In 2009, at the end of the decade for which no better name than the “noughties” was devised, a flurry of books appeared that attempted to make sense of the preceding 10 years. Most were overwhelmingly upbeat. Some bore signs that their final, more sober chapters had been late additions; tagged on at the end so as to acknowledge the elephant in the room – that the decade had ended in the most severe economic contraction since 1929.

In a little over a week, a second nameless decade will come to an end and the 2020s will begin. The list of upcoming books about the past 10 years appears to be short. Journalists and cultural historians, the sort of people who tend to write such titles, are, it seems, as bewildered as everyone else; concussed by the political and cultural blast waves that detonated throughout the decade. Few are confident enough to think that, in their final moments, the 2010s can be neatly summed up in book form.

Ninety years ago in the US, Frederick Lewis Allen, the editor-in-chief of Harper’s Magazine, coined a term for histories of the recent past written in the immediate aftermath. He called the genre “retrospective journalism” and was himself the author of one of its classics. Only Yesterday, Allen’s history of the 1920s, was published in 1931, having been written during the early stages of the Great Depression. It took its readers on a tour of a nation that no longer existed, the raucous, booming America of the “roaring 20s”.

In 2010, people were still debating if Barack Obama’s presidency meant America was becoming a 'post-racial society'

The one million Americans who bought Allen’s extraordinarily successful book were able to time-travel back to those yearned-for days of wealth and hedonism, and in part the book was little more than nostalgic comfort food, eagerly consumed by people struggling through the depression years. But Allen also reflected on the inequality and the violence of a decade that ended with an even more emphatic economic shock than that of the 2000s.

Today, Only Yesterday is a largely forgotten book but it could well stand as a template for the type of books we are going to need to help us make sense of the 2010s.

Allen began the book by asking his readers to imagine that “time were suddenly to turn back”, and they were to find themselves in the first years of the 1920s. In such circumstances, “what would seem strange” he asked?

It’s a question worth asking again, in the dying days of 2019, from which the first years of the 2010s seem as distant and as alien as the early 20s appeared to the readers of Only Yesterday.

The inherent lament within Allen’s title also feels apt in the last days of 2019 as it must have done in the early 1930s. After all, it was only yesterday that the great indictment against British politics was that it was dull and uninspiring. What concerned politicians and thinktanks back then was how disengaged from politics the public were becoming.

Only yesterday Donald Trump was a reality TV star, Boris Johnson was the Tory’s in-house joker, and Facebook was just a way of tracking down old friends, rather than an existential threat to western liberal democracy.

Facebook Twitter Pinterest Boris Johnson, London’s mayor, stuck on a zipwire in 2012. Photograph: Barcroft Media

Only yesterday the prospect of Scottish independence seemed unlikely and that of a united Ireland utterly implausible.

Only yesterday the Conservative and Unionist party regarded the maintenance of the union as a sacred duty, rather than something that might be surrendered in a political transaction to deliver another objective. Only yesterday we would have dismissed the idea that any single issue, particularly one that was merely the obsession of a tiny minority, could tear British society apart, rupture party loyalties and even damage familial bonds – how many of us are about to sit down to a fourth (and hopefully final) Christmas dinner eaten under a strictly enforced, seasonal ceasefire, a ban on any discussion of Brexit, to prevent inter-generational conflict from breaking out over the sprouts and turkey?

Looking back just 10 years to 2010, it is difficult to understand how we got from there to here but it is easy to see why we are punch-drunk. Since the start of the 2010s we have had four elections, (2010, 2015, 2017, 2019), four prime ministers, seven governments and three referendums (Alternative Vote in 2011, Scottish Independence in 2014 and Brexit in 2016). There have been five Conservative administrations just since the end of the coalition.

Back in 2010, people were still debating if Barack Obama’s presidency meant America was on the road to becoming a “post-racial society”. Now, at the decade’s close, we have become virtually anaesthetised to the fact that the current occupant of the White House feels able to describe white supremacists as “very fine people”.

Facebook Twitter Pinterest US president Barack Obama prepares to deliver his State of the Union address in 2010. Photograph: Tim Sloan/Associated Press

In 2011, we were swept along by the optimism of the Arab spring. In 2019, we watched from the sidelines as President Bashar al-Assad and his backers set about crushing what little is left of the Syrian revolution. The first years of the 2010s seem like a foreign country, a calmer, safer, more stable place where they do things differently.

Partitioning music, fashion and youth culture into decades just about works. Everyone knows what you mean if you talk about 60s music or 80s fashion.

Politics and economics, however, refuse to arrange themselves neatly into decades for our convenience, and at times our determination to divide history up into 10-year blocks distorts our view.

It is tempting, given the results of this month’s election, to see the Conservative victory as an emphatic full stop, one that in the UK definitively marks the end of the 2010s.

Future events will almost certainly complicate that picture. And it is easy to subconsciously catalogue the crash of 2008, and recession it sparked, as the last big event of the 2000s rather than the fundamental economic and political fact of the 2010s.

Recessions and depressions, unlike financial crashes, are not events but processes. They take years to resolve, so just as the reverberations of the Wall Street crash were playing out in the lives of the people who read Only Yesterday, the consequences of 2008 and governmental responses to it were the great seismic forces rumbling under the surface of the 2010s.

Perhaps the ultimate inequality in a decade defined by growing divergence in incomes and experience was how the effects of the crash and the great recession were so unequally distributed.

For millions of people who lived through the 2010s, there was effectively no recovery from the crash. Their incomes never returned to pre-2008 levels.

The austerity policies of the Conservative-Liberal Democrat coalition, which came to power just five months after the start of the decade, made things worse. As did the increasing casualisation of the labour market.

The zero-hours uberisation of employment seemed, in some parts of the country, to turn most jobs into McJobs, not just low paid but insecure in ways that a Victorian dockworker could relate to.

Facebook Twitter Pinterest One of London’s thousands of homeless people beds down in a doorway on election night 2019. Photograph: Christopher Furlong/Getty Images

Meanwhile, homelessness, which was far less common in 2010, increased by 80%, more according to some calculations, in the years since the coalition came to power. Tents and sleeping bags on the streets and in shop doorways became one of the emblems of the decade.

In parts of the UK, the combination of recession, austerity and long-term under-investment resulted in these places being seen as “left behind”, one of the new terms of the late 2010s.

Little surprise then that so many people were in the market for a new type of politics.

Only yesterday, populism was a term mainly encountered by history students doing courses on the 20th century. Ten years on and Trump has tested most of America’s “checks and balances” to near destruction. And he is just one figure among a global axis of nationalist leaders who emerged in the 2010s. In 2014, Recep Tayyip Erdoğan became president of Turkey, the same year Narendra Modi and his Hindu nationalist Bharatiya Janata party came to power in India. The 2010s ended with Jair Bolsonaro joining the club as president of Brazil.

European politics seems similarly transformed. In 2010, Alternative für Deutschland (AfD) didn’t exist. In the federal elections of 2017, the far-right party won 12.6% of the vote and 94 seats in the Bundestag.

Here, the decade began with Ukip obtaining just 3.1% of the vote in the 2010 election. It ends with an election in which the Brexit party tail was able to wag the dog of Conservative party policy.

The politics of extremes tapped into deepening insecurity, and was enabled by disarray on the left, but it metastasised through technologies whose full potential we had not fully appreciated in 2010.

Despite mounting evidence to the contrary, we were still being told in 2010 that the web and social media had brought us to the threshold of a new and almost utopian society.

The technology used by demonstrators worked just as well when placed in the hands of autocrats and state security forces

The analogue autocrats of the world would be toppled in “Twitter Revolutions” led by demonstrators who coordinated their marches and their protests using Facebook and Twitter.

In 2011, this sort of delusional optimism inflected much of the reporting of the Arab spring. For a few months, North Africa and the Middle East were viewed by cyber-utopianists as vast field laboratories in which the democratising and revolutionary potential of social media was to be empirically demonstrated.

The facts on the ground, however, always suggested otherwise. Any delusions that the web represents an irresistible force for democratisation, any suggestion that the new technology was by its very nature on the side of liberal democracy withered to dust over these past 10 years.

Not only was the role of Twitter and Facebook in the Arab spring enormously exaggerated, it was demonstrated, later in the 2010s, that the new technology used by demonstrators worked just as well when placed in the hands of autocrats and state security forces.

The hit movie of 2010 was Aaron Sorkin and David Fincher’s Oscar-winning biopic The Social Network, which dramatised the troubled relationships between the founders of Facebook. What in 2010 seemed like a strangely dark take on a then celebrated phenomenon feels in 2019 like a prescient foreshadowing of a decade that was to come – a decade that ended with Cambridge Analytica, Putin’s troll armies and Mark Zuckerberg called to appear before a congressional committee to defend his company.

Facebook Twitter Pinterest Facebook co-founder Mark Zuckerberg about to testify before a Senate committee in 2018 after the Cambridge Analytica revelations. Photograph: Alex Wong/Getty Images

To round the 2010s off perfectly, Sorkin earlier this year wrote an open letter to Zuckerberg in which he condemned Facebook’s refusal to fact-check political advertisements, a policy that Sorkin said led to “crazy lies pumped into the water supply that corrupt the most important decisions we make together”.

We enter the 2020s free from any delusions about social media as the ally of democracy. Instead, we are asking a question that would have been unimaginable in 2010 – is social media, in its current form, actually inimical to the workings of liberal democracy?

When the 2010s are too distant for retrospective journalism and are handed over to the historians, there is one key statistic that could determine their analysis.

The decade might well come to be seen as one of history’s pivotal periods, not because it was the most divisive or unstable – the 20th century alone has several decades that would be stronger contenders for those titles.

Instead, the past 10 years might be most definitively marked as the decade in which the climate crisis reached a point of extreme urgency.

The year ends with swaths of the Australian bush in flames and the Amazon blackened from earlier conflagrations. Everywhere are signs of ecological collapse, habitat loss, adaptive behaviours and mass extinction.

Only yesterday we had an opportunity – perhaps our last – to change course. In the flurry of events and in the face of constant distraction, we let our attention be drawn elsewhere.

That failure is one that future generations will struggle to understand, or forgive.

OBSERVER WRITERS CHOOSE 10 THINGS THAT DEFINED THE DECADE

TRANSPORT

Electric bikes

A decade ago, electric vehicles were poised to whisk us silently and smoothly around our cities, replacing dirty motors with a new generation of technologically sophisticated smart cars. In fact, the bottom fell out of the car market altogether. Sales dropped to pre-2008 levels as millennials turned their backs on cars, be they electric or petrol-powered. Instead, the electric bike came to represent a shift to healthier, more sustainable, low-tech, low-impact transport. Ebikes became a non-car solution to our car problems. The pundits were right: it’s an electric vehicle, just with two wheels instead of four. Martin Love

TV

Game of Thrones

HBO’s adaptation of George RR Martin’s bestselling fantasy series bestrode the global television landscape from 2011 to its end earlier this year. Along the way, it became the most illegally downloaded TV show of all time, a drama adored by presidents and rappers alike, which, in its first seasons at least, provided some of the biggest shocks ever seen on the small screen. It ended with more of a whimper than a bang thanks to a divisive final season. Sarah Hughes

SCIENCE

Graphene

At the beginning of the decade, the 2010 Nobel physics prize was awarded to Andre Geim and Konstantin Novoselov ‘for ground-breaking experiments regarding the two-dimensional material graphene’. Suddenly, everyone was talking about a material made of a single lattice layer of carbon atoms that had remarkable abilities to transmit heat and electricity while also being extremely strong. Suggested applications include improved camera sensors, DNA sequencing, gas sensing, material strengthening, and water desalination. To date, none of these ideas has been turned into devices but it took two centuries of work with silicon before engineers got the full potential out of that material. Robin McKie

SPORT

The fitness tracker

This was the decade when we became obsessed with taking 10,000 steps a day. According to science, the health benefits are moot but that didn’t stop Silicon Valley firms like Fitbit and Garmin coaxing us into wearing fitness trackers packed with accelerometers and sensors. These data-harvesting devices track our locations, our heart rates, our sleeping patterns and our exercise habits. Who gets the most use from this torrent of data – individuals or the ‘data industrial complex’- is debatable. Ian Tucker

FOOD

The serving slate

It was the object that came to represent the culture wars in the restaurant world throughout the decade; that drew the line between content and style. It didn’t matter that many chefs just thought it made a nice change from the plate. The roof slate as food serving item became a hate object. In 2010, during a review of a Sheffield restaurant, I merely referred to it as a “serving slate” as if that were a thing. By 2015, when the hugely successful Twitter account We Want Plates was launched specifically to mock dismal non-plate serving items, the slate had come to represent all that was wrong with over-wrought food presentation. It’s still out there. I was served a dessert on one only a few weeks ago. But now the digital eye-roll is guaranteed. Jay Rayner

BOOKS

Normal People, Sally Rooney

After Lena Dunham sent up the concept in Girls, you’d think we’d be wary of calling anyone ‘the voice of a generation’ – yet it happened with Sally Rooney. The Irish writer’s debut, Conversations with Friends, was published when she was 26, but it was the phenomenally successful Normal People in 2018, following the intense, shifting relationship of students Connell and Marianne, that confirmed her brilliance at capturing the experience of being young in the 2010s. Holly Williams

TECH

The Amazon Echo

Sadly, it has to be the Amazon Echo ‘smart’ speaker. Sadly because it represented the moment when a tech giant finally broke through the last barrier protecting our privacy – our homes. Alexa exploited our fatal addiction to convenience. And the sales it produces for Amazon far outweigh its loss-making initial cost. John Naughton

CONSUMER

Reusable coffee cups

Ten years ago, coffee shop chains were springing up on high streets across the UK, but with the ‘grab it and go’ revolution came an explosion in the number of disposable coffee cups used – and just as quickly thrown away. It took campaigner Hugh Fearnley-Whittingstall to reveal in his War on Waste programme that some 2.5bn of them end up in landfill in the UK every year. Enter the refillable, reusable portable coffee cup which all retailers now sell and which every smart, eco-conscious consumer should carry in their bag. Designs are improving, and often get you a discount to boot. Rebecca Smithers

ART

The Visitors, Ragnar Kjartansson

Ragnar Kjartansson’s legendary nine-screen installation of 2012 toured the world to universal acclaim, raising the entire level of film art. Shot in one take, in a crumbling US mansion, each screen shows a lone musician in a separate room – drummer in the kitchen, pianist in the salon, Kjartansson on guitar in the bath. Although they cannot see each other, all unwittingly contribute to an astonishingly beautiful lament for the Icelandic artist’s failed marriage. A visual and harmonic feat that mesmerised audiences with its Shakespearian beauty. Laura Cumming

ARCHITECTURE

Cross-laminated timber

Let’s look on the bright side: not on the investment of surplus value in hermetically sealed towers and iconic gee-gaws but in the rise of a technology that might just reduce the impact of construction on the atmosphere. This is cross-laminated timber, in essence a sort of super-plywood, which makes buildings out of the renewable resources that are trees. It wasn’t invented in the last decade, but the 2010s saw its application for the first time to buildings both large and high. The future has ways of making faith in such products look foolish, but here’s hoping that it becomes as commonplace as reinforced concrete is now. Rowan Moore