Ocean and land temperatures continued their record-breaking spree in October. Sea surface and land temperatures have been at record highs for seven and five months respectively, data maintained by University of Maine’s Climate Reanalyzer shows.
Average sea surface temperatures were significantly high in October compared to the 1982-2011 mean and higher than any year since 1981 as per Climate Reanalyzer’s data. The trend started in April, a result of an intensifying El Nino in addition to global warming. Copernicus Marine’s data said that as of 20 October, sea surface temperature anomalies reached peaks of +3 to +5°C at various locations in the Mediterranean Sea.
September was the warmest September in the National Oceanic and Atmospheric Administration (NOAA’s) 174-year global climate record, NOAA said in a statement on October 13. September’s temperature propelled 2023 into the lead as the warmest year-to-date on record, according to scientists at NOAA’s National Centers for Environmental Information (NCEI). There was no let up in October . Climate Reanalyzer’s data indicated that air temperature was also higher than global average temperatures recorded since 1981. But, the ocean temperature anomalies were far higher than those recorded for air temperatures indicating that oceans are absorbing additional heat.
“Oceans absorb about 93% of the additional heat from global warming. This ocean heat emerges during warm water events like the El Nino, which has been active since spring this year. During an El Nino, the warm waters surface over the entire Pacific, hence the sea surface temperatures remain high. The water is exposed to the atmosphere above, thereby pumping up global temperatures and modifying weather everywhere. This is also reflected as marine heatwaves in the Indian Ocean, affecting the local weather and climate of the region. We had La Nina conditions during the last three years, and neutral conditions before that, due to which the warm ocean heat content didn’t surface for a long time,” explained Roxy Mathew Koll, climate scientist at Indian Institute of Tropical Meteorology.
“Temperatures are abnormally high. This could be the combined effect of increasing greenhouse gases and presence of El Niño. These abnormal temps are however not unexpected. These are as per the model predictions made in the beginning of the year. Consequences are heat waves over both land and ocean in the coming months and associated damages,” said M Rajeevan, climate scientist and former secretary, ministry of earth sciences.
The year-to-date average global surface temperature was the warmest on record at 1.10 degrees C above the 20th-century average of 14.1 degrees C. South America and Europe had their record-warmest such year to date, with Africa seeing its second warmest. According to NCEI’s Global Annual Temperature Outlook and data through September, there is now a greater than 99% probability that 2023 will rank as the warmest year on record.