Hottest June on record adds to 13-month streak of record-breaking temperatures

Hottest June on record adds to 13-month streak of record-breaking temperatures

Last month was the warmest June on record and the 13th straight month of record-breaking temperatures, according to the European climate service Copernicus.

It also marked the 12th month in a row that the world was 1.5C warmer than pre-industrial times.

“It's a stark warning that we are getting closer to this very important limit set by the Paris Agreement,” Copernicus senior climate scientist Nicolas Julien said in an interview. “The global temperature continues to increase. It has at a rapid pace.”

That 1.5C temperature mark is important because it's the warming limit nearly all the countries in the world agreed upon in the 2015 Paris Agreement. Julien and other meteorologists have said the threshold won't be crossed until there's a long-term duration of the extended heat — as much as 20 or 30 years.

“This is more than a statistical oddity and it highlights a continuing shift in our climate,” Copernicus Director Carlo Buontempo said in a statement.

Earth's more than a year-long streak of record-shattering heat could soon come to an end, but not the climate chaos that has come with it, scientists said.

How hot was this June?

Around the globe, the average temperature in June reached 16.66C, which is 0.67C above the 30-year average for the month, according to Copernicus.

It broke the record for hottest June ever, set last year, by 0.14C and is the third-hottest of any month in Copernicus records, which go back to 1940, behind only last July and last August.

It's not that records are being broken monthly, but they are being “shattered by very substantial margins over the past 13 months”, Julien said.

“How bad is this?” asked Texas A&M University climate scientist Andrew Dessler, who wasn't part of the report.

“For the rich and for right now, it's an expensive inconvenience. For the poor it's suffering. In the future the amount of wealth you have to have to merely be inconvenienced will increase until most people are suffering.”

What impact do high temperatures have?

Even without hitting the long-term 1.5C threshold, “we have seen the consequences of climate change, these extreme climate events," Julien said — meaning worsening floods, storms, droughts and heatwaves.

June's heat hit extra hard in southeast Europe, Türkiye, eastern Canada, the western United States and Mexico, Brazil, northern Siberia, the Middle East, northern Africa and western Antarctica, according to Copernicus. Doctors had to treat thousands of heatstroke victims in Pakistan last month as temperatures hit 47C.

June was also the 15th straight month that the world’s oceans, more than two-thirds of Earth’s surface, have broken heat records, according to Copernicus data.

Most of this heat is from long-term warming caused by greenhouse gases emitted by the burning of coal, oil and natural gas, Julien and other meteorologists said.

An overwhelming amount of the heat energy trapped by human-caused climate change goes directly into the ocean and those oceans take longer to warm and cool.

A woman uses a fan as she walks with her companion on a hot day in Beijing, 16 June 2024. June 2024 was the hottest June on record, according to Copernicus.
A woman uses a fan as she walks with her companion on a hot day in Beijing, 16 June 2024. June 2024 was the hottest June on record, according to Copernicus. - AP Photo/Andy Wong, File

What role does El Niño play?

The natural cycle of El Niño and La Niña, which are warming and cooling of the central Pacific that change weather worldwide, also plays a role. El Niños tend to spike global temperature records, and the strong El Niño that formed last year ended in June.

Another factor is that the air over Atlantic shipping channels is cleaner because of marine shipping regulations that reduce traditional air pollution particles, such as sulfur, that cause a bit of cooling, scientists said. That slightly masks the much larger warming effect of greenhouse gases.

That "masking effect got smaller, and it would temporarily increase the rate of warming" already caused by greenhouse gases, said Tianle Yuan, a climate scientist for NASA and the University of Maryland Baltimore Campus who led a study on the effects of shipping regulations.

Will 2024 beat last year's heat record?

Climate scientist Zeke Hausfather of the tech company Stripes and the Berkeley Earth climate-monitoring group said in a post on X that with all six months this year seeing record heat, “there is an approximately 95% chance that 2024 beats 2023 to be the warmest year since global surface temperature records began in the mid-1800s.”

Julien said Copernicus hadn't computed the odds of that yet. Last month, the US National Oceanic and Atmospheric Administration (NOAA) gave it a 50% chance.

While still hot, global daily average temperatures in late June and early July were not as warm as last year.

“It is likely, I would say, that July 2024 will be colder than July 2023 and this streak will end,” Julien said. “It's still not certain. Things can change.”

Andrew Weaver, a climate scientist at the University of Victoria, said the data show Earth is on track for 3C of warming if emissions aren't urgently curtailed. And he feared that an end to the streak of record hot months and the arrival of winter's snows will mean “people will soon forget” about the danger.

“Our world is in crisis,” said University of Wisconsin climate scientist Andrea Dutton. “Perhaps you are feeling that crisis today — those who live in the path of Beryl are experiencing a hurricane that is fuelled by an extremely warm ocean that has given rise to a new era of tropical storms that can intensify rapidly into deadly and costly major hurricanes.

"Even if you are not in crisis today, each temperature record we set means that it is more likely that climate change will bring crisis to your doorstep or to your loved ones.”

Copernicus uses billions of measurements from satellites, ships, aircraft, and weather stations around the world and then reanalyses them with computer simulations. Several other countries' science agencies — including NOAA and NASA — also produce monthly climate calculations, but they take longer, go back further in time, and don't use computer simulations.