Sea surface temperatures and ocean heat
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.
In 2023, the area-averaged sea surface temperature anomalies were the warmest on record in the North-west Pacific Ocean. The Barents Sea is identified as a climate change hotspot because ocean surface warming has a major impact on sea-ice cover, and there is a feedback mechanism in which loss of sea-ice in turn enhances ocean warming because darker sea surfaces can absorb more solar energy than the highly reflective sea-ice.
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.
Marine heatwaves - prolonged periods of extreme heat that affect the ocean - occurred in a large area of the Arctic Ocean, in the Eastern Arabian Sea and the Northern Pacific, and lasted three to five months.
Extreme events
In 2023, over 80% of reported hydrometeorological hazards in Asia were flood and storm events, according to EM-DAT data. 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 which caused the greatest number of fatalities, highlighting the continuing high level of vulnerability of Asia to natural hazard events, especially floods.
In 2023, a total of 17 named tropical cyclones formed over the western North Pacific Ocean and the South China Sea. This was below average but there were still major impacts and record-breaking rainfall in countries including China, Japan, the Philippines and Republic of Korea.
In the North Indian Ocean basin, Extremely Severe Cyclonic Storm Mocha made landfall along the Rakhine Coast in Myanmar on 14 May, causing widespread destruction and 156 reported deaths.
Several extreme precipitation events took place in 2023. In June, July and August, several floods and storm events resulted in more than 600 reported deaths across India, Pakistan, and Nepal.
The Hong Kong Observatory Headquarters recorded an hourly rainfall total of 158.1 mm on 7 September, the highest since records began in 1884, as a result of a typhoon. Several stations in Vietnam observed record-breaking daily rainfall amounts in October.
Heavy rainfall led to flooding in Saudi Arabia and the United Arab Emirates in November.
Yemen also suffered heavy rainfall and resulting widespread flooding.
In August and early September 2023, the far eastern part of the Russian Federation suffered catastrophic flooding in one of the largest disasters in recent decades, affecting about 40 000 hectares of rural land.
Many parts of Asia experienced extreme heat events in 2023. Japan experienced its hottest summer on record. China experienced 14 high temperature events in summer, with about 70% of national meteorological stations exceeding 40℃ and 16 stations breaking their temperature records.
In India, severe heatwaves 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, and north to southern China, with record-breaking temperatures.
Challenges and opportunities
According to the WMO climate services checklist data, 82% of Member countries in the region provide data services to support disaster risk reduction.
However, currently less than 50% of National Meteorological and Hydrological Services (NMHSs) in the region provide tailored products for the disaster risk reduction community.
Therefore, there is an urgent need to advance these efforts and provide more tailored support and services to address strategies and interventions to effectively mitigate rising disaster risks.