Wednesday, March 14, 2007

Agricultural and biodiversity adaptations to climate change

I have been thinking about adaptive policies for managing biodiversity in the face of climate change and, at the same time, becoming interested in the same types of adaptive policies for agriculture. Some politicians see possibilities of exploiting new regions to take advantage of the global impact of climate change. I am interested in thinking about synergies and substitutabilities between biodiversity and agricultural adaptation policies.

Given dramatically high levels of climatic uncertainty and of the adaptation capabilities of agricultural and biodiversity systems it is probably unreasonable to suppose that very specific management plans will be provided by considering the underlying economics. The best that probably can be hoped for is an improved broad understanding of how planning might proceed.

In the limit, with high uncertainty, specific policies might be replaced with plausible parables such as seeking to promote overall environmental resilience or pursuing new sustainability objectives. With less uncertainty more specific prescriptions should be possible.

Suppose for example one was planning for joint conservation and agricultural land uses in a region subject to climatic change. Planning to improve the resilience of environmental systems in such a setting might have competitive or complementary roles with agriculture in terms of land use policy. The roles might be competitive to the extent that biodiversity seeks to relocate to a region where agriculture is expanding in the face of climate change. The roles are complementary if, as seems less plausible, land that was used in agriculture becomes less useful for that purpose but is suitable for biodiversity conservation.

Similarly pursuing measures to strengthen the resilience of biodiversity resources in a region might increase the productivity of agriculture in that region – for example measures to improve a salinity problem or to invest in improved water resource endowments. This could a source of ‘no regrets’ policy advantage for agriculture if realized climate changes turned out to be less severe than anticipated and hence unnecessary for conserving biodiversity.

In an obvious sort of sense cultivated plants and animal husbandry are human-supported species that depend on sunshine and rainfall as inputs in the same way that natural populations do. Apart from flagship species rarities which can be shifted by human-generated ‘assisted migrations’ to new habitats however most biodiversity will need to relocate naturally in response to climate change. Cultivated plants and animals however will relocate on the basis of decisions taken by individual farmers and governments.

Generally it makes sense to try to optimize the adaptive response jointly. But it is reasonable to suppose that government will attach a lower priority to biodiversity adaptations.

By the way adaptations to climate change impacts on agriculture are discussed in an attractive recent paper from ABARE. It makes some nice points which I summarize in no particular order:
Existing strategies to manage climate variability provide opportunities for adapting to climate change. The same is true for biodiversity. Existing migratory and relocation moves as well as adaptations to drought and exogenous events such as bushfires are useful in thinking about biodiversity adaptations.

Key agricultural strategies for adapting to climate change include crop diversification, species changes, shifting planting seasons and changing crop management practices such as spacing, tillage, crop rotation, erosion and salinity management, moisture conservation and pest management. For livestock production adaptations include changing livestock breeds, managing pastures, pests and diseases. Many of these ideas are suggestive of corresponding biodiversity policies and many have direct implications for biodiversity.

Improving water use efficiency and water trading improve the flexibility of agriculture to adapt.

There is a debate about the role of public and private sectors in promoting agricultural adaptations. Clearly government can support agricultural research in, for example, developing new crop varieties that will be resilient in different temperature envelopes. Government can also provide information on climate change impacts.

Price and income subsidies and fixed or guaranteed water allocations will reduce the incentives of farmers to make behavioural changes in response to change.
The paper discusses many other things including a case study of the wheat belt area of Western Australia that I am interested in. It has an excellent bibliography on agricultural adaptations.