Jakarta:

Indonesia is using a weather modification technique known as cloud seeding around the site of its future capital to reduce intense rains that have hampered construction of the new city, a weather agency official said on Friday.

The planned city of Nusantara is set to begin operating on August 17, replacing traffic-clogged and sinking Jakarta as Indonesia’s new capital.

But contractors, whose work building the city has been hampered by daily rains, asked authorities to carry out a weather-modifying operation, said Tri Handoko Seto, a senior official at Indonesia’s Meteorological, Climatological and Geophysical agency (BMKG).

“They submitted a request to carry out a weather modification operation so that the rain that occurred every day can be diverted to another place, eliminated in a certain area, or at least be reduced,” Seto told AFP.

Cloud seeding, which introduces tiny particles or chemicals to manipulate existing clouds, has gained popularity worldwide as a way to induce rain to combat drought or boost local water supplies.

But scientists say the technique cannot create weather — nor can it trigger rainfall at the scale observed in countries such as Germany and the United States.

The cloud seeding operation around Nusantara began last week and is due to end on Sunday, followed by an evaluation to determine whether it needs to be continued, Seto said.

It is the first time authorities have used cloud seeding around the planned city to reduce rainfall, he said.

Flooding and landslides are common during the vast archipelago’s six-month rainy season and the BMKG has forecast the downpours around Nusantara will last until August.

The Indonesian government aims to have 1.9 million people living in Nusantara by 2045, importing a wave of human and industrial activity into the heart of Borneo.

Environmentalists have warned that the planned city will speed up deforestation in one of the world’s largest stretches of tropical rainforest.

Thousands of civil servants are expected to move to the city in September to begin work but Jakarta’s plan has already been delayed by several months due to slow construction.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

A leading weather experts has warned of “weather wars” between countries if cloud seeding gets out of hand. In a statement, Johan Jaques, a senior meteorologist at environmental technology company KISTERS, has warned if unintended consequences when technology is used to alter the weather. The comment comes as theories claiming Dubai’s torrential rainfall was caused by cloud seeding are doing the rounds on the internet. The practice, in which planes inject clouds with chemicals, was introduced in the 1940s especially in areas with little rainfall, or in case of prolonged dry spell.

But several experts don’t agree with the theory that cloud seeding was responsible, and the theory has caused a debate in the community.

Still, Mr Jaques thinks there could be diplomatic consequences and subsequent “weather wars” is cloud seeding is allowed to proliferate.

“Cloud seeding aims to enhance and accelerate the precipitation process. Especially in areas which have not seen any rain over a long time, such intense precipitation can lead to infiltration excess flow, with potential flash floods as a result,” the meteorologist said in a statement, as per Newsweek.

“The Dubai floods act as a stark warning of the unintended consequences we can unleash when we use such technology to alter the weather. Additionally, we have little control over the aftermath of cloud seeding. Where exactly is it going to be raining effectively? Using techniques such as cloud seeding to bring much-needed rainfall in one area can cause flash floods and droughts in another,” Mr Jaques further said.

There is no evidence to suggest that rain in Dubai was caused by cloud seeding. A UAE government agency that oversees the process has denied that any such operations took place before the storm.

The UAE state news agency late on Wednesday carried a statement from President Sheikh Mohammed bin Zayed Al Nahyan saying he had ordered authorities to assess the damage and provide support to families impacted by the storm.

A person stands surrounded by flood water caused by heavy rains, in Dubai, United Arab Emirates on April 17, 2024.
| Photo Credit: Reuters

The United Arab Emirates (UAE) struggled on April 18 to recover from the heaviest recorded rainfall ever to hit the desert nation, as its main airport worked to restore normal operations even as floodwater still covered portions of major highways and roads.

Dubai International Airport, the world’s busiest for international travel, allowed global carriers on April 18 morning to again fly into Terminal 1 at the airfield.

In the below post shared by the Dubai Media Office, a cat that has been clinging on to a car door is being saved by rescuers

“Flights continue to be delayed and disrupted, so we urge you to only come to Terminal 1 if you have a confirmed booking,” the airport said on the social platform X.

The long-haul carrier Emirates, whose operations had been struggling since the storm on April 16, had stopped travellers flying out of the UAE from checking into their flights as they tried to move out connecting passengers. Pilots and flight crews had been struggling to reach the airport given the water on roadways. But on April 18, they lifted that order to allow customers into the airport.

Others who arrived at the airport described hourslong waits to get their baggage, with some just giving up to head home or to whatever hotel would have them.

The UAE, a hereditarily ruled, autocratic nation on the Arabian Peninsula, typically sees little rainfall in its arid desert climate. However, a massive storm forecasters had been warning about for days blew through the country’s seven sheikhdoms.

By the end of April 16, more than 142 millimetres (5.59 inches) of rainfall had soaked Dubai over 24 hours. An average year sees 94.7 millimetres (3.73 inches) of rain at Dubai International Airport. Other areas of the country saw even more precipitation.

The UAE’s drainage systems quickly became overwhelmed, flooding out neighbourhoods, business districts and even portions of the 12-lane Sheikh Zayed Road highway running through Dubai.

The state-run WAM news agency called the rain “a historic weather event” that surpassed “anything documented since the start of data collection in 1949.” In a message to the nation late Wednesday, Emirati leader Sheikh Mohammed bin Zayed Al Nahyan, the ruler of Abu Dhabi, said authorities would “quickly work on studying the condition of infrastructure throughout the UAE and to limit the damage caused.” On April 18, people waded through oil-slicked floodwater to reach cars earlier abandoned, checking to see if their engines still ran. Tanker trucks with vacuums began reaching some areas outside of Dubai’s downtown core for the first time as well. Schools remain closed until next week.

Authorities have offered no overall damage or injury information from the floods, which killed at least one person.

“Crises reveal the strength of countries and societies,” Dubai’s ruler, Sheikh Mohammed bin Rashid Al Maktoum, wrote on X. “The natural climate crisis that we experienced showed the great care, awareness, cohesion and love for every corner of the country from all its citizens and residents.” The flooding sparked speculation that the UAE’s aggressive campaign of cloud seeding — flying small planes through clouds dispersing chemicals aimed at getting rain to fall — may have contributed to the deluge. But experts said the storm systems that produced the rain were forecast well in advance and that cloud seeding alone would not have caused such flooding.

Also read | Artificial rain to fix pollution remains a nebulous science

Jeff Masters, a meteorologist for Yale Climate Connections, said the flooding in Dubai was caused by an unusually strong low pressure system that drove many rounds of heavy thunderstorms.

Scientists also say climate change is responsible for more intense and more frequent extreme storms, droughts, floods and wildfires around the world. Dubai hosted the United Nations’ COP28 climate talks just last year.

Abu Dhabi’s state-linked newspaper The National in an editorial on April 18 described the heavy rains as a warning to countries in the wider Persian Gulf region to “climate-proof their futures.” “The scale of this task is more daunting that it appears even at first glance, because such changes involve changing the urban environment of a region that for as long as it has been inhabited, has experienced little but heat and sand,” the newspaper said.

A person walks towards cars stranded in flood water caused by heavy rains, in Dubai, United Arab Emirates, April 17, 2024.
| Photo Credit: Reuters

A storm hit the United Arab Emirates and Oman this week bringing record rainfall that flooded highways, inundated houses, grid-locked traffic and trapped people in their homes.

At least 20 people were reported to have died in the deluge in Oman while another person was said to have died in floods in the UAE that closed government offices and schools for days.

The storm had initially hit Oman on Sunday before it pounded the UAE on Tuesday, knocking out power and causing huge disruptions to flights as runways were turned into rivers.

ALSO READ | Artificial rain to fix pollution remains a nebulous science

In the UAE, a record 254 millimetres (10 inches) of rainfall was recorded in Al Ain, a city bordering Oman. It was the largest ever in a 24-hour period since records started in 1949.

Did cloud seeding cause the storm?

Rainfall is rare in the UAE and elsewhere on the Arabian Peninsula, that is typically known for its dry desert climate. Summer air temperatures can soar above 50 degrees Celsius.

But the UAE and Oman also lack drainage systems to cope with heavy rains and submerged roads are not uncommon during rainfall.

Following Tuesday’s events, questions were raised whether cloud seeding, a process that the UAE frequently conducts, could have caused the heavy rains.

Cloud seeding is a process in which chemicals are implanted into clouds to increase rainfall in an environment where water scarcity is a concern.

The UAE, located in one of the hottest and driest regions on earth, has been leading the effort to seed clouds and increase precipitation.

But the UAE’s meteorology agency told Reuters there were no such operations before the storm.

What about climate change?

The huge rainfall was instead likely due to a normal weather system that was exacerbated by climate change, experts say.

A low pressure system in the upper atmosphere, coupled with low pressure at the surface had acted like a pressure ‘squeeze’ on the air, according to Esraa Alnaqbi, a senior forecaster at the UAE government’s National Centre of Meteorology.

That squeeze, intensified by the contrast between warmer temperatures at ground level and colder temperatures higher up, created the conditions for the powerful thunderstorm, she said.

The “abnormal phenomenon” was not unexpected in April as when the season changes the pressure changes rapidly, she said, adding that climate change also likely contributed to the storm.

Climate scientists say that rising global temperatures, caused by human-led climate change, is leading to more extreme weather events around the world, including intense rainfall.

“Rainfall from thunderstorms, like the ones seen in UAE in recent days, sees a particular strong increase with warming. This is because convection, which is the strong updraft in thunderstorms, strengthens in a warmer world,” said Dim Coumou, a professor in climate extremes at Vrije Universiteit Amsterdam.

Cannot create clouds from nothing

Friederike Otto, a senior lecturer in climate science at Imperial College London, said rainfall was becoming much heavier around the world as the climate warms because a warmer atmosphere can hold more moisture. It was misleading to talk about cloud seeding as the cause of the heavy rainfall, she said.

“Cloud seeding can’t create clouds from nothing. It encourages water that is already in the sky to condense faster and drop water in certain places. So first, you need moisture. Without it, there’d be no clouds,” she said.

Global warming has resulted in “extraordinarily” warm water in the seas around Dubai, where there is also very warm air above, said Mark Howden, Director at the Australian National University’s Institute for Climate, Energy & Disaster Solutions.

“This increases both potential evaporation rates and the capacity of the atmosphere to hold that water, allowing bigger dumps of rainfall such as what we have just seen in Dubai.”

Gabi Hegerl, a climatologist at Edinburgh University, said that extreme rainfall, like in the UAE and Oman, was likely to get worse in many places due to the effects of climate change.

When conditions are perfect for really heavy rain, there’s more moisture in the air, so it rains harder. This extra moisture is because the air is warmer, which is because of human-caused climate change, she said.

A person walks towards cars stranded in flood water caused by heavy rains, in Dubai, United Arab Emirates, April 17, 2024.
| Photo Credit: Reuters

A storm hit the United Arab Emirates and Oman this week bringing record rainfall that flooded highways, inundated houses, grid-locked traffic and trapped people in their homes.

At least 20 people were reported to have died in the deluge in Oman while another person was said to have died in floods in the UAE that closed government offices and schools for days.

Also read | Artificial rain to fix pollution remains a nebulous science

The storm had initially hit Oman on Sunday before it pounded the UAE on Tuesday, knocking out power and causing huge disruptions to flights as runways were turned into rivers.

In the UAE, a record 254 millimetres (10 inches) of rainfall was recorded in Al Ain, a city bordering Oman. It was the largest ever in a 24-hour period since records started in 1949.

Did cloud seeding cause the storm?

Rainfall is rare in the UAE and elsewhere on the Arabian Peninsula, that is typically known for its dry desert climate. Summer air temperatures can soar above 50 degrees Celsius.

But the UAE and Oman also lack drainage systems to cope with heavy rains and submerged roads are not uncommon during rainfall.

Following Tuesday’s events, questions were raised whether cloud seeding, a process that the UAE frequently conducts, could have caused the heavy rains.

Cloud seeding is a process in which chemicals are implanted into clouds to increase rainfall in an environment where water scarcity is a concern.

The UAE, located in one of the hottest and driest regions on earth, has been leading the effort to seed clouds and increase precipitation.

But the UAE’s meteorology agency told Reuters there were no such operations before the storm.

What about climate change?

The huge rainfall was instead likely due to a normal weather system that was exacerbated by climate change, experts say.

A low pressure system in the upper atmosphere, coupled with low pressure at the surface had acted like a pressure ‘squeeze’ on the air, according to Esraa Alnaqbi, a senior forecaster at the UAE government’s National Centre of Meteorology.

That squeeze, intensified by the contrast between warmer temperatures at ground level and colder temperatures higher up, created the conditions for the powerful thunderstorm, she said.

The “abnormal phenomenon” was not unexpected in April as when the season changes the pressure changes rapidly, she said, adding that climate change also likely contributed to the storm.

Climate scientists say that rising global temperatures, caused by human-led climate change, is leading to more extreme weather events around the world, including intense rainfall.

“Rainfall from thunderstorms, like the ones seen in UAE in recent days, sees a particular strong increase with warming. This is because convection, which is the strong updraft in thunderstorms, strengthens in a warmer world,” said Dim Coumou, a professor in climate extremes at Vrije Universiteit Amsterdam.

Cannot create clouds from nothing

Friederike Otto, a senior lecturer in climate science at Imperial College London, said rainfall was becoming much heavier around the world as the climate warms because a warmer atmosphere can hold more moisture. It was misleading to talk about cloud seeding as the cause of the heavy rainfall, she said.

“Cloud seeding can’t create clouds from nothing. It encourages water that is already in the sky to condense faster and drop water in certain places. So first, you need moisture. Without it, there’d be no clouds,” she said.

Global warming has resulted in “extraordinarily” warm water in the seas around Dubai, where there is also very warm air above, said Mark Howden, Director at the Australian National University’s Institute for Climate, Energy & Disaster Solutions.

“This increases both potential evaporation rates and the capacity of the atmosphere to hold that water, allowing bigger dumps of rainfall such as what we have just seen in Dubai.”

Gabi Hegerl, a climatologist at Edinburgh University, said that extreme rainfall, like in the UAE and Oman, was likely to get worse in many places due to the effects of climate change.

When conditions are perfect for really heavy rain, there’s more moisture in the air, so it rains harder. This extra moisture is because the air is warmer, which is because of human-caused climate change, she said.

A cloud seeding experiment carried out in Solapur city, which falls on the leeward side of the Western Ghats and hence gets low rainfall — 384 mm and 422 mm of total rainfall during the period June to September 2018 and 2019, respectively — was able to achieve 18% relative enhancement in rainfall, which is approximately 8.67mm more rainfall. The relative enhancement of accumulated rainfall was seen over two hours after seeding the clouds. In all, the total enhancement of water availability through cloud seeding experiments was 867 million litres. The results of the study were published recently in the journal Bulletin of the American Meteorological Society.

The experiment — Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX phase-4) — was a scientific investigation conducted in Solapur city during the summer monsoon period of 2018 and 2019. The primary objective was to investigate the efficacy of hygroscopic seeding in deep convective clouds and to develop a cloud seeding protocol. The experiment used two aircraft for studying various cloud parameters and for seeding the clouds.

The study found that cloud seeding is an effective strategy for enhancing rainfall in a region under suitable conditions. A randomised seeding experiment was undertaken to study the effectiveness of cloud seeding in producing rainfall. In total 276 convective clouds were chosen, and 150 were seeded while the remaining 122 clouds were not seeded. “In our previous work we have found certain characteristics in a cloud such as the liquid water content in the cloud, the vertical motion in the cloud, which is an indicator of the growth of the cloud, will help inform us if the cloud will rain or not. Based on several criteria we know if a convective cloud has a potential to rain as all clouds cannot rain,” she says. Convective clouds with a depth of over one kilometre and likely to evolve into deep cumulus clouds were targeted.

“We must indicate that the availability of a large number of samples (150/122 seed/no-seed) is a testimony to the rainfall enhancement through hygroscopic seeding with the physical conditions set in CAIPEEX,” the authors write.

“The seeded clouds produced more rainfall than the unseeded clouds,” Dr. Thara Prabhakaran from the Indian Institute of Tropical Meteorology, Pune and the corresponding author of the paper tells The Hindu.

Calcium chloride flare was used for seeding the clouds. A cloud seeding flare releases these particles when triggered. The seeding was done at the base of the warm convective clouds and at a time when the clouds were in their growing stage so that the seed particles could enter the clouds with minimum dispersion. “The convective cloud bases are found at 500-1,500 metres altitude during the summer monsoon period and around 2,000 metres or more altitude during the monsoon break periods, which depends on the moisture content in the lower atmosphere,” Dr. Prabhakaran says. “Since the clouds are found at lower heights, the base of the convective clouds is warm, around 15 degrees C.”

“But cloud seeding alone cannot mitigate droughts but can help produce 18% more rainfall and partially address water requirements,” says Dr. M. Rajeevan, former secretary, Ministry of Earth Science, and a co-author of the paper. Undertaking cloud seeding as catchment-scale projects can possibly help in managing drought conditions.

“The study was carried for two years to first study and understand the microphysics and characteristics of convective clouds that can be targeted to enhance rainfall. The work provides elaborate protocols and technical guidance to plan and conduct cloud seeding in India,” he says. The two-year study has helped develop a high-resolution numerical model that can help stakeholders to identify target locations, clouds that can be seeded, and a suitable seeding strategy to enhance rainfall in an area.

One of the most important findings of the study was that not all cumulus clouds produce rainfall when cloud seeding is done. “We found 20-25% of cumulus clouds produce rainfall if cloud seeding is done correctly. The microphysics of clouds vary widely and so not all clouds produce rainfall through cloud seeding,” says Dr. Rajeevan.

“Though the relative enhancement of rainfall was 46% as measured by automatic rain gauges, the actual increase in rainfall over a 100 sq.km area was only 18%,” says Dr. Prabhakaran.

“We estimated the cost-benefit ratio and found the approximate cost of producing water through cloud seeding was 18 paisa per litre. It was a research experiment and so we hired two aircraft from outside India for seeding the clouds. The cost will drop by more than 50% if we use indigenous seeding aircraft,” says Dr. Prabhakaran.

In places like Solapur where water is supplied only once in three days, the availability of additional water through cloud seeding will be immensely beneficial.