On Thursday, the National Oceanic and Atmospheric Administration distanced itself from the designation, compiled by the University of Maine’s Climate Reanalyzer, which uses satellite data and computer simulations to measure the world’s condition.

That metric showed the earth’s average temperature on Wednesday remained at an unofficial record high of 17.18 degrees Celsius, set the day before.

For the seven-day period ending Wednesday, the daily average temperature was .04C higher than any week in 44 years of record-keeping, according to Climate Reanalyzer data.

Although the figures are unofficial, many scientists agree they indicate climate change is reaching uncharted territory.

The White House said the data showed the need for legislative action.

“The alarming extreme weather events impacting millions of Americans underscore the urgency of President Biden’s climate agenda and the absurdity of continued efforts by Republican lawmakers to block and repeal it,” spokesman Abdullah Hasan said.

NOAA, whose figures are considered the gold standard in climate data, said in a statement on Thursday it cannot validate the unofficial numbers.

It noted that the reanalyzer uses model output data, which it called “not suitable” as substitutes for actual temperatures and climate records.

The agency monitors global temperatures and records on a monthly and an annual basis, not daily.

“We recognise that we are in a warm period due to climate change, and combined with El Nino and hot summer conditions, we’re seeing record warm surface temperatures being recorded at many locations across the globe,” the statement said.

United Nations Secretary-General Antonio Guterres said the latest numbers helped prove “that climate change is out of control”.

“If we persist in delaying key measures that are needed, I think we are moving into a catastrophic situation, as the last two records in temperature demonstrates,” he said.

More frequent and more intense heat waves are disrupting life around the world and causing life-threatening temperatures.

In Timbuktu, Mali – at the gateway to the Sahara Desert – 50-year-old Fatoumata Arby said this kind of heat was new.

“Usually, at night it’s a bit cool even during the hot season but this year, even at night, it’s been hot – I’ve never seen anything like it,” said Arby, who rarely leaves her hometown.

“I’ve been having heart palpitations because of the heat.

“I’m starting to think seriously that I’m going to leave Timbuktu.”

Last week, Egypt experienced one of its many summer heatwaves, with temperatures soaring above 37.7C, according to the country’s national weather forecaster.

To combat heat and humidity, children on Thursday frolicked in the Nile River while pedestrians hunted the shade.

People are also feeling the effects in Nouakchot, Mauritania’s capital city, on the shores of the Atlantic.

For Abdallahi Sy, a 56-year-old farmer who works in the market gardens, environmental changes have reduced his already meagre income.

“I have a small shelter built from wooden poles and scraps of cloth,” said Sy, who tries to work from 6am to 11am.

“I take refuge there when the heat becomes unbearable.”

He cited a scarcity of water and quality feed for livestock as causes for illness and even miscarriage among animals.

“It is clear that we are facing profound changes in our environment,” he said.

“The earth is becoming less fertile and less generous.”

Overall, one of the largest contributors to this week’s heat records is an exceptionally mild winter in the Antarctic.

Parts of the continent and nearby ocean were 10C to 20C higher than averages from 1979 to 2000.

“Temperatures have been unusual over the ocean and especially around the Antarctic this week because wind fronts over the Southern Ocean are strong pushing warm air deeper south,” said Raghu Murtugudde, professor of atmospheric, oceanic and earth system science at the University of Maryland and visiting faculty at the Indian Institute of Technology, Bombay.

Chari Vijayaraghavan, a polar explorer and educator who has visited the Arctic and Antarctic regularly for the past 10 years, said global warming was obvious at both poles.

He said it threatened the region’s wildlife and was driving the ice melt that raises sea levels.

“Warming climates might lead to increasing risks of diseases such as the avian flu spreading in the Antarctic that will have devastating consequences for penguins and other fauna in the region,” Vijayaraghavan said.

Katharine Hayhoe, The Nature Conservancy chief scientist and a climate scientist at Texas Tech, said decisive action was needed to achieve net zero.

“This is one more reminder of the inexorable upward trend that will only be halted by decisive actions to wean ourselves off fossil fuels, invest in nature, and achieve net zero,” she said.