Often, waterfalls form as streams flow from soft rock to hard rock. This happens both laterally (as a stream flows across the earth) and vertically (as the stream drops in a waterfall). In both cases, the soft rock erodes, leaving a hard ledge over which the stream falls
1. Cash Crop
2. Delta
3. Desertification
4. Drought
5. Shifting Agriculture
6. Farming
The ice caps are melting due to global warming which is being affected by the polluted air
