Economy-wide and hydrological-crop models are combined to estimate and compare the economic impacts of current climate variability and future anthropogenic climate change in Zambia. Accounting for uncertainty, simulation results indicate that, on average, current variability reduces gross domestic product by four percent over a ten-year period and pulls over two percent of the population below the poverty line. Socio-economic impacts are much larger during major drought years, thus underscoring the importance of extreme weather events in determining climate damages. Three climate change scenarios are simulated based on projections for 2025. Results indicate that, in the worst case scenario, damages caused by climate change are half the size of those from current variability. We conclude that current climate variability, rather than climate change, will remain the more binding constraint on economic development in Zambia, at least over the next few decades.