Climate change is a fact. It may have stronger impacts in the tropics than in moderate climates. At least from a farmer's perspective declining annual precipitation and higher rainfall variability is a challenge for viable farming strategies in semi-arid regions such as most of Southern Africa. In Central Namibia cattle and game farmers face rangeland degradation. Above all, bush encroachment leads already to a severe loss of pastures' production potentials. A question is will this be accelerated. A local farming system with respect to both, the economic decision making and the responding ecological dynamics to natural pasture dynamics, was investigated with the use of an ecological-economic model. Hereby, innova tive technologies like new bush control measures were considered. To predict agro-ecological responses and future farm developments, 3 different rainfall scenarios have been simulated. Within the simulations the rainfall is stochastically ge nerated and appears as input factor. Main results of climate change are more extreme rainfall events. Therefore, our generated rainfall scenarios are based on a reduced mean precipitation (10%, 20% and 30%) and at the same time increased standard deviations (again 10%, 20% and 30%).