It was a day like any other at school, until the teacher told us we were going to watch a video. Then she said something I will never forget.
"There's no need for anybody to get upset or frightened about this," she told the classroom full of children as she wheeled out the TV and VCR.
I may have leaned forward in my seat at that point. Teachers didn't usually say things like that. What was on this video?
We watched it. It was an educational program – probably something made specifically for school children, I'm guessing – about climate change.
It all looked pretty serious.
After the video ended, the teacher again sought to reassure us, saying there was nothing at all for us to worry about, even if everything the video had said was true.
I was only a kid, and the reassurances worked. I was left with the distinct impression that these problems would be solved.
Grown-ups would take care of this, I reasoned. It was the kind of thing grown-ups take care of, given it was serious enough for them to have made a whole TV show about, and then show it to us.
The main thing I remember thinking was that we would probably have to stop driving cars. Cars definitely seemed to be bad.
We probably wouldn't drive cars like that in the future, I thought, with all the exhaust and fumes and everything. Factories and other large industrial buildings also seemed problematic.
That was about 30 years ago, give or take, the day that I found out about climate change. What has changed since that day? Everything. Nothing.
The cars are still here.
Amazingly – even though whole decades have passed since children were learning in school about the causes of anthropogenic global warming – cars with combustion engines that run on fossil fuels can be found on any street.
They were everywhere then. They are everywhere now. We own two, my wife and I. One of them is a second-hand diesel SUV. It is definitely bad.
The other car is another second-hand model, a VW. (It can be hard to tell how bad they are.)
But, then again, lots of things seem bad in this brave new world – a place, 30 years later, which feels neither brave, nor new.
It's not just that the cars are still here. Everything is still here. Everything my generation was repeatedly told would have to change seems to have stayed about the same, more or less.
People still catch planes everywhere, for instance. Last year, we took our little girls, then aged about four and one, to Hawaii for a holiday. It was a great trip.
We got cheap flights, even though I know in my heart there is no such thing as a cheap flight. Aviation is terrible for the environment.
In light of that terrible impact, child-me would not really understand why grown-up-me and all the other grown-ups continue to fly so cavalierly through the sky.
No amount of jet-setting is really sustainable or reasonable or fair to future human societies, or to the peoples of today on low-lying islands, which are being washed away by the first rising tides of climate change.
The truth is, child-me would not understand much of anything about the world today and the indulgent behaviours we have not amended, given the way things sadly are.
All of that would seem pretty bad, child-me would have thought. Surely grown-ups should be taking care of this stuff? And he would be completely right. All of it is entirely problematic, entirely harmful, entirely unsustainable. Kids are very perceptive.
But the biggest, most immediate sustainability problem we are facing today is still the one the video introduced to me all those 30 long years ago: the greenhouse gases. Like so many other things, they never went away either.
As a species we now consume more energy than ever before, with higher emissions from coal-fired power plants helping to push the concentration of heat-trapping carbon dioxide in the atmosphere past all previous levels in human history.
Temperatures are responding in kind, as are melting ice masses all across the globe – threatening rises in sea level that stand to drastically reshape the surface contours of the planet.
There are positives. We have been making admirable gains in the uptake of clean energy.
But those significant breakthroughs have not been enough to mitigate the damage being done by our reluctance to forfeit fossil fuels, and the multitude of conveniences they bring to our daily lives.
For every new solar plant or wind farm, it seems there's a new mining lease, or a newly commissioned coal-fired power station. Massive subsidies are often attached to these archaic, illogical infrastructure projects – you, the taxpayer, fund them.
Child-me would want to ask: why do we maintain this course of inaction, this trajectory into ever more severe forms of environmental devastation, knowing all that we now know and have known for decades?
There is perhaps no satisfying or complete response to answer that question. Only that, despite the best efforts of scientists and environmentalists to capture our collective attention, we have let ourselves be distracted, the truth denied, action delayed.
How could we let this happen? Well, we've let a lot of things happen.
In any case, the world is in a weird, restless place right now, stuck somewhere in the middle between a climate crisis and a crisis of inaction.
Accordingly, it feels like we're moving in slow motion, or maybe not at all, caught in the midst of perhaps the greatest, gravest bystander effect humanity has ever known.
This can go on no longer.
Today, thousands of people around the world – hopefully millions – are striking to say enough is enough. This must stop. We demand action on climate change, we demand you pay attention to us.
Child-me was wrong. Grown-ups never took care of this, never solved the problems. Governments today are still nowhere near doing enough to address the issues, which are both better understood and more pressing than ever.
Clearly, any semblance of adequate or responsible leadership on climate has not come from above. So it must come from within.
The strike today is an inspiration, one borne of the courage and conviction of school students, youth movements, individuals like Greta Thunberg, collectives like Extinction Rebellion, and all the researchers and activists who led their way.
This is their hour, we need to listen to what they have to say. Unlike lots of the grown-ups, they've actually been paying close attention to the science. They know where we are headed, and they know we need to change our ways.
I understand now why, long ago, a kind school teacher didn't want to worry and panic a classroom full of children who watched a troubling video.
Now, I'm a father of two wonderful young girls who aren't yet of school age, and nothing saddens me more than the fearful knowledge of the world I am giving them.
In truth, I have never felt such unique sadness as when I think about their futures on a planet exposed to climate change. But we can't give in to despair.
To mildly contradict my teacher, in light of the information we have, it's okay if you feel upset. And it's perfectly reasonable to be frightened.
But most importantly of all, we need to be doing everything in our power to fight this, and we need to be doing it now.
This article is part of ScienceAlert's special climate edition, published in support of the global #ClimateStrike on 20 September 2019.