This is episode 224 — the sound in the background is the weather - the other sound is the creaking of wagons as another great trek begins.

We’re going to trace the arc of Southern Africa’s climate, beginning in the early 19th century, before turning to the decade under review — the 1860s — and following the path of the Griqua Great Trek into Nomansland.

First let’s get our heads around the cycles of drought and flood in southern Africa.

The pernicious climate.

As Professor Mike Meadows of UCT’s Environmental Sciences Department observed back in 2002, South Africa’s climate has long danced to an unpredictable rhythm — one marked by dramatic shifts in both rainfall and its timing. Precipitation follows a kind of cycle, yes, but one that keeps its own secrets. Some years bring bounty, others drought, and the line between the two is often sharp and sudden. The climate, in short, plays favourites with no one — and when it comes to rain, it can be maddeningly capricious.

So while the calendar may promise a rainy season, it rarely tells us how generous the skies will be. The patterns are there — but the quantities? That’s anyone’s guess. South Africa, after all, is a land of dryness. Over 90 percent of its surface falls under what scientists call “affected drylands” — a polite term for places where water is scarce and the margins are thin. The rest? Even drier. Hyper-arid zones, where the land holds its breath and waits. And by the mid-19th century, much of this land was beginning to fray under the strain — overgrazed, overworked, slowly giving way to the long creep of degradation.

South Africa’s landscape is anything but simple. It’s rugged, sculpted by time, with steep slopes and a dramatic stretch from the tropics to the temperate zone. But the story of our climate doesn’t end on land. It’s shaped by a swirling conversation between oceans and continents — a conversation held over centuries by systems with lyrical names: the Mozambique Channel Trough, the Mascarene High, the Southern Annular Mode, and the twin dipoles of the Indian and Atlantic Oceans. Then there’s the heavyweight — the El Niño-Southern Oscillation, or ENSO — which has long held sway over our rainfall and drought cycles.

The dry was one of the motivations for another Great Trek about to take place.

The Griqua’s who’d been living in the transOrangia since the late 1700s began to question their position in the world. With the Boers now controlling the Free State, and Moshoeshoe powerful in Lesotho, it was time to assess their options.

In 1861, the Griqua joined the list of mass migrations of the 19th Century. There had been the effect of the Mfecane, then the Voortrekkers, and now, the Griqua. Two thousand people left Philippolis to establish themselves in Nomansland, far to the east, past Moshoeshoe’s land over the Drakensberg. The reason why historians like Cambridge’s Robert Ross call it spectacular was the road that the Griqua cut for themselves across the high ridges of the mountains, a remarkable feat of engineering for the time.