It is easy to imagine the end of the world in Karachi. The naked sun beats down relentlessly on millions, its unforgiving brightness sucking water from limbs on bodies, from leaves on plants, from the earth and from the breath. A life-giving force, this star of ours, turns in these summer months into a life-taking force. Over 65 are already dead, eaten by this same sun; many more will likely die today and tomorrow.

Their bodies are piling up at the morgues maintained by the Edhi Foundation, wrapped in shrouds, cold at last and forever. For the living, the heat can drive one to madness, to risks and to recklessness. Some use their cars as weapons, others their words.

Driven by this mania, some make it out to the sea and plunge themselves into the water; very few can swim. In the meantime, the heat continues: women huddled over mean stoves in hot hovels, children playing in the sewage to cool off, everyone hanging by a thread. Human life, all life, is fragile; a few tens of centigrade and everything will be burnt to a crisp, nothing left at all.

And yet, despite these burning truths that are felt and confronted every day, by everyone other than the extremely wealthy and the unjustly blessed, the world is not ending — not quite.

According to the scientist and archaeologist Craig Childs, author of the book Apocalyptic Planet: Field Guide to the Future of the Earth, the world will not end once, or even at once; the end will be a process, a collection of ends that culminate in extinguishment of our very frail selves, at least for a time.

It could happen like this: the Earth that is currently at the end of the last Ice Age, a period of glacial retreat, could continue to warm faster. It could continue shaving off the layers of its atmosphere, the ones that allow life to keep going.

The glaciers would melt faster, their inner cores forming killer lakes that flow under the ice and erupt suddenly, unexpectedly wiping out mountain towns ensconced in valleys. The oceans would also rise, and heat-making storms would eat up coastal cities made up of vast areas of reclaimed land.

Cities such as Karachi would sink, big portions submerged in the sea, lost to human civilisation until the time the seas recede again, and our plastic bottles and hoardings and bags of chips become the stuff of legend. Remember, it may not be the one cataclysmic storm; it may be many over decades. The Holocene has lasted almost 12,000 years; it will not end in one.

There are places where one can experience the desolation of a world without life — not just human life but all life. In the Atacama desert in South America, it almost never rains and in portions one can find the earth as dry and lifeless as it was over 200 million years ago.

The Earth was just an ice-covered ball then, hurtling in space around a sun that could not warm it enough. The surface of the Atacama desert is made up of salt and sediment. During the day, the sun beats down without a single bush or tree or anything at all that could provide shade.

At night, temperatures can fall below freezing and the salt turns to slush underfoot. In the morning, the salt expands again, and one can hear it moving under the surface, pings and cracks, sometimes loud. It is a surface that has been compared to the surface of the planet Mars as it looks to us now. No one has been able to find signs of life on Mars.

These thoughts about the history of the Earth cannot take the stifling discomfort of the heat away, but they can situate us as beings experiencing something larger than ourselves every single day.

We still live on a planet whose ‘normal’ has never included human life. Other life existed on Earth for millions of years before we came along, and it will likely exist again, in tiny microbial forms, long after we are gone.

The end of a long epoch, the Holocene, is upon us. No one knows what will happen when the glaciers are gone — and they are indeed going and going fast. The Himalayas that populate the north of Pakistan are home to a quarter of the world’s 200,000 glaciers. Many of these are already melting, and if the rate of ice melt continues, Pakistan is at particular risk.

Humans have never been good at imagining time and history beyond the immediate or the life spans of a few generations. The idea of thousands of years is hard to grasp; even with our large brains, we are after all selfish creatures of inanity and minutiae: what the boss said today, whether the electricity will be there tomorrow, are our usual concerns.

At least one of these can provide respite from the heat and the torture of its discomforts. Imagining the scale of history and the elemental dependence of human beings, of the lava under our feet and the evaporating atmosphere over our dome of sky, cannot do that.

This is why such considerations are important: taking a moment to consider the miniscule nature of human existence, of individual existence, against that of a planet which was not always populated by us or our small concerns, can provide a different kind of relief.

Inclined as humans are to agonise over things that do not matter, constantly counting up our fears and worries, the alteration of perspective — the consideration of a planet not as a stage for our lives but our own lives as only minor parts in an unimaginably long story, sometimes cold, sometimes hot and often utterly desolate — provides perspective.

Dawn/ANN.