Bangalore, India – Global temperatures fell only slightly after two days of record highs, making Tuesday only the second-hottest day ever recorded on Earth.
Europe’s Copernicus climate service estimated Tuesday’s global average temperature was 0.01 degrees Celsius (0.01 degrees Fahrenheit) lower than Monday’s record high of 17.16 C (62.8 F), which was 0.06 degrees Celsius (0.1 F) warmer than Sunday.
All three days were warmer than the hottest day yet documented on Earth, in 2023.
“The continued pace of record and near-record hottest days is concerning for three main reasons. First, heat kills. Second, the health impact of heat waves becomes much more severe when the phenomenon persists. Third, this year’s record hottest days are a surprise,” said Stanford University climate scientist Chris Field.
Field said high temperatures typically occur during El Niño years, a natural warming of the equatorial Pacific that causes extreme events around the planet, but the last El Niño ended in April.
These high temperatures, he noted, “underline the severity of the climate crisis.”
“This was probably the shortest record ever,” Copernicus director Carlo Buontempo said on Wednesday, as the agency estimated that Monday had surpassed Sunday’s mark. And he predicted that that mark would also be short-lived. “We are in uncharted territory,” he added.
Before 3 July 2023, the warmest day measured by Copernicus was 16.8ºC (62.2ºF) on 13 August 2016. In the past 13 months, that figure has been exceeded 59 times, according to Copernicus.
Humanity already lives “in a world that is already much warmer than before,” warned Buontempo.
“Unfortunately, people are going to die and those deaths are preventable,” said Kristie Ebi, a professor of public health and climate change at the University of Washington. “There’s a reason heat is called the silent killer. Often people don’t know they have a problem with heat until it’s too late.”
In previous heat waves, like the one that hit the Pacific Northwest in 2021, heat-related deaths did not begin to accumulate until the second day, Ebi said.
“At some point, the heat built up internally becomes too much, and your cells and organs start to heat up,” Ebi said.
The United States last year had its highest number of heat-related deaths in more than 80 years, according to an Associated Press analysis of data from the U.S. Centers for Disease Control and Prevention. Death certificates for more than 2,300 people mentioned excessive heat. Heat killed 874 people in Arizona, 450 in Texas, 226 in Nevada, 84 in Florida and 83 in Louisiana.
India has seen prolonged heatwaves this year that have killed at least 100 people. But health experts say the true number of heat-related deaths in India, and possibly other countries, is likely higher.
The “big driver” of this heat is greenhouse gas emissions from burning coal, oil and natural gas, Buontempo said. Those gases trap heat in the atmosphere and change the energy balance of heat coming from the Sun and heat escaping from Earth, so that the planet retains more thermal energy than ever before, he said.
Other factors include warming of the Pacific Ocean caused by El Niño, a spike in solar activity, an underwater volcanic eruption and fewer heat-reflecting particles in the air due to regulations on marine fuel pollution, experts say.
The past 13 months have all set heat records. The world’s oceans have been breaking temperature records for 15 consecutive months, and that warm water, coupled with an unusually warm Antarctica, is helping push temperatures to record highs, Buontempo said.
“I wouldn’t be surprised to see Thursday, Friday and Saturday also set new records for hottest day,” said climate scientist Andrew Weaver at the University of Victoria in Canada, a region that has been battered by the heat.