I have a distinct memory of sitting in my house in Hayfield with the rain drumming hard on the windows and a view of the sodden fields on the hills across from the cricket pitch. The prospect of days and days without rain, then, would have been a joyous one. Now, in what should be the season of rain, I have walked for seventy days without feeling a single drop of it.

Climate change, desertification, water stress, extreme weather conditions, 12 years to save the planet. We are bombarded with information and impassioned pleas from experts and campaigners telling us that unless we chance our ways, we will soon have irreversibly damaged our planet, our home. However, our whole economy is based on consumption and tied to the use of fuel, so to make those changes surely means a complete revolution in how we live and almost certainly a revolution towards less rather than more.

One of my aims in undertaking this expedition was to see for myself what is happening. I am travelling slowly over a vast swathe of land and through a number of different environments: mountain, river valley, desert and sea.

I am not a scientist or a specialist but I have eyes and I can share with you what I have seen so far. I feel like I have been walking over human history. Where there is still water, there is abundant life. The government built a dam just above the city of Ouarzazate in the 1970s which has regulated the ebb and flow of the Draa River and husbanded its resources. In the upper reaches this means clean drinking water for the city and a rich river valley filled with date palms and vegetable crops where all the sheep are fat and you can feast your eyes on green.

Further down, the story changes. Here, before you enter the grand dunes, is a whole area that used to be inhabited and is now empty, dried out, almost all moisture and all life gone. Gritty sand is held in place by stubborn tammayt shrubs and tamaris trees. Small flowers grow in pockets of dew. But this area used to be a thriving agricultural community. I don’t know this because I have read it in a book or been told. I know it because as I am walking across the dry dirt، I kick up pieces of pottery or I come across a series of old irrigation channels carving their way across the land of some forgotten garden. It was a semi-permanent community, as when the Draa flooded people would come and set up camp and farm for us long as the water lasted, but it was substantial enough for there to be a large market called the suq of Siddi Najji.

Jean-Pierre, my expedition organiser, joined me to explore the ruins of the old suq. Now, all that remains is a surrounding wall, but you can see that it covered a large area and that it was fortified, presumably to protect the grain and produce gathered there from marauding tribes. As we are looking round and trying to imagine it in its heyday, JP produces a surprise for me, an ancient Jewish coin that he found there which dates back to the time of the great Saharan caravan trade. I feel a wave of avarice when he puts it into my hand and only give it back to him reluctantly.

When the excitement fades though, there is a more sobering thought. The last place we saw where people could live now was three days walk away. We also came across our first “dead” well that morning. There was something devastating about that: opening the well cover to look down and see nothing but sand.

It’s not just about man’s intervention, though, about the building of a dam benefitting one area but starving another. It is also about the way the climate is changing. About a week later, we come out of the dunes to walk across Lake Iriqui. It is going to be a long day for us, 25km, so the camels get an extra feast at breakfast. We leave the hills of golden sand and step out onto the lake. It is so flat and so dry and so wide that you can see the curve of the world on the horizon. It is 25km of absolutely nothing. The surface is a bit like walking on butter cream icing: it is slightly set but with a soft underneath which plays havoc with my hamstrings. In 2014 it rained and the men assure me that the lake was a sea of grass and flowers. But that was five years ago.

Days pass and we continue westward into an area where the complicated war between Algeria, Morocco and the Polisario was fought out. There are the traces of war everywhere: dugouts for the soldiers, an exploded land mine and even a cache of live ammunition. The temperature rises and the earth becomes drier and more parched. We are necessarily obsessed with the need to find water for ourselves every two to three days and also enough food for the camels. Camels are not fussy eaters but as we go further the trees and and shrubs become sparser and sparser till they disappear all together.

« Everything is dead. All the nomads have gone. Everyone and everything has gone, » says Brahim C. For days we walk entirely alone, meeting no-one and nothing. We scrape water out of cisterns that have been filled by the last rain and still have some water left. Further on, we beg it from the very few nomads we find. They have enormous heavy-duty plastic bags full of water which is brought into them by lorries.

The shrubs are on blackened and the trees have disappeared all together. For around 250 kilometres we walk through a wasteland, a nightmare illustration of what happens when the water runs out. « It feels like we are on the moon, » says Brahim C. We are tiny specks of life moving across nothingness.

We cross the Jebel Banni and feel the first hint of sea breezes. We are nearing the end of our journey. Thunder rolls in the distance. «Did you hear that? » I ask, full of excitement. « It’s thunder, it’s going to rain. » «No, Zahra, it’s the guns. The military manoeuvres are there on the hills, » replies Brahim C.

And there you have it. The insanity of our species. Whole swathes of land are dying or dead through lack of water, but instead of trying to work out how to fix it, how to actually do something to save ourselves, we are working out how to kill each other more efficiently. Boom, boom, boom go the guns.

This Expedition was sponsored by Craghoppers whose excellent kit you see me wearing all the way down the Draa, Epic who live and breathe adventure and NTT DATA UK Without them, it wouldn’t have happened and I am really grateful for their support.

The Draa Expedition was organised by Jean-Pierre Datcharry of Desert et Montagne Maroc and you can book with him to do part of the route or something similar.