Thursday, February 22, 2007

Climate change and agriculture

I am developing an interest in the effects of climate change in the Murray-Darling Basin. What types of adaptation policies should be adopted in this important component of Australian agriculture? There is already an ‘action plan’ for addressing climate change issues generally in Australian agriculture. There is quite a bit of other literature. A global perspective is provided here while an early comprehensive report is here. An overview of US problems is here. Some additional Australian materials on the general problem facing agriculture are here and here (see also their specific report including MDB forecasts here). Analytically some of the issues being discussed in these reports have a similar structure to work on climate change and biodiversity.

Projections, first published by CSIRO in 2001, showed that by 2070, temperatures could rise between 1 °C and 6.5 °C during spring and summer in the MDB. More refined work since shows that, without explicit efforts to reduce emissions of CO2, inland regions show warming in spring and summer of between 0.5 °C and 2.0 °C by the year 2030, and warming between 0.8 °C and 6.5 °C by 2070. So the range, if anything, has slightly expanded.

Rainfall predictions are even more highly uncertain and could decrease by as much as 60% or increase by 40% by 2070 in the MDB. The changes more likely in the northerly areas are to become hotter, especially in spring. The southern and coastal parts of the MDB show less warming and a decreased shift in rainfall. It is fairly vague stuff.

There might be a payoff to the further research (now occurring) into climatic effects that pins down forecasts.

A group of UQ economists (including John Quiggin) have a paper on dealing with climate change in the MDB. They get around the problem of the range in the climate forecasts by supposing temperatures do change a lot and that rainfall decreases. I am just beginning to think about the issue but maybe this is a sensible approach. This might still yield ‘no regrets’ or ‘few regrets’ advantages even if the climatic predictions prove unnecessarily pessimistic.

Maybe too there is the need to think about the issues more generally. Clearly there is a need for water and land use reform in the MDB anyway but the prospect of climate change can raise the stakes. Supposing reforms occur (no small feat!) what types of anticipatory adaptation policies are called for to deal with a probability distribution of prospects for climate change and how far do you need to think ahead?

If static externality issues are resolved how far can free market forces be allowed to drive entry and exit from agriculture in the MDB without any need for being anticipatory?

In building up environmental resilience my hunch is that there are important synergies with efforts to conserve biodiversity.

I’ll get informed about these issues over the coming weeks (I am not pretending I am yet) and will report back. Comments, references and good hyperlinks would be appreciated.

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