Options for adapting agriculture to climate change: Australian and New Zealand examples

Many organisational levels from international institutions to the farmer must be involved in adapting agriculture to anthropogenic climate change. Each level has a different role to play. Governments should consider long-term scenarios and the implications for such things as population and land tenure policy, and policies that influence bank lending arrangements. Individual farmers cannot plan for highly uncertain specific scenarios eventuating decades ahead, given other faster-acting external factors influencing them. They can, however, strive for flexibility and keep good farm climate and management records to allow faster reactive responses. In the highly variable climate of Australia, this approach, combined with informed use of seasonal weather forecasts based on the Southern Oscillation Index, should permit automatic reactive adaptation to anthropogenic climate change as a spin-off from routine proactive and opportunistic responses to natural climatic variability. At the level of agricultural research, there are anticipatory adaptive options that can be investigated and developed, Examples are genetic modification of plant and animal species by breeding, and changes in the management of individual crop and pasture systems. For New Zealand, a strategy is proposed for iteratively relating forage species improvement and evaluation to the implications of scenarios of atmospheric and climatic change. To some extent, the yield of annual temperate crops, such as Australian wheats, may largely self-adapt to earlier springs where development is controlled mostly by the passage of thermal time. Thus breeding would need only to fine tune to the change. There are also modifications that can be made in the management of whole farm systems. However, situations may arise where it is more appropriate to alter land use than to adapt the existing land use. Hence, strategic approaches to the development of policies, institutions and infrastructure are required that can allow regional adaptation of agriculture over longer time-scales.