12 December

You know when you worry about everything all the time? Sometimes it turns out that it’s the thing you haven’t bothered to think about – the thing that’s too outlandish, even for you – that turns out to be the one that’s going to get you. That was what happened that day.

It was a cold afternoon, a Thursday. There was a Christmas party going on at college and everyone else was there. I never went to parties, so I had slipped out of the building and melted away (knowing no one would notice), and now I was walking round the park to kill time. Mum worked at home, and I didn’t want to see the pity and frustration on her face when she realized I hadn’t gone to the Christmas thing. I was planning to wait it out for a bit and then pretend I’d had a lovely time.

The grass was still crunchy underfoot in the shade. I crisscrossed the park to stomp on the crispest leaves, telling myself that I would need to be braver than this in future, because I had promised myself I would audition for the play, and a girl who couldn’t walk into a dining hall to eat a handful of Quality Street and listen to the student choir singing ‘Jingle Bells’ wasn’t going to be very good at standing on a stage and declaiming Shakespeare.

Whenever my stomping took me close to the children’s playground I looked at the toddlers running and climbing and tried to remember if I had ever felt so carefree and un-self-conscious.

I wished afterwards that I could go back and recapture that ordinary boredom and mild self-loathing, but it turned out that nothing feels the same when all your assumptions about what might happen next have been ripped away, and you’ve discovered you don’t have a future at all.

It changed slowly, and then fast. A man was staring at his phone. Then half the adults in the park were doing the same. Someone cried out. The atmosphere changed (appropriately), and I took my phone out of my pocket to see what had happened.

A newsflash had been delivered to my lock screen, even though I had settings that definitely didn’t allow them.

The United Nations, in conjunction with a coalition of the world’s governments, has confirmed that an accelerated atmospheric shift is underway and that it will have ‘profound consequences’ for the Earth and its population. Click for more details.

I clicked, but there were no more details because the network had crashed. I didn’t need to see those details anyway, because I’d seen the rumours over the past few months, and had happily ignored them while worrying instead that I couldn’t speak to the girl I liked, and that I wasn’t sure if I was brave enough to audition for Juliet. That proves that even if you try to keep yourself safe by dwelling on all the bad things you can think of, something huge will always manage to slip through. I knew what the story was: the thawing of the permafrost had unleashed such an unexpectedly massive load of carbon dioxide, laced with various toxins, that it was fast becoming impossible for humans to live here. We didn’t have time to evolve to thrive in our new atmosphere. That at least was what the rumours had said.

Later, when I did get to read the detail, I discovered that it was all true, and a date had been calculated for the definitive change of the air: September the seventeenth. Less than a year away.

Anyone with existing breathing difficulties would probably die before that. So would the birds, and some of the animals. We had done this to ourselves, and to the creatures, and there was very little we could do about it. It was the catastrophic breakdown of everything.

In the park everyone was just staring, like I was. Even the children, who couldn’t possibly have understood, seemed to be frozen, mid-jump, mid-climb, mid-shout.

If the robins in the trees had had phones, they would have been looking at them too (and tweeting: ‘The birds die first?’). The squirrels in the branches (‘And the small animals?’). The dogs on the leads. The cats. The rats. The ants and the mice. The newsflash beamed across the world in a moment, invisible until it landed, and then everywhere.

The world paused. I watched the other people. Everyone had taken something out of a pocket. Everyone was staring. There was a hiatus, because it was not a thing you could understand at first.

Then things continued. A discarded burger wrapper was the first to move. The wind blew, the children jumped, the birds flew, and everyone apart from me started to talk. A man started crying. I watched people trying to make phone calls. The rumours had been around for months and it shouldn’t have been a surprise – and yet it was.

I walked to the nearest bench and sat down. There was a woman already there, who was old enough to have been my grandmother and I wished she was (my grandmother had died last year), and we looked at each other, then quickly away.

‘Well,’ she said. ‘How about that?’

I couldn’t answer.

‘OK for me really. I’ve lived my life and I’ll take all my pills before this happens. This isn’t the way I’m going to go, thank you very much. It’s you young people … I mean, look at them, the kiddies. And you. A pretty girl like you. So much ahead.’

I wished she would stop talking. I followed her gaze to the children in the play park, and thought of Sofie and Hans-Erik. I pulled my hair round my hand and nodded. I wrote a text to my mum that just had a couple of words in it (Oh, Mum) but it didn’t go through. I wanted to see Zoe, and I wondered what the scene was like at the Christmas party. I pictured it: happy, noisy, and then frozen, as everyone realized that there wouldn’t be a next Christmas. I sat still for a while and just stared at the park. The grass was scrappy at this time of year, and I wondered whether the worms were going to be all right.

I didn’t realize I was running, but when I looked down I saw that my feet were slapping over cold grass, and I was heading for the street. I bolted down the pavement, ignoring everyone, swerving on to the road when I needed to. We lived two blocks from the park, and as soon as I was running downhill towards home, the door swung open and there was my mother, on the threshold, waiting. I ran straight into her, and she grabbed me and held me, and even though I was taller and chunkier than she was, I wanted to be her baby again.

When I stopped trembling we sat on the sofa. Mum made us both sweet tea, handing me the mug with a hand that wasn’t quite steady. She had somehow gathered together all the chocolate in the house and laid it out on the coffee table.

‘Right,’ she said, when she’d settled down beside me. She handed me a Twix. I opened it. ‘OK. So it seems I was wrong.’

My parents (all four of them, but particularly Mum) had insisted that the stories were rubbish, and I’d happily believed them. Teachers said it was scaremongering, and that we were being hysterical by believing it. Mr Baxter, my drama teacher, had given us a whole month of lessons themed around doomsday cults and mass hysteria, to give us what he called ‘much-needed perspective’. Everyone had come together to push the view that these rumours were what happened when you allowed anyone to say anything they wanted on the internet anonymously.

My mum – the person I looked to for reassurance above everyone else – had insisted so hard that there was no truth in it that I had been a tiny bit suspicious of what she really thought. She’d called it ‘laughable’ and ‘stupid’. She said science didn’t work like that. She did big laughs out loud to show how ridiculous it was. She agreed that there were lots of things to worry about, but insisted that we weren’t all heading for a mass extinction in the immediate future at least, that if there was something like that on its way, scientists would have sorted it out by now.

She said we should take it as a wake-up call and clean up our act.

Now, of course, she was struggling, but, still, she was trying to be brave. I had chosen to believe her, and Mr Baxter, and everyone else, because it seemed too outlandish even for me to spend too much time worrying about this. It had barely made my top-eleven worries until now. I knew that I would have to scribble over the other ten because this was now the only thing.

I pictured the permafrost. I imagined it thawing out, and a green cloud coming from it and spreading across the planet. There was a reason that that stuff had been locked away, and we had undone it.

I dropped the Twix and grabbed Mum’s hand and gasped for breath. Thinking about it made me panic and fill my lungs with all the air I could, as fast as I could, while it was still there.

She held me and muttered into my hair. ‘Oh, Libby,’ she said, and then she whispered something about violence, but I didn’t stop to ask what she meant. I supposed there would be violence, but I had no capacity to think about that. Not yet.

There was, of course, a caveat, and when Mum found it in the small print she seized upon it. ‘Look!’ she said. ‘It might be all right. They might be able to sort it out.’

I didn’t understand how, but there was a chance that things might be OK. There was an operation underway to minimize the effects, to recapture the carbon and neutralize the other stuff. Meanwhile, finally, we were cleaning up our act, for all the good that would do. All fossil-fuel plants had been closed, all flights had been stopped, and forests were being intensively planted in an attempt to try to push the genie back into the bottle. I didn’t read the science: I just looked at the numbers. Seventy per cent, they think. Seventy per cent we all die. Thirty per cent, somehow, life continues, though it might be through gas masks.

Seventy per cent was a lot. If I got that in a test at college I would be quite pleased.

One minute you’re walking in the park, pretending to be at a party. Then you discover that the next nine months will probably be your last. Everyone’s last: a reverse gestation. You realize that you happen to be alive at the time when your species becomes extinct, and you wonder whether any part of you could come to find that quite interesting.

You have to decide whether to go with it meekly like you usually do, or to do something brave, to live your last months with all the energy and bravery you can muster, to rage against the dying of the light.