Among other foci, recent research on adaptation to climatic variability and change has sought to evaluate the merit of adaptation generally, as well as the suitability of particular adaptations. Additionally, there is a need to better understand the likely uptake of adaptations. For example, diversification is one adaptation that has been identified as a potential farm-level response to climatic variability and change, but its adoption by farmers for this reason is not well understood. This paper serves two purposes. The first is to document the adoption of crop diversification in Canadian prairie agriculture for the period 1994-2002, reflect upon its strengths and limitations for managing a variety of risks, including climatic ones, and gauge its likely adoption by producers in response to anticipated climate change. The second purpose is to draw on this case to refine our current understanding of climate change adaptation more generally. Based upon data from over 15 000 operations, it was determined that individual farms have become more specialized in their cropping patterns since 1994, and this trend is unlikely to change in the immediate future, notwithstanding anticipated climate change and the known risk-reducing benefits of crop diversification. More broadly, the analysis suggests that 'suitable' and even 'possible' climate change adaptations need to be more rigorously assessed in order to understand their wider strengths and limitations.