In praise of adaptation
Reader Taust contributed to the Great Shave Appeal, asking in return for 250 words in praise of adaptation to global warming. This isnâ€™t as hard as it might seem since a large part of my research work is focused on exactly this issue. The only problem is that I find I have to write more than 250 words. Anyway, here is the promised post.
The responses to global climate change have been characterized as â€˜mitigate, adapt, or sufferâ€™ (http://news.bbc.co.uk/2/hi/business/6302019.stm Weber 2007). Whatever level of mitigation takes place for the world as a whole, and whatever our contribution, global warming is bound to continue for decades to come, probably at rates faster than we have observed so far. So, for any given level of mitigation, the choice comes down to â€˜adapt or sufferâ€™.
A lot of adaptation will take place as a result of individual decisions. Since my area of research is water use in the Murray-Darling Basin, Iâ€™ll use this example to illustrate the point.
It is still unclear whether the drying trend observed in much of Australia over the last decade or more is the result of global change or of some unexplained multi-decade fluctuation in our local climate. It is clear, however, that the drought has been exacerbated by higher evaporation rates caused by global warming. Regardless of the precise mixture of causes, it no longer makes sense for farmers and policymakers to plan on the basis of the relatively wet conditions experienced between about 1950 and 1990, or even on distributions based on the historical record that goes back to the late 19th century. Rather, prudence requires polciies that can deal with a hotter, drier climate.
This shouldnâ€™t mean heavy-handed attempts to demonise particular crops such as rice and cotton. But it does mean that the political equilibrium of the past, in which irrigation policy was driven by the patronage-based politics of the National Party, can no longer be sustained. All water users must face an effective price that reflects the full social cost of water use, noting that this cost will vary from season to season. To make this happen, governments need to enter the water market and buy irrigation rights back from farmers to deliver sustainable environmental flows and adequate water for urban users.
How will this affect farmers? For those who were already planning on retiring, or moving out of irrigated agriculture, a higher price for their water rights will be an unalloyed benefit. Others will face the necessity of economising on water, either by increasing the physical efficiency of their systems or by changing their production patterns.
In particular, successful adaptation to climate change will require flexibility. With more frequent and prolonged drought, access to reliable high-security water will become more difficult and expensive, and justifiable only for high-value horticultural crops. Farmers who can take advantage of high flow years, while riding out years when no irrigation water is available, will be better placed to prosper in the new environment.