Japan, which has just endured its hottest summer on record, said Friday it had also last month recorded the warmest sea temperatures since it started gathering comparable data 25 years ago.
Ocean surface temperatures in much of the archipelago's Pacific Ocean and Sea of Japan waters reached more than 25 degrees centigrade (77 degrees Fahrenheit) in August, said the Japan Meteorological Agency.
The average sea temperature was the hottest recorded since 1985 when the agency started a new measuring system, and was also a record 1.2 degrees centigrade above the average for the 1971-2000 period.
"When examining the earlier data also, I would say global warming is one of the factors behind the warmest recorded sea waters," said an agency official.
Scientists warn that the greenhouse effect caused by heat-trapping gases in the atmosphere is raising global temperatures, melting the planet's ice caps and triggering more severe weather events such as storms and floods.
Japan this year experienced its hottest summer since records began in 1898, with thousands of people taken to hospital with heatstroke. The average temperature for June to August was 1.64 degrees centigrade above average.
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