A basic integrated assessment model is presented in order to assess the likely impacts of greenhouse gases on developing country agriculture. The model begins with a path of greenhouse gas emissions and predicts future concentrations, global warming, a pattern of climate change, climate sensitivity, and future agricultural impacts. All of the above predictions are uncertain. The model consequently predicts a range of impacts, not a certain outcome. Because climate sensitivity is a key element of the predictions, this paper reviews the agricultural climate sensitivity literature in detail. Three methods have been developed which can measure the climate sensitivity of agriculture: cross-sectional analysis, agronomic-economic models, and Agro-Ecological Zone (AEZ) modelling. Cross-sectional analyses compare actual farm performance across climate zones, agronomic-economic models are simulators which have been developed from agronomic experiments on major crops, and AEZ modelling uses detailed ecophysiological relationships to predict plant performance. Although these techniques have primarily been applied to developed countries, there are a handful of studies on developing countries as well. The results suggest that developing country agricultural systems are vulnerable to climate change because they tend to be less capital and technology intensive and because they tend to be in climate zones which already border on being too hot and will likely get hotter. The agronomy results suggest that warming alone would reduce most crop yields in developing countries. However, these expected reductions in crop yields would be offset to some degree by farmer adaptations and carbon fertilization. Global warming is likely to have only a small effect on aggregate production in developing countries. However, expected gains in production in developed countries will probably result in a relative disadvantage to developing countries. Further, specific regions within countries are likely to be adversely affected by climate change. Poor people living in these adversely impacts areas will be disproportionately affected. The international community should help developing countries study these effects, identify adaptation strategies, and prepare programs for low latitude locations to help the rural poor most vulnerable to climate change.