Higher lightning strikes linked to climate change

As many as 18.5 million lightning strikes were recorded in India between April 1, 2020 and March 31, 2021, according to India’s second annual report on lightning released by the Lightning Resilient India Campaign (LRIC) recently. This is an increase of 34% compared to previous year; at least 13.8 million strikes were recorded between April 1, 2019 and March 31, 2020.

As highlighted by the Down to Earth (DTE) magazine, the LRIC study states that at least 1697 people died due to lightning between April 1, 2020 and March 31, 2021. Of this, 401 died in Bihar, followed by Uttar Pradesh (238 deaths) and Madhya Pradesh (228 deaths). At least 156 people died in Odisha, which accounted for over 13.5% of the total lightning strikes in 2020-21. The state witnessed over two million strikes during this period.

Lightning strikes increased in Punjab 331%, followed by Bihar (168%), Haryana (164%), Puducherry (117%), Himachal Pradesh (105%) and West Bengal (100%). But states like Odisha and Andhra Pradesh were able to reduce fatalities by almost 70% in a short time, the report noted. The lightning incidents recorded during the period revealed that seasonality of lightning was different for different states. Andhra Pradesh, for example, recorded maximum incidences in June 2019 and October 2019.

Bihar recorded the maximum incidences in September 2019; and Odisha in June 2019. It was thereby important that lightning risk management programme for each state was customized according to the seasonality, intensity and frequency of lightning, the report noted.

Within each state, the seasonality and severity may vary for different areas, namely, coastal, hilly, river basin, urban and industrial areas, flagged the annual report. The report has suggested that states should undertake lightning micro-zonation for the regions depending on their geography to handle the disaster and death risks better, the report suggested.

The LRIC is a joint initiative of the Climate Resilient Observing-Systems Promotion Council (CROPC), the National Disaster Management Authority, the India Meteorological Department (IMD), Union Ministry of Earth Science, World Vision India, UNICEF, among others. The campaign aims to reduce the number of deaths to less than 1200 a year by 2022.

The number of such days across India increased significantly every month progressively, the IMD and CROPC said in its report that was released in September 2019. There was, however, a minor decrease of four per cent between the financial year 2020 (April 1, 2019-March 31, 2020) and 2021 (April 1, 2020-March 31, 2021).

This decrease, the report claimed, was due to the dedicated efforts by the governments of the most-vulnerable states: Odisha, Andhra Pradesh and Bihar. However, 87 lives were lost in incidents of lightning strikes across Bihar on June 25, 2020.  The Annual Lightning Report 2020-2021 also contained the map of lightning strikes over India and all 37 states and Union territories. The rise in fatalities due to an increase in frequency and intensity lightning strikes prompted the IMD to start lightning forecasts from April 1, 2019.

The campaign, through multi-stakeholders engagement at national and state level with governments, academia, non-profits and communities, has been successful in bringing down deaths by more than 60% within two years, the report claimed.

The DTE report highlights another study published in Geophysical Research Letters in March 2021, too, which has established links between climate change and rising incidences of lightning in the Arctic region. The number of lightning strikes recorded during the summer months between 2010 and 2020 shot up from around 18,000 at the start of the decade to more than 150,000 by 2020, it said.  

Monitoring of lightning for climate science and services was limited. Hence, lightning was added to the Global Climate Observing System’s list of Essential Climate Variables in 2016. In 2017, Atmospheric Observation Panel for Climate was asked to create a task team. Experts then concluded that a majority of evidence on natural time scales showed an increase of lightning with warming, though that is not finally proven.

The main aim of the task team was to identify the potentials and challenges for lightning as climate variable and propose a plan on how to establish operational monitoring of lightning for climate applications.

The DTE report also points out that according to a pre-print accepted for journal Atmospheric Chemistry and Physics recently, the frequency and intensity of lightning strikes in India are expected to increase by 10% to 25% and 15% to 50% by the end of this century. Coastal areas may be at the highest risk.