Summer 2023 Was the Hottest in 2,000 Years, Study Says

A child cools off at a water supply line as temperatures rise in Karachi, Pakistan, 13 May 2024. (EPA)
A child cools off at a water supply line as temperatures rise in Karachi, Pakistan, 13 May 2024. (EPA)
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Summer 2023 Was the Hottest in 2,000 Years, Study Says

A child cools off at a water supply line as temperatures rise in Karachi, Pakistan, 13 May 2024. (EPA)
A child cools off at a water supply line as temperatures rise in Karachi, Pakistan, 13 May 2024. (EPA)

Last summer, as wildfires swept across the Mediterranean, roads buckled in Texas and heatwaves strained power grids in China, it was not just the warmest summer on record, but the hottest one in some 2,000 years, new research has found.

European scientists last year established that the period from June through August was the warmest in records dating back to 1940 - a clear sign of climate change fueling new extremes.

But the summer heat of 2023 in the Northern Hemisphere also eclipses records over a far longer time horizon, a study in the journal Nature found on Tuesday.

"When you look at the long sweep of history, you can see just how dramatic recent global warming is," said study co-author Jan Esper, a climate scientist at Johannes Gutenberg University in Germany.

Summer 2023 saw land temperatures between 30 and 90 degrees North of latitude reach 2.07 degrees Celsius (3.73 degrees Fahrenheit) higher than pre-industrial averages, the study said.

Scientists used meteorological station records dating back to the mid-1800s combined with tree rings from thousands of trees across nine sites in the Northern Hemisphere, to recreate what annual temperatures looked like in the distant past.

Last summer, they found, was 2.2 C warmer (4 F) than the estimated average temperatures for the years of 1 to 1890, based on these tree ring proxies.

Scientists with the European Union's Copernicus Climate Change Service said in January that 2023 was "very likely" to have been the warmest in the last 100,000 years.

However, Esper and a team of European scientists have refuted such claims. They argue the scientific methods of gleaning past climate information from sources such as lake and marine sediments and peat bogs, do not allow to draw out year-by-year comparisons for temperature extremes over such a vast time scale.

"We don't have such data," Esper said. "That was an overstatement."

The warming from rising greenhouse gas emissions caused by the burning of fossil fuels was amplified last summer by an El Nino climate pattern which generally leads to warmer global temperatures, Esper said.

"We end up with longer and more severe heatwaves and extended periods of drought," he said.



Latest Tests Show Seine Water Quality Was Substandard When Paris Mayor Took a Dip

 Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
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Latest Tests Show Seine Water Quality Was Substandard When Paris Mayor Took a Dip

 Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)

Tests results released Friday showed the water quality in the River Seine was slightly below the standards needed to authorize swimming — just as the Paris Olympics start.

Heavy rain during the opening ceremony revived concerns over whether the long-polluted waterway will be clean enough to host swimming competitions, since water quality is deeply linked with the weather in the French capital.

Paris Mayor Anne Hidalgo took a highly publicized dip last week in a bid to ease fears. The Seine will be used for marathon swimming and triathlon.

Daily water quality tests measure levels of fecal bacteria known as E. coli.

Tests by monitoring group Eau de Paris show that at the Bras Marie, E. coli levels were then above the safe limit of 900 colony-forming units per 100 milliliters determined by European rules on June 17, when the mayor took a dip.

The site reached a value of 985 on the day the mayor swam with Paris 2024 chief Tony Estanguet and the top government official for the Paris region, Marc Guillaume, joined her, along with swimmers from local swimming clubs.

At two other measuring points further downstream, the results were below the threshold.

The statement by Paris City Hall and the prefecture of the Paris region noted that water quality last week was in line with European rules six days out of seven on the site which is to host the Olympic swimming competitions.

It noted that "the flow of the Seine is highly unstable due to regular rainfall episodes and remains more than twice the usual flow in summer," explaining fluctuating test results.

Swimming in the Seine has been banned for over a century. Since 2015, organizers have invested $1.5 billion to prepare the Seine for the Olympics and to ensure Parisians have a cleaner river after the Games. The plan included constructing a giant underground water storage basin in central Paris, renovating sewer infrastructure, and upgrading wastewater treatment plants.