Adaptation to and mitigation of climate change in Australian agriculture has included research at the plant, animal, and soil level; the farming system level; and the community and landscape level. This paper focuses on the farming systems level at which many of the impacts of a changing climate will be felt. This is also the level where much of the activity relating to adaptation and mitigation can usefully be analysed and at which existing adaptive capacity provides a critical platform for further efforts. In this paper, we use a framework of nested hierarchies introduced by J. Passioura four decades ago to highlight the need for research, development and extension (RDE) on climate change at the farming systems level to build on more fundamental soil, plant, and animal sciences and to link into higher themes of rural sociology and landscape science. The many questions asked by those managing farming systems can be categorised under four broad headings: (1) climate projections at a local scale, (2) impacts of climate projections on existing farming systems, (3) adaptation options, and (4) risks and opportunities from policies to reduce emissions. These questions are used as a framework to identify emerging issues for RDE in Australian farming systems, including the complex balance in on-farm strategies between adapting to climate change and reducing greenhouse gas concentrations.

Climate is recognised as one of the defining features of different farming systems in Australia. It follows that if the climate changes, farming systems will have to shift, adapt, or be transformed into a different land use. Given that Australian farming systems have been adaptive in the past, we address the question of the extent to which research on adaptation to climate change in farming systems is different or additional to research on farming systems in a variable climate.