This paper looks at five focal terms in education - curriculum, environment, climate, quality and change - and the interrelationships and dynamics between and among them. It emphasizes the power and utility of the concept of climate as an operationalization or manifestation of the curriculum and the other three concepts. Ideas pertaining to the theory of climate and its measurement can provide a greater understanding of the medical curriculum. The learning environment is an important determinant of behaviour. Environment is perceived by students and it is perceptions of environment that are related to behaviour. The environment, as perceived, may be designated as climate. It is argued that the climate is the soul and spirit of the medical school environment and curriculum. Students' experiences of the climate of their medical education environment are related to their achievements, satisfaction and success. Measures of educational climate are reviewed and climate measures for medical education are discussed. These should take account of current trends in medical education and curricula. Measures of the climate may subdivide it into different components giving, for example, a separate assessment of so-called Faculty Press, Student Press, Administration Press and Physical or Material Environmental Press. Climate measures can be used in different modes with the same stakeholders. For example, students may be asked to report, first, their perceptions of the actual environment they have experienced and, second, to report on their ideal or preferred environment. The same climate index can be used with different stakeholders giving, for example, staff and student comparisons. In addition to the educational climate of the environment that students inhabit, it is important to consider the organizational climate of the work environment that staff inhabit. This organizational climate is very significant, not only for staff, but for their students, too. The medical school is a learning organization evolving and changing in the illuminative evaluation it makes of its environment and its curriculum through the action research studies of its climate. Considerations of climate in the medical school, along the lines of continuous quality improvement and innovation, are likely to further the medical school as a learning organization with the attendant benefits. Unless medical schools become such learning organizations, their quality of health and their longevity may be threatened.