Changing climate brings problems and opportunities.

Although no one fully understands the consequences of climate change, there is little doubt it is already occurring. Evidence from Saskatchewan weather records dating back 100 years shows a significant increase in annual average temperatures throughout the province.

At Swift Current, for example, the annual average temperature has risen 2.5[degrees] C since 1895, when record keeping began. While 2.5[degrees] may not sound significant, a few degrees difference in annual average temperature can have a substantial impact on primary industries such as agriculture and forestry. We need only think of the recent drought and forest fires and the resulting costs to the economy.

It is likely that the effects of climate change will be very noticeable in urban areas, mainly because cities are centres of population, wealth, infrastructure and communications. Climate impacts, such as major storms, snowfalls and droughts, are already significant for cities--and costly. These impacts are expected to increase as the climate warms.

Most discussion of climate change focuses on mitigation strategies--how we prevent it. As we come to realize that change is already underway, people are also talking about ways to adapt. Climate change could affect every aspect of urban life, from transportation to water and sewer systems to health. Understandably, we focus on the problems, but adaptation will involve significant opportunities as well.

Transportation will be one area in which problems and opportunities coincide. Climate change has already increased the frequency of the freeze and thaw cycle. One consequence is the deterioration of road surfaces and the proliferation of potholes. Few problems are more annoying for motorists, and since we anticipate that this problem will increase, a company that can devise methods to make pavement more durable could find its services in demand.

One of the most crucial areas to be effected by a changing climate is water. Both drought and flood are normal occurrences in Saskatchewan, but the frequency of both is likely to increase. In drought years, river flows will be substantially diminished. This will result in two problems. First, water for municipal use will likely be limited both in quantity and quality. Second, it may not be possible to rely on rivers to dissipate wastes.

Again, adaptation will create opportunities. Already, cities are looking at tertiary treatment of sewage wastes, which significantly lowers the need to discharge wastes into waterways. Opportunities will exist to design and build more effective treatment systems.

Major storms with heavy rain or snow can trigger floods that overwhelm the capacity of the storm sewer system. Such extreme events occur in many cities, perhaps every 10 or 25 years. Climate change could increase the frequency of floods. While it may not currently be cost prohibitive to install storm sewers capable of handling a 10- or 25-year flood, with more floods projected, larger sewers will be indispensable. Many municipalities are already adapting, by installing larger capacity systems into new subdivisions and upgrading capacity in older neighborhoods as part of the regular service cycle.

Climate change is beginning to have significant effects in areas such as health. New diseases, such as the West Nile virus, are worrisome. The impacts of these types of diseases could have far-reaching and unexpected consequences. In a warmer climate, particulate from car exhaust or industrial sources will become a larger concern due to the greater problems for people with allergies or asthma, for example. Pollution can even inhibit the growth of trees that have been invaluable for improving urban microclimates.

As in everything, climate change involves positive and negative impacts. If we can learn to adapt to the changing climate, the negative impact of climate can be reduced. Understanding of this issue is growing, and a forward thinking business sector can play an important role in assisting Saskatchewan's cities to adapt and prosper in a changing climate.

Virginia Wittrock is a Climatologist/ResearchScientist with the Saskatchewan Research Council.