If upwelling stopped it would cause the food chain to break thus causing the fisheries to collapse
Physical evidence of climate change at least can be shown as vegetation, Glacial Geology, Animals, Precipitation, sea level change. Since Climate change is the change in weather pattern so any unnatural weather pattern can show a change in climate (if it is repetitive) like snowing in July down in Florida
Solid Earth. Long linear regions of geologic features are explained as plate boundaries. For example: Mid-ocean ridges, high regions on the seafloor where
Since oceanic plates are the same density, neither will subduct causing them to rise and potentially create volcanoes
West Africa is mostly a region of plains. Climates range from arid to tropical and they have important agricultural and mineral resources.