In a fast-changing world, it’s a reassuringly unvarying truth that whenever the novelist Jonathan Franzen weighs in on current affairs, it drives people bonkers on social media. And so it went, a few weeks back, when Franzen published a New Yorker essay wondering if we should give up hope of decisively averting the climate apocalypse. Something about the sheer Franzenness of Franzen makes it hard for his critics to focus on what he’s actually saying: he was attacked as a nihilist and a fatalist, even though he urged action and investment to combat global warming; and the New Yorker was chastised for not assigning the piece to a climate scientist, even though the relative impotence of public pronouncements by climate scientists was central to his argument. It was difficult not to interpret the ferocity of the response as evidence that he’d broached a subject many would rather avoid.

Lost in the commotion was what I’d say was Franzen’s most important reminder: that our capacity for concern is finite, and we ignore that finitude at our peril. Each of us has limited time, energy and other resources, and so, inevitably, if your sole priority is achieving victory in a planetary-scale existential battle, there’ll be nothing left for anything else. “Keep doing the right thing for the planet, yes,” Franzen wrote, “but also keep trying to save what you love specifically – a community, an institution, a wild place, a species that’s in trouble – and take heart in your small successes.” They needn’t be explicitly climate-related, either. There’s something wrong with a moral code that says you shouldn’t spend your spare time caring for a dying relative (say) because it’s time you could have spent saving the environment.

You might object, of course, that real-life climate activists don’t neglect their dying grandparents; they manage to attend to both demands. But then you’ve already granted Franzen’s point – that it’s justifiable to withdraw some of your finite energy from what seems like the only global priority in order to reinvest it locally, and on what matters most to you.

More than justifiable, in fact: it may be the only way to avoid paralysis or despair in the face of the world’s problems. In the smartphone age, as David Cain observed recently on his blog raptitude.com, our limited capacity for concern is distributed over so many urgent demands that it’s like “releasing a tiny drop of water on each square inch of a forest fire”. Imagine, he wrote, if you could gather up all the public concern and distribute it differently, so that several thousand people would make one specific issue – or sub-issue, in the case of the climate – their primary moral concern for a decade. It’s hard to imagine more progress wouldn’t be made.

We can’t engineer the world that way, obviously. But we could probably try harder, as individuals, to pick a handful of battles in which to invest our finite concern. The trickiest part would be ignoring all the others. “Not my problem!” we’d have to think, when encountering a story about Syrian refugees, or fires in the Amazon. Not from callousness, but because we’d nominated some different problems as “ours”, and were already busy making a difference.

Listen to this

The veteran ecologist Joanna Macy explores environmental activism as a “dance with despair” on the podcast On Being.

oliver.burkeman@theguardian.com