it can be just as devastating for countries like rwanda, ere rainfl is plentul. this tiny country is grappling with the problem of a owing population trying to eke out a living on a finite amount of land. as in china and ethiopia, over-farming on the hillsides caused serious erosion and a decline in fertility, forcing poor farmers to move into protected areas, such as the rugezi wetlands, a wildlife site of intertional importance. when farmers drained this marsh to try to grow more food, they not only damaged an important wetland ecosystem, they also had a significant impact three hours drive away in kigali, the capital city. the water that pours from the marshlands is a vital source of hydro power for rwanda's capital. as the wetlands began to dry out, power stations below couldn't generate enough electricity. the rwandan government rented diesel-powered generators to make up the shortfall. doctor rose mukankomeje took me to see them. >> so what is happening here is that those generators... we are renting them from this company, and we are being obliged to rent