Oceans are warmer, higher and more acidic, climate report warns

May 18 (Reuters) – The world’s oceans in 2021 reached their warmest and most acidic levels on record, while melting ice caps helped push sea levels to new highs, said Wednesday the World Meteorological Organization (WMO).

The oceans experienced their most striking extremes when the WMO detailed a series of unrest caused by climate change in its annual “State of the Global Climate” report.

“Our climate is changing before our eyes. Heat trapped by man-made greenhouse gases will warm the planet for many generations to come,” WMO Secretary-General Petteri Taalas said in a statement.

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The WMO report follows the latest UN climate assessment, which warned that humanity must drastically reduce its greenhouse gas emissions or face increasingly catastrophic changes in the global climate. Read more

Levels of climate-warming carbon dioxide and methane in the atmosphere in 2021 surpassed previous records, the WMO said.

Globally, the average temperature last year was 1.11 degrees Celsius above the pre-industrial average – as the world approaches the 1.5C threshold above which the effects of global warming should become drastic. Read more

Last year’s temperatures were slightly temperate compared to 2020 due to the cooling effects of La Nina in the Pacific, although the year was still among the seven warmest years on record.

“It’s only a matter of time before we see another hottest year on record,” Taalas said.

The oceans bear much of the brunt of warming and emissions. Bodies of water absorb about 90% of the Earth’s accumulated heat and 23% of carbon dioxide emissions from human activity.

The ocean has warmed significantly faster over the past 20 years, reaching a new high in 2021, and is expected to get even warmer, the report said. This change would likely take centuries or millennia to reverse, he noted.

The ocean is also now its most acidic in at least 26,000 years, as it absorbs and reacts with more carbon dioxide in the atmosphere.

Sea level has risen 4.5 centimeters (1.8 inches) over the past decade, with the annual rise from 2013 to 2021 more than doubling from 1993 to 2002.

The WMO has also listed extreme heat waves, wildfires, floods and other climate-related disasters around the world, noting reports of more than $100 billion in damage.

The continental United States experienced its hottest summer ever, with hundreds of heat-related deaths recorded. The Dixie Fire burned 3,900 square kilometers (1,500 square miles), making it the largest wildfire on record in California.

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Reporting by Jake Spring; Editing by Katy Daigle and Lisa Shumaker

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