Bay of Bengal recorded nearly 30% higher sea level rise over global average; east and north India have warmed more than rest of country
The Asian continent was the world’s most disaster-prone region in 2023. Floods and storms caused the highest number of reported casualties and economic losses in Asia, while the impact of heatwaves became more severe, according to a report launched by the World Meteorological Organization (WMO) on April 23 in Bangkok.
The WMO report — The State of the Climate in Asia 2023 — is based on inputs from National Meteorological and Hydrological Services; United Nations partners and a network of climate experts.
It also showed that sea level rise in the Bay of Bengal off India’s eastern coast was the second-highest in the region last year, being nearly 30 per cent above the global average. The rise of temperature in eastern and northern India had been highest in India, according to the document.
The analysis also pointed out that the long-term warming trend has been accelerating, with extreme heat becoming more severe and causing glaciers to melt, thus threatening future water security. Meanwhile, sea surface temperatures and ocean heat have hit record highs.
Read DTE Coverage: Cyclone Mocha rocks Myanmar, spares Bangladesh
“Many countries in the region experienced their hottest year on record in 2023, along with a barrage of extreme conditions, from droughts and heatwaves to floods and storms. Climate change exacerbated the frequency and severity of such events, profoundly impacting societies, economies, and, most importantly, human lives and the environment …,” observed WMO Secretary-General Celeste Saulo about the findings.
“Yet again, in 2023, vulnerable countries were disproportionately impacted. For example, tropical cyclone Mocha, the strongest cyclone in the Bay of Bengal in the last decade, hit Bangladesh and Myanmar…,” said Armida Salsiah Alisjahbana, executive secretary of the Economic and Social Commission for Asia and the Pacific (ESCAP), which partnered in producing the report.
“The report emphasises the need for robust climate finance mechanisms to scale up adaptation and address loss and damage in developing countries of Asia, which bear the brunt of climate-related adversaries,” Harjeet Singh, global climate activist, told Down To Earth (DTE).
Soaring Celsius & melting glaciers
“The annual mean near-surface temperature over Asia in 2023 was the second-highest on record, 0.91°C … above the 1991-2020 average and 1.87 °C … above the 1961-1990 average. Particularly high average temperatures were recorded from western Siberia to central Asia and from eastern China to Japan,” the report read.
Even the sea was not spared from rising mercury. “The sea surface in the areas of the Kuroshio current system (west side of the North Pacific Ocean basin), the Arabian Sea, the Southern Barents Sea, the Southern Kara Sea, and the South-Eastern Laptev Sea is warming more than three times faster than the globally averaged sea surface temperature,” according to the WMO analysis.
Warming of the upper-ocean (0 m-700 m) is particularly strong in the North-Western Arabian Sea, the Philippine Sea and the seas east of Japan, more than three times faster than the global average; it further stated.
Read Is the Arabian Sea no longer pacific?
Marine heatwaves — prolonged periods of extreme heat in the ocean — had occurred in a large area of the Arctic Ocean, in the Eastern Arabian Sea and the Northern Pacific, and lasted three to five months.
The report links the warming of the sea with rising greenhouse gas emissions.
“Due to emissions of heat-trapping greenhouse gases resulting from human activities, the global ocean has warmed. It has taken up more than 90% of the excess heat in the climate system, making climate change irreversible on centennial to millennial timescales. Ocean warming contributes to about 40% of the observed global mean sea-level rise and alters ocean currents … also indirectly alters storm tracks, increases ocean stratification and can lead to changes in marine ecosystems” the compendium explained.
The document pointed out that the High Mountain Asia region, centred on the Tibetan Plateau and containing the largest volume of ice outside of the polar regions with glaciers covering an area of approximately 100,000 sq km, is under threat.
Read Hindu Kush Himalaya is a ‘biosphere on the brink’: ICIMOD
“Over the last several decades, most of these glaciers have been retreating, and at an accelerating rate (with) 20 out of 22 observed glaciers in the High Mountain Asia region showed continued mass loss,” the analysis noted, adding that record-breaking high temperatures and dry conditions in the eastern Himalayas and most of the Tien Shan, had exacerbated mass loss for most glaciers.
The analysis also pointed out how changing climate played a key role in triggering a glacial lake outburst flood (GLOF) through the Teesta river, killing many in Sikkim and northern West Bengal.
Read DTE Coverage: Sikkim Disaster 2023, as it happened
“Heatwaves and their impacts on water resources will increase manifold in the near future. Shrinking water resources can lead to conflict situations within a country, endangering national security,” Sanjay Vashist, director of Climate Action Network South Asia (CANSA) told DTE.
Less precipitation & killer floods
Precipitation was below normal in 2023 across almost the entire Asian region.
Large parts of the Turan lowland (Turkmenistan, Uzbekistan, Kazakhstan), the Hindu Kush (Afghanistan, Pakistan), the Himalayas, the Ganga and lower course of the Brahmaputra (India and Bangladesh), the Arakan mountains (Myanmar) and the lower course of the Mekong had below normal rain, according to the report.
It further added that southwest China suffered a drought, and below-normal precipitation levels were recorded nearly every month of 2023, with rains linked to the Indian summer monsoon being below average.
Read China faces its longest, most severe drought ever recorded
However, despite overall less precipitation, over 80 per cent of reported hydrometeorological hazards in Asia were flood and storm events in 2023, leading to more than 2,000 fatalities and directly affecting 9 million people, the analysis confirmed.
“Specifically, floods were the leading cause of death in reported events in 2023 by a substantial margin. In India, Yemen, and Pakistan, floods were the natural hazard event,” it stated.
The report linked the high intensity of flooding in 2023 with the record-breaking sudden rainfall triggered by cyclones impacting the region. “… a total of 17 … tropical cyclones formed over the western North Pacific Ocean and the South China Sea (triggering) major impacts and record-breaking rainfall in countries including China, Japan, the Philippines and Republic of Korea,” the report found. It further added that in the North Indian Ocean basin, extremely severe cyclonic storm Mocha caused widespread destruction and 156 reported deaths.
“In June, July and August, several floods and storm events resulted in more than 600 reported deaths across India, Pakistan, and Nepal,” the analysis pointed out. It reminded that the Hong Kong Observatory Headquarters recorded an hourly rainfall total of 158.1 mm on September 7, the highest since records began in 1884, because of a typhoon; ditto in Vietnam, Saudi Arabia, United Arab Emirates, Yemen, and Russian Federation
India one of the biggest sufferers
“In India, severe heat waves in April and June resulted in about 110 reported fatalities due to heatstroke. A major and prolonged heatwave affected much of South-East Asia in April and May, extending as far west as Bangladesh and eastern India …with record breaking temperatures” confirmed the report.
A close look at the report showed that the average temperature in 2023, compared to the average of 1991-2021, increased in the range of 0.5 to 1 degrees Celsius in the eastern part of India especially West Bengal, parts of Jharkhand, Bihar and the northern states like Uttarakhand, Uttar Pradesh, Himachal Pradesh, Delhi, Rajasthan, Jammu and Kashmir, Ladakh and Punjab. The rest of India did not show a comparitive rise.
The sea level rise, considering the period from January 1993 to May 2023 as calculated through satellite measurements, was found to be 4.44 mm per year in the Bay of Bengal, about 30 per cent higher than global average of 3.4 mm; and only second to that experienced in the western tropical Pacific region, which rose at a level of 4.53 mm per year. Incidentally, the Sundarbans, on the coast of West Bengal, has been found to have the highest sea level rise in India, as intimated by the Centre during discourse in the outgoing parliament (2019-2024).
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