Let us start just before dawn on top of one of the largest, most beautiful and least visited of all the Mayan temples. From up here the world is covered in mist; except for the top of Temple II poking above the clouds. Like a diminutive tropical island, it is a Maya pyramid surrounded by trees floating on an endless off-white sea.

This is Calakmul, the capital of the Kingdom of the Snake, Kaan, once one of the most powerful of all Maya cities and the implacable rival of the far better known Tikal, sometimes just visible far to the south. Now partially excavated and restored, it is seldom visited, as it is far from anywhere and there are few facilities. We were allowed, not without some intense discussion with the solitary guard, to sling our hammocks between trees at the entrance; and to rise in the dark to climb Temple I by torchlight. A rare treat.

As the sky lightens in the east, the mist lifts and dense rainforest is revealed in all directions, right to the horizon. In the darkness below not a single light twinkles; only gentle undulations disturb the ocean of tree tops reaching to the forested hills in the distance.

Gradually a sky to rival the ceiling of the Sistine Chapel forms overhead. Wispy pink, white, yellow, orange, red, mauve streaks of clouds weave patterns on the eggshell blue canvas: a sight to strike awe into the most cynical heart; one which aeons of men, women and children have gazed at in wonder; a never repeated diversity of pure natural beauty. It lasts for only a short time before an intensity begins to make itself felt in the centre of the display. The light is brighter here and the eye is drawn towards the action, as though to the rising of the curtain at the start of an opera. The sublime spectacle of the Overture begins to fade and the play unfolds.

The huge red orb of the sun inches its way over the rim of the earth and suddenly there is life in the forest as a cacophony of birdsong greets the dawn. First, there are the gentle hoots of motmots and a high pitched shriek or two from brown jays; then other small, invisible birds, robins, solitaires and trogons. Flocks of hysterical small green parrots speed in formation above the canopy, screeching to each other that they are late and must go faster. Pairs of their larger cousins fly more sedately past, their conversation more formal. Below, large numbers of oropendola squabble furiously, like angry washerwomen arguing over who gets the best spot at the well. From deep in the forest other, invisible, unidentified calls lay regular emphatic stress on the fact that this is my place, my tree, my fruit. Join me my brethren, but keep away all rivals. An eagle scours the treetops on lazy wings and gives a shriek of high pitched despair at the state of the world.

When the booming starts, all else is silence for a moment at the shock of it. The resonance is so intense, so insistent, so overwhelming in its sheer loudness that none who hear it for the first time can fail to be astonished and to wonder what on earth it can possibly be. Did the Maya worship the Howler monkey as the voice of their god? It would seem likely as it is a sound like no other in the world, one which can be heard from five kilometres away through the densest forest. It seems to be speaking directly to the listener. “Beware” it says “I am all-powerful and I am threatening you with dreadful things if you dare to challenge me”. This is the stirring cry still sometimes heard at dawn and dusk, and even occasionally during the heat of the day, throughout the remaining tropical forests of the New World. When the Maya world was young, more than 3000 years ago, it must have resonated everywhere and spoken to them of powerful spirits. Then, eventually, the people cut their forests down, as they always do, to feed their burgeoning cities and civilizations, and they must have hunted the Howler monkeys almost to extinction. Perhaps they became as rare then as now. Perhaps, living in a landscape worked for food from horizon to horizon, they forgot those gods.

The first rays of sunlight strike us where we sit on the top of Temple I. A moment later, as the mist drops away, Temple II is revealed in all its glory. The stonework is a soft, creamy white, which contrasts delightfully with the surrounding greenery. In its heyday it would have looked quite different, cleared of all vegetation and largely painted bright red, with huge, grotesque multi-coloured masks on the platforms. Upright stone pillars, life-sized statues, or stelae, would have stood in the courtyards below, as in the great cities of Greece and Rome. They were designed to impress and fill the spectator with awe, some soaring up over seven meters and weighing thirty tons. Although the carving may be exquisite and intricate and some of the faces reveal flashes of ethereal beauty, these were not primarily designed, it seems, for aesthetic reasons, as with the Greeks and Romans; instead they were meant to intimidate by showing the power and mystery of the Maya god kings and their priesthood. The figures emerging from the rock were supermen, magicians, guardians of mysteries beyond the comprehension of ordinary mortals. Eric von Daniken, the Swiss author famous for promoting in his many books the idea that extraterrestrial life has existed on earth for millennia and influenced many cultures, claimed that some stelae represented spacemen operating the controls of their space ships. I remember standing in front of a stela at Copan in 1972, not long after von Daniken’s best seller Chariots of the Gods was published, and seeing exactly what he was getting at. With half closed eyes it was easy to imagine that the obscure and convoluted shapes around the central figure were the dials and instruments of some elaborate machine. Of course, it was all nonsense and von Daniken’s hypotheses have been disproved many times, but this does not diminish the power of the imagery nor the impact it must have had on the Maya population.

Now another, lower, temple shows white among the surrounding greenery. Colours rapidly sharpen and patterns form in a million shades of green wherever we look. The hard grey stone of the limestone rock from which the temples are built softens to a delicate pinky yellow in the early light. The breathtaking steepness of the many steps soaring towards the square top jars the memory into feeling again the thigh-wrenching effort of going up them fast, as I always try to do. Not clever, I know, but I am not good at heights and I like to get climbs over quickly, without looking down. I have always preferred the habits of the hare to those of the tortoise.

This was the moment when the idea came to me of a book about how, as with the Maya, all worlds end, as will ours, and maybe we should do something to postpone the inevitable. They destroyed this, the second largest rainforest in the Americas, only for it to be abandoned for a thousand years and allowed to re-grow. Now it is under threat again and seems to me to be a parable of our times. There are so many things I never knew about this part of the world and still only understand dimly. I have lived and travelled with foresters, biologists, anthropologists and natural scientists of all persuasions trying to understand and interpret their many mysteries. But I am not one of them. I am no scientist. I have also travelled in many of the remotest parts of the world, sharing the lives of indigenous people who have a very different view of the world from those I grew up with. I am a dreamer and a story teller, sometimes called an explorer, which in my book is someone who tries to change the world.

And I am angry. Deep down I despair at what we have done to our planet in my lifetime and what we continue to do at an accelerating pace, as I look on helplessly. Are we mad? Can we not see the wonder of our world and what a crime it is for the only species with the brain and brawn to do so, to destroy it? Maybe there is a lesson here. Maybe the Maya didn’t need to vanish; maybe, if they had known what we now know they could have managed their environment better and survived; maybe we can learn from their mistakes and find a way not to vanish, too. I want to step back and see if, by looking at the kaleidoscope of pieces I can begin to understand the puzzle of the Maya collapse, the Petén forest they destroyed and which recovered; to try to make some sense of it all, and to look into the future. Theirs is a story that covers the whole range of human aspiration, creativity and folly but which leads inexorably to the downfall of the performers. Mankind has gone through these same cycles so many times in so many different parts of the world, only to rise again from the ashes of his own destruction and, poorer but little wiser, try to rebuild the world he has destroyed. We seem unable to learn and yet we go on trying. This may be our last chance and looking back at the mistakes of the past may give us some ideas about avoiding them in the future.