OPEN LOOP:
Waste from one part of the process ❌ the loop.
❌ from the loop ❌ be used again.
Considered to be ❌.
The energy in these loops comes from the ❌ originally.

CLOSED LOOP:
Loop can keep going round and round ❌.
Waste from one part of the loop becomes ❌ for the next part.
Considered to be environmentally ❌.
The ❌ in these loops comes from the sun originally.
Most cycles in ❌ are this type.

Why does desertification happen?
- ❌
- over grazing
- intense farming
- ❌ farming techniques (❌ and burn)

Why do these cause desertification?
- leaves and ❌ slow down the rain, so it hits the ground with less ❌; without this, the soil quickly ❌ and is washed away
- vegetation soaks up water from the soil, so reduced ❌ increases the risk of surface ❌
- the roots would hold the soil together, preventing it from being ❌
Solutions to deforestation?
- windbreaks
- controlling ❌
- reforestation/❌