Last month, as I travelled to see family for a very mild Christmas in the UK, I thought about the bushfires simultaneously raging across Australia. They are just one example from a long series of extreme weather events in 2019, including cyclones in India and Bangladesh that displaced more than three million people, Cyclone Idai, which killed more than 1,000 people in southern Africa, floods that displaced tens of thousands of people in Iran, and entire townships laid to waste by Hurricane Dorian in the Bahamas. The year ended with reports of record rates of Arctic ice melt that, through positive feedback effects, are likely to intensify climate heating and impact the future of humanity.

In the face of global catastrophe, it’s hard not to feel daunted. What can I, an individual, do to address such a crisis? Understanding that my daily actions are partly responsible for climate change, I feel a gnawing sense of sense of individual guilt.

It’s perhaps not surprising that I feel like this. I was a child of the 1980s and a teenager in the 90s: my formative years were during something like the most individualistic age in history. While I learned times tables at primary school, Margaret Thatcher was telling the nation there was no such thing as society. During my teenage years, product advertising and globalisation brought a new age of hyper-consumerism, as we were bombarded with education programmes to build self-esteem and TV shows such as Big Brother, The X Factor and The Apprentice, which all glorified self-aggrandisement in subtly different ways.

Developing human minds are like sponges and ours were submerged in ever more individualistic language. Phrases such as “unique”, “personal”, “self”, “me” and “mine” were used with increasing frequency in lyrics, TV shows and books. This immersion took its toll: analysis of data from almost 80 countries shows how the majority have shown marked increases in individualistic attitudes over recent decades.

Having a strong sense of self can be useful, but excessive individualism has its costs. The more we see ourselves as discrete entities, the more likely we are to feel isolated and lonely and to show “selfish” behaviours. As a consequence, rates of anxiety and depression are rising across the world, while the climate and biodiversity crises deepen ever further.

Facebook Twitter Pinterest Anxiety and depression are rising across the world … the village Dashtiari in Iran’s Sistan-Baluchistan region after flooding. Photograph: Alireza Masoumi/ISNA/AFP via Getty Images

Yet times are changing. In the last decade, we may have seen individualism peak. Scientific discoveries have revealed how the perception of a distinct self is an illusion. Our bodies are made from materials that were once parts of countless other organisms, from ancient plants to dinosaurs. Most of our 37tn cells are directed by a genetic code that is a shared heritage not just of humanity but all of life on Earth. You might think your life experiences define you, but the neural networks in your brain that encode these are changing constantly – you are not even the same person you were when you started reading this article. And the new science of social networks shows how we are linked together so closely that ideas, behaviours and preferences flow between us in a way that makes it unclear where one mind ends and another begins.

And people are finding new value in being part of groups, whether it is through activism (Extinction Rebellion, youth strikes, political party memberships) or leisure activities (book clubs, festivals, park runs). New research shows that when people have a broader sense of group identity (for example viewing themselves as global citizens, rather than embracing nationalism), they tend to be more likely to engage in pro-environmental behaviours, such as reducing their carbon emissions, buying sustainably and volunteering. A new age of collectivism seems to be dawning – and not a moment too soon.

So what can be done to make people truly embrace being part of a group? In answering this question, it is worth bearing in mind that the evolutionary history of our brains means we are susceptible to certain biases. When populations face shocks such as environmental catastrophe or social unrest, they are more likely to strengthen bonds between their “in-group” members, while caring less about those outside of the group. This is a defence mechanism to help groups pull together and overcome hardship. Social research has shown that it operates at the country level, too – countries facing crises are more likely to show prejudice towards outsiders and elect authoritarian leaders. Environmental catastrophes are only expected to worsen under climate change, which means nationalism could grow purely due to this evolutionary bias. Yet, is this a sensible response?

In 2020, we live in a highly globalised world, with cross-border flows of money and people, as well as environmental impacts such as the climate crisis and air pollution. If we bond together within nations but with less regard for the welfare of others beyond those borders, we will end up fouling the global commons, ultimately to our own detriment.

Yet there is hope. New research shows how we can escape individualism. Outdoor community activities increase both our psychological connectedness to others and to the natural world. Escape cities to go for a walk with family or friends, or volunteer in a garden or park near you as often as you can. Meditation is proven to alter neural networks in the brain and reduce self-centredness, and solitary activities such as reading and playing computer games have been shown to increase empathy with others. We can all do something small to be part of something bigger and help solve our global problems. Let’s all get on with it.

• Tom Oliver is professor of ecology at the University of Reading, and author of The Self Delusion, which will be published on 23 January.