Ralph Pentland says we should avoid over-reacting to climate change, as the best policy would be to do what we should be doing anyway.
At the outset, I would like to point out that my own background is in water and environmental management. I do not profess to be an expert on climate – so my few remarks will be based as much on intuition as on science.
Let’s begin with the basics – assuming the climate forecasters are somewhere near the right ballpark. The hydrologic effects of climate change could include changes in annual, seasonal and extreme precipitation, evaporation and runoff. There could also be an earlier onset of soil drying in early summer, and decreases in soil moisture availability. And in a cold climate like ours in Canada, we could experience a decrease in the ratio of snowmelt to rain, and an increase in the rate of snowmelt in spring months.
These hydrologic changes would translate into a number of water resources effects – for example, effects on drought and flood magnitude and frequency; supply reliability; demand requirements; and water quality and ecosystem habitat conditions.
Since water tends to be both an environmental and an economic integrator, these water resource effects would impact on a broad range of socio-economic activities – agriculture, forestry, hydroelectricity, industry, municipalities, recreation, shipping, and so on.
It seems to me the first step in preparing for climate change should be in identifying the areas and activities that are likely to experience the most serious negative impacts of an increasing greenhouse effect. Areas where water resources are already sensitive to climatic variability will probably be most vulnerable to the impacts of future climate change. Generally speaking, such areas have few or many of the following characteristics:
* natural water deficits
* high societal demands
* high flood risk
* dependency on reliable seasonal supply
* sensitivity to lake levels
* decreasing water quality
* dependency on hydroelectricity
* sensitive natural ecosystems
Despite lingering predictive uncertainties, the implications for water resource systems are likely to include increased stress and more frequent failures. The apparent dilemma for water planners, managers and policy makers is whether to act on incomplete information, or to wait for more solid scientific support.
My own perception is that the dilemma is in fact more apparent than real, because the directions we should be moving to prepare for climate change are identical to those we should be moving anyway. Let me illustrate by way of a few examples:
- We should begin to seriously question the real viability and sustainability of proposed irrigation systems, and make the existing ones more water efficient, with or without climate change. Climate change may force us to do it sooner.
- We should discourage new development on flood plains and along susceptible shorelines, with or without climate change. Increasing climate variability may convince our citizens of the wisdom of that approach sooner.
- We should broaden our arsenal of weapons for combating water quality deterioration, with or without climate change. Climate change could induce us to do it sooner.
- We should price water and other environmental resources in such a way as to encourage their conservation – climate change may give us the incentive to do it sooner.
- We should do less subsidizing and more taxing of environmentally damaging activities, with or without climate change. Climate change could convince our lawmakers to do it sooner.
- Decentralized decision making, and application of user/polluter pays approaches should be practiced to the extent possible. These principles, which make sense anyway, are coming increasingly prudent with a less predictable future.
- Some claim that most countries have less water and environmental planning capability today than they had a few decades ago. To the extent that is correct, we should reverse that trend, with or without climate change.
Some have suggested massive capital works solutions – I disagree, with one small proviso. I would take climate change scenarios into account as a secondary design consideration for projects that we are building anyway. For example, it may be possible to design water management schemes, at little or no extra cost today, in such a way that they could be modified later, if necessary, in response to a changing climate.
I do not think we should even contemplate major capital works projects at this time just to deal with potential climate trends. For example, if it doesn’t make economic sense now to further regulate the Great Lakes, we should not consider building capital works merely in anticipation of lower water supplies a few decades away – the evidence simply does not support it.
In fact, I would contend that the danger of over-reacting with structural measures is significantly greater than the danger of under-reacting. Let me elaborate by way of an admittedly far-fetched example. What would happen if two or more northern circum-polar countries were to decide simultaneously to solve their emerging drought problems by diverting some of their north-flowing rivers southwards?
Some oceanographers speculate that such an eventuality would affect arctic salinity gradients and climate circulation patterns in such a way as to actually accelerate the drying of the North American Great Plains. Whether one accepts that thesis or not, I am sure most would agree that the uncertainty alone is sufficient cause for caution.
In summary, what I am advocating is that we learn a lot more before contemplating any drastic adaptive measures, and that in the meantime, we simply do what we should be doing anyway – but that we do it much sooner and much better.
And cost should not be a serious concern. If my examples are anywhere near representative, a “sooner and better” strategy would almost surely result in long-term net savings.
Ralph Pentland served as Director of the Water Planning and Management Branch in Environment Canada for 13 years, from 1978 to 1991. In that capacity, he negotiated and administered numerous Canada-U.S. and federal-provincial water Agreements, and was the primary author of the 1987 Federal Water Policy. Since 1991, he has served as a water and environmental policy consultant in many countries, and has collaborated with numerous non-governmental and academic institutions. Over the years, Ralph has co-chaired five International Joint Commission Boards and Committees. Most recently he was a member of the Government of the Northwest Territories Team negotiating bilateral water agreements in the multi-jurisdictional Mackenzie River Basin.