This chapter reviews the vulnerability to climate change of the key agricultural sector in South Asian countries. After looking at India as an example of how to assess the specific impact of climate change on agriculture, the chapter summarises the ways climate change affects basic plant processes. It then looks at the range of methods used to analyse climate change impacts and their relative strengths and weaknesses, including mechanistic models derived from historic data, the use of field trials, the role of remote sensing data and controlled environment experiments. The chapter also reviews the combined use of different models (e.g. crop, pest, soil and hydrological models) in impact assessments. It reviews the range of current projections for climate change impacts for a wide range of crops across a number of South Asian countries.