Lightnings: The bombardment from heavens

Syed Tashfin Chowdhury | Published: May 11, 2018 21:33:37

It is inadvisable to go outdoors during a storm in recent times due to the increased number of lightning strikes, especially in rural areas. The rising death toll from thunderbolts led our government to declare it a natural disaster in 2016. With the intensity of lightning strikes increasing in our country, the reasons behind the disaster need to be identified so that proper remedial measures can be taken.

More than 80 people died in lightning strikes in different parts of the country during the first 10 days of May. That attests to the severity of the nature's curse. According to Disaster Forum, a Dhaka-based national disaster preparedness network of 70 different humanitarian and development agencies, research institutions and government departments, 76 more people died in lightning strikes during the period of January to April last.

During the period of 2010 to 2017, at least 2,029 people were killed in lightning strikes across Bangladesh, said Disaster Forum's member secretary Gawher Nayeem Wahra while talking to The Financial Express. He also pointed out that most lightning strikes took place in Chapainawabganj, Kishoreganj, Lalmonirhat, Sunamganj, Satkhira, Dinajpur and Brahmanbaria districts of the country. Since the Ministry of Disaster Management and Relief declared this vagary of nature a 'natural disaster' in 2016, if anyone died from a lighting strike, his/her family was likely to receive Tk 20,000 from the government.

In fact, the rate of lightning strikes has increased across the world. Severe lightning strikes and dust storms led to the loss of 125 lives in Uttar Pradesh, Rajasthan and Punjab of India last week. Over 80,000 lightning strikes were recorded during the storms in the affected areas, around 41,000 of which occurred in Andra Pradesh only. 

A 2017 study on lightning, conducted by Vaisala, a Finland-based maker of weather and environment monitoring equipment, found that out of nearly 8.76 billion lightning strikes tracked worldwide during 2013 to 2017, the most bolts had hit the USA. However, the National Oceanic and Atmospheric Administration (NOAA) reported that only 16 people were killed by thunderbolts in the entire USA in 2017. The number was 39 in 2016. The rise in the frequency of lightning strikes was predicted a few years earlier by a number of studies worldwide.

A 2014 study by the University of Berkeley, California had pointed out that the combined effect of precipitation and cloud buoyancy would generate 50 per cent more electrical discharges to the ground by the end of the century due to global warming.

The Intergovernmental Panel on Climate Change, the supreme authority in climate science, had said, "It is generally expected that lightning will increase in a warmer climate, although a study for the 2030 climate finds no global increase, but a shift from the tropics to mid-latitudes."

"Global warming is the reason," said Dr. A Atiq Rahman, Executive Director of Bangladesh Centre for Advanced Studies, while talking to The Financial Express. Mr Rahman pointed out that the global average surface temperature rose by 0.6 to 0.9 degrees Celsius (1.1 to 1.6° F) between 1906 and 2005. It more than doubled in the last 50 years, he said.

He referred to the Paris Agreement on climate change, where 195 countries had agreed to limit the global average temperature rise well below 2.0 degrees Celsius compared to the pre-industrial level, until the year 2100.

"However, all calculations show that it would be difficult to attain this as already the increase in global temperature has crossed 0.9 degrees Celsius. This is why the intensity of climate-related disasters is increasing," he said.

He has explained that due to the rising heat, there is more water vapour going up in the air. "This increases cloud formation. Thunder and lightning comes from Cumulonimbus clouds. These water and rain-bearing clouds have negative charges. A build-up of positive charge from the ground attracts the negative charge at the bottom of these clouds causing lightning," said Mr Rahman. He pointed out that the number of human casualties was increasing due to different reasons.

"Primarily, lightning strikes the highest point in a flat area. Earlier, there used to be tall trees near the fields, which attracted much of the lightning. Due to deforestation, the lightning bolts now hit other tall objects, mostly human beings," he said.

Mr Rahman also noted that farmers working on agricultural land usually fall victim to the disaster. "They wield metallic objects which are good conductors of electricity. Also, population growth is another reason behind the increase in such casualties," he said. Scientists found that fatalities from lightning were higher in developing countries. More than 70 per cent of thunderbolts that hit the earth every second take place in tropical and sub-tropical regions. The 2017 Vaisala study had found that the most lightning strikes happened in the USA, followed by north-western Australia, Paraguay, Uruguay and Columbia in South America, the Democratic Republic of Congo in Africa, India in South Asia and Sumatra and Malaysia of Southeast Asia. Russia, eastern European countries and much of Canada see a lower number of lightning strikes due to little contrast in temperatures in these areas.

As the rate of thunderbolts will continue to increase, mass awareness and proper measures to forecast lightning can help curb the number of casualties.

Atiq Rahman mentioned that in the past most buildings and structures in Bangladesh used to have lightning rods. As soon as a bolt hit the rod, a wire connected to it transferred the electricity into the earth thus protecting the structure and its inhabitants from any harm. He pointed out that the rods could be installed at new buildings and homes.

The Ministry of Disaster Management and Relief has been conducting awareness campaigns since 2017. The Meteorological Department has started providing instant forecasts giving more accurate location of strikes within 24 hours. Also, the Department of Disaster Management initiated a programme under which one million palm trees are being planted across the country in order to reduce the damage from lightning.

Only recently the disaster management ministry installed eight lightning detective sensors in Dhaka, Chattogram, Mymensingh, Panchagarh, Sylhet, Naogaon, Patuakhali and Khulna at a total cost of Tk 200 million.

Such sensors can provide more accurate details about the location and time for thunderbolts. Already such sensors had positive impacts on curbing casualties and other losses from lightning strikes in West Bengal and Andhra Pradesh of India and in some European countries.

Other tried and tested measures and practices applied by developed nations against the disaster can be replicated in Bangladesh. Additionally, better awareness and preparedness on the part of any individual and also at the collective level can help curb the rising death toll from the natural disaster.

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