Why is it in the News?

The UAE recorded the heaviest rain ever after a severe thunderstorm hit the country on April 15, killing at least one person, causing damage to homes and businesses, and bringing air travel to a standstill in Dubai.

What Led to the Heavy Rains in Dubai?

• The primary reason for these heavy rains was a storm system, which was passing through the Arabian peninsula and moving across the Gulf of Oman.
• According to a different report, rains could have been exacerbated by cloud seeding, a process of spraying salt mixtures in clouds that would result in condensation of the cloud and eventually cause rainfall.
  • Several reports quoted meteorologists at the National Center for Meteorology as saying they flew six or seven cloud-seeding flights before the rains.

Is climate change responsible for the event?

• Some experts have suggested that the soaring global temperatures could also be behind the event.
• Higher temperatures cause evaporation of water not only from land but also oceans and other water bodies, meaning a warmer atmosphere holds more moisture.
• Studies have found that for every 1 degree Celsius rise in average temperature, the atmosphere can hold about 7% more moisture.
• This makes storms more dangerous as it leads to an increase in precipitation intensity, duration, and/or frequency, which ultimately can cause severe flooding.
• While the average global temperature on the Earth has increased by at least 1.1 degrees Celsius since 1850, the UAE has witnessed an increase of almost 1.5 degrees Celsius in the past 60 years.
  • The increase in temperatures is mainly caused by the rise of heat-trapping greenhouse gas (GHG) emissions since the Industrial Revolution.
• However, it is extremely difficult to attribute any particular extreme weather event to climate change.
• It is because there are multiple factors, like patterns of natural climate variability, such as El Niño and La Niña, that contribute to such events.

What is Cloud Seeding?

• Cloud seeding is a type of weather modification where substances like silver iodide or dry ice are dispersed into clouds to encourage precipitation, such as rain or snow.
• In countries like the UAE, where temperatures are high and annual rainfall is minimal, cloud seeding is employed to alleviate pressure on limited groundwater sources by enhancing precipitation.

What is UAE's cloud seeding programme?

• The UAE initiated its cloud seeding program in the late 1990s, making it one of the first Middle Eastern countries to use this technique.
• Collaborative research with institutions like the National Center for Atmospheric Research (NCAR) and NASA has bolstered their efforts.

How does cloud seeding work?

• Cloud seeding is a technique where “seeding agents" such as silver iodide or salt are introduced into clouds to stimulate condensation and trigger rainfall.
• Weather forecasters monitor atmospheric conditions and identify suitable clouds for seeding based on precipitation patterns.
  • This technique can increase rainfall by up to 30-35 percent in clear conditions and 10-15 percent in more humid conditions.

What is the environmental impact of cloud seeding?

• Cloud seeding alters the precipitation patterns of a region/locality.
  • This may negatively impact neighboring ecosystems, which were to receive rain for the seeded clouds originally.
• Introducing seeding agents might impact the natural hydrological cycle as it may change the natural soil moisture levels, groundwater recharge, and river flows.
• Some experts worry about the potential for silver toxicity if cloud seeding becomes widespread.
  • Silver iodide is a common seeding agent.
  • Silver toxicity could pose risks to aquatic life and soil health.
• Therefore, even with the promise cloud seeding holds, responsible stewardship and thorough evaluation of its environmental impacts are crucial.