Earth is getting hotter – so why is this summer so dismal?

By Jack Marley for The Conversation

Melbourne: Fossil fuels have kept Earth 1.5°C hotter than its pre-industrial average temperature for more than a year now.

And yet, where I live in the UK, this summer has felt like one of the coolest I can remember. If the planet is in the middle of “a large and continuing shift” to a hotter climate as scientists say it is, why is the weather so cold during what is supposed to be the warmest time of year?

Satisfactory answers to questions like this can nip climate scepticism in the bud. Luckily, the experts we’ll hear from today have plenty.

Matthew Patterson is an atmospheric physicist at the University of Reading. He says that the UK’s dismal summer hasn’t been unusually cold – in fact, measurements of temperature, sunlight and rainfall in June 2024 were all close to their seasonal averages.

Unfortunately, “average” conditions now feel colder than they used to.

Everything cold is new again

Europe has warmed at roughly double the global average rate since the 1970s, while extreme summer temperatures have risen even faster. The UK has had its five hottest days since 1910 in the past five years.

“Such a rapid rate of warming means we have come to normalise extreme heat, while relatively cold or even average conditions feel unusual and thus newsworthy,” Patterson says.

Patterson argues that people are quick to forget how the climate felt even in the recent past. And of course, we have no reference for what it was like before we were born. Ecologists refer to this phenomenon as shifting baseline syndrome: each new generation comes to accept as normal what previous generations would have considered extreme.

A rapidly warming climate will still produce extremely cold weather. It is winter in southern Australia and the weather there has been unusually cold according to Andrew King, a senior lecturer in climate science at the University of Queensland:

“Notably, Tasmania has had its lowest July temperature on record and the second-lowest minimum temperature for any time of year with –13.5°C at Liawenee in central Tasmania early on Thursday morning.”

Despite the cold snap, winters in Australia are still warming. The frosty nights and chilly days of the last couple of weeks have become scarcer and less intense over the past few decades. Australia has set records for heat far more regularly during that time. But when the right weather conditions align, cold records can still be broken locally.

Rather than fixate on these moments, it’s important to keep track of the average.

“While we still see record cold temperatures at individual weather stations, we won’t see another cold record in the global average temperature and probably not even in the Australian average temperature,” King says.

Unremarkable or terrifying

It’s not hard to find weather that seems more typical of a world warming to a dangerous degree. When temperatures topped 50°C in Saudi Arabia in mid-June, more than 1,000 people undertaking the Hajj pilgrimage collapsed and died.

“I calculated walking about 80 miles (129 kilometers) during my pilgrimage,” says Ahmet T. Kuru, director of the Center for Islamic & Arabic Studies at San Diego State University. “This year’s extreme heat added to the challenge.”

Similar temperatures were recently recorded in the southwestern US. One person died and another was hospitalised on Sunday when the mercury hit 53.9°C in Nevada’s Death Valley national park.

Hospitals in Karachi, Pakistan have been overwhelmed by weeks of high heat. Temperatures approaching 38°C killed several people in Greece last month and more than half of prefectures in Japan have issued heatstroke alerts in recent days.

The news that Earth’s average temperature has exceeded 1.5°C of warming for an entire year is alarming even if your area hasn’t seen deadly heat yet. Here are Mathew Barlow and Jeffrey Basara, climate scientists at UMass Lowell:

“In the Paris climate agreement, countries worldwide agreed to work to keep global warming under 1.5°C, however that refers to the temperature change averaged over a 30-year period. A 30-year average is used to limit the influence of natural year-to-year fluctuations.”

“So far, the Earth has only crossed that threshold for a single year. However, it is still extremely concerning, and the world appears to be on track to cross the 30-year average threshold of 1.5°C within ten years.”

This is humanity’s first taste of what scientists would consider truly dangerous global climate change. But you can only feel the weather at a single place in time. As Barlow and Basara explain, that varies a great deal from day to day, week to week, month to month and year to year.

While the global average temperature steadily rises, your partial experience of it – wherever you are in the world – may be unremarkable or terrifying.

Once the world’s weather stations have weighed in, summer 2024 will probably be declared the hottest on record. It is also certain to be among the coldest of the rest of your life.

(Jack Marley is Environment + Energy Editor, UK edition)