(The story was less grim than the title led me to expect.)
It's an interesting story! I do wonder if the headline was optimized for clicks to make people think it was the sea going to the herders, rather than the other way around.
Alex Orenstein, a livestock mapping expert, says the transition of herders like Mr. Ahmed to the sea is completely unprecedented. Traditionally, he says, nomadic herders in West Africa have had an effective strategy for adapting to climatic changes: They simply moved to new pastures. But herders in Mauritania are increasingly hemmed in.
No doubt true for nomadic herders specifically, but all over Scotland there were cases of inland subsistence crofters being moved on to marginal coastal land during the Clearances. I did some work here https://en.wikipedia.org/wiki/Badbea where the people cleared off the straths inland settled and tried to become herring fishermen, before moving more or less en masse to New Zealand.
Though the move wouldn't have covered the same distance as the Mauretanians - probably only a few tens of miles.
Or became kelp farmers, and that industry then completely collapsed when the Napoleonic wars ended and you could buy much cheaper soda ash from Spain (since saltwort is like 10 times more efficient).
The museum in Arran this summer had a bunch of really interesting records on display of exactly where everyone moved to in (iirc) Quebec. Arran specifically also has a weird problem that when tenant farmers finally got some rights after the Skye Crofter's War, those rights didn't apply to Arran because it's not counted as "Highlands" in the Crofters act
https://en.wikipedia.org/wiki/Crofters_Holdings_(Scotland)_Act_1886