms can be severe. In 2018 more than 125 people died and 200 were injured by a high-velocity dust storm in northern India. Even in Europe large areas can be covered in orange sand and dust from the Sahara.

Hesham El-Askary, professor of earth systems science and remote sensing at Chapman University in California, said: “There is a need for more accurate real-time observations of dust properties and for understanding dust triggering mechanisms, seasonal variabilities, and transport dynamics to assist mitigation of windblown dust consequences in many applications. These include human health, weather, solar and wind energy systems, aviation, highway safety and urban development.”

Higher cyclone intensity

The Asia Pacific Disaster Report 2019, released in August, suggests that the impacts of climate change differ by sub-region: “Temperature increase is likely to cause a rise in the number and duration of heat waves and droughts . . . Climate change is also expected to increase cyclone intensity, with serious threats along the coastal areas of countries in south-east Asia.”

A complex sequence of climate and weather disasters such as drought, SDS, desertification and floods is on the rise in arid and semi-arid sub-regions of south-west and central Asia, the report said. And, as indicated clearly in the recent IPCC report on global warming of 1.5°C, the decrease in soil moisture will increase the frequency and intensity of sand and dust storms in south, south-west and central Asia.

A recent example was the powerful dust storm that swept over parts of Iran, Afghanistan and Pakistan in May 2018. There was also a toxic salt storm from the Aral Sea that hit northern Turkmenistan and western Uzbekistan.

The storms then moved through Iran, Afghanistan, Pakistan and north-west India and collided with the pre-monsoon weather, including thunderstorms and rain, affecting a wide area and causing the loss of hundreds of lives.

By Nivedita Khandekar