When record heat feels strangely normal

Summer 2025 was the UK’s hottest on record, the Met Office announced this week. The news somehow felt both inevitable and surprising. There may have been four separate heatwaves, but for many this summer felt pretty normal.

This is because of “shifting baseline syndrome” and the way humans notice – or fail to notice – temperature change.

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Academics have been warning about shifting baselines for decades: the idea that each generation takes the climate and ecosystems of its youth as the baseline or “normality”.

Back in 2020, Lizzie Jones, then a PhD researcher in conservation psychology at Royal Holloway, said this is why parents and grandparents should talk to children about the natural world of their youth.

“Even my parents”, she writes, “recall clouds of insects while they learned to drive, regular snowfall each winter and now rare bird species filling their back gardens.”

For people struggling to put environmental changes in context, local anecdotes like these can be more useful than news stories. “Older people hold a rich library of knowledge about the past,” says Jones, “and how their corner of the world has changed over the course of their lives.”

As time passes, losses accumulate or temperatures creep up. But because we reset our expectations every generation, the change feels ordinary. This is shifting baseline syndrome, and Jones says it leads us to “underestimate how much the environment has changed”.

She particularly focuses on wildlife changes:

“Whatever you or your generation grew up with is considered normal, but as species continue to go extinct and wild habitats are erased, your children will inherit a degraded environment and accept that as normal, and their children will normalise an even more impoverished natural world.”

Read more:
Why grandparents should talk to children about the natural world of their youth

My own grandparents were born near Newcastle more than a century ago. Back then, red squirrels still dominated that part of the world but grey squirrels introduced from America were fast taking over. Skip forward two generations, and I’m not sure I’ve ever seen a red squirrel in the wild. My baseline is that squirrels are grey.

There’s something similar going on with birds in the UK. I grew up in west London and vividly remember as a teenager my first sighting of a bright green parakeet in Richmond Park. My friend Oscar told me a small colony had established themselves in the city’s suburbs. These days, I see these invasive parakeets (originally from the Himalayan foothills, say scientists) more than any bird aside from pigeons. They’re loud and annoying and keep taking food from native songbirds.

My children will never know a London without parakeets: that’s their baseline.

Altered perceptions

But it’s easy to spot when a chunky colourful parrot has muscled a tiny blue tit out of its usual feeding spot. It’s a lot harder to notice that the hottest summer day might now be 35°C rather than 31°C.

In part, that’s because climate change isn’t just altering the weather – it’s altering our perceptions.

Matthew Patterson is a climate scientist at the University of Reading. Writing in June last year, after supposedly cold and miserable weather still hadn’t moved the month much below the long-term temperature average, he noted that the UK has warmed so fast that: “We have come to normalise extreme heat, while relatively cold or even average conditions feel unusual and thus newsworthy.”

We’re also prone to very human biases here. Our collective memory of the weather in any given summer is hugely influenced by conditions during the daytime on perhaps ten weekends. Few people notice whether it was abnormally hot or cold at 3am on a Tuesday, but that’s part of the average too.

This may explain why the UK’s record hot summer still came as a surprise: we pay attention to outliers and recent events (August was cooler than July this year), not to the relentless upward creep of average temperatures.

Read more:
Average months now feel cold thanks to climate change

Lost summers, wilder futures

History offers a sobering lesson in averages and outliers. During the little ice age between the 14th and 19th centuries, average global temperatures cooled by a few tenths of a degree. But that had a huge impact, especially in Europe: failed harvests, frozen rivers, famines and storms.

For climate historian Dagomar Degroot of Georgetown University in the US, this was a case of small global trends masking bigger local consequences. “The comparatively modest climate changes of the little ice age,” he says, “likely had profound local impacts.”

And if less than half a degree can do all that, what might two degrees of warming do in the near future?

Degroot does note that: “People who lived through the little ice age lacked perhaps the most important resource available today: the ability to learn from the long global history of human responses to climate change.”

Read more:
Small climate changes can have devastating local consequences – it happened in the Little Ice Age

The little ice age teaches us how vulnerable we are to climate shifts, but we can reimagine the natural world rather than simply mourn its loss.

Back in 2018, Jones (the conservation psychologist), together with her colleagues Christopher Sandom and Owen Middleton of the University of Sussex, asked young people to imagine what a thriving natural world would look like:

“What they expressed was a desire to see ecosystems with not just more of the wildlife that’s currently there, but the return of species which have disappeared. There was also an undercurrent of sadness about litter and the present absence of wildlife, and hopes for more sustainable lifestyles in the future.”

This is why the authors say we should not simply accept shifting baseline syndrome, as it would mean “progressive damage to the natural world, even with our best efforts”.

Instead, they write, “By broadening our imagination and what we can expect from the environment, we can raise our ambitions for the natural world we leave to future generations.”

While memory loss hides decline, imagination can help reverse it.

Read more:
Forget environmental doom and gloom – young people draw alternative visions of nature’s future

These stories help explain the paradox of the low-key record-breaking summer. Shifting baselines make us forget the past. Human biases mean we notice cool rainy days more than creeping warmth. And history warns us that even small global changes have huge local effects.

Post-carbon

Lots of responses to our question about air conditioning last week.

Dave Pearson says: “When we were younger my wife and I lived in Chad without air conditioning for 10 years. In the hot season our living room would drop to 40 °C just before dawn, then the sun would rise…” He now has an AC unit in his living room: “We see it as a source of convenient comfort at this point, but potentially life-saving as we get older (and therefore more vulnerable) and heatwaves get hotter”

Marolin Watson says her “brick-built South-facing terrace house” tends to stay fairly cool. “However, with people increasingly being forced to live in flats that often rise a considerable distance into the air and may, depending on their orientation, catch the full sun for most or all of the day, I can see that air conditioners will be a necessity.”

Helen Wood says: “if you want air-conditioning, it should be only operated by battery powered by solar panels and not draw on the national grid”

Anne Heath Mennell grew up in Yorkshire and now lives in Australia. She points out “it is an efficient way to cool down, especially if powered by renewables”, but that people once “dreamed of balmy summers. Be careful what you wish for…”

An obvious question this week: what are some climate or environmental changes you have noticed in your lifetime? Don’t give me data: I want anecdotes.