The earth isn't split up into separate "ecosystems" split by continent and land mass you realise? It's one big system that isn't even sealed off from outer space. And in terms of a truly barren planet, the Sahara is teeming with life
The earth is a system of many systems, individual systems within it can collapse and desertification is one of the ways it happens. Runaway collapse of smaller systems can lead to primary system collapse.
The Sahara is teeming with life compared to Mars, but we also know it once hosted significantly more life before it was a desert. That old system collapsed.
The earth isn't split up into separate "ecosystems" split by continent and land mass you realise? It's one big system that isn't even sealed off from outer space. And in terms of a truly barren planet, the Sahara is teeming with life
The earth is a system of many systems, individual systems within it can collapse and desertification is one of the ways it happens. Runaway collapse of smaller systems can lead to primary system collapse.
The Sahara is teeming with life compared to Mars, but we also know it once hosted significantly more life before it was a desert. That old system collapsed.