Local Effects of Climate Change

Have you ever wondered whether or not things like climate change are really happening? Often the problem is that there is so much information out there that it is difficult to know who to believe, who to trust as an information source.

Some people say, quite correctly, that change is just part of the natural cycle. There have been massive changes in climate before and there will be again. From ice age to desert, all parts of the planet go through these cycles. These events take place over long time scales such as hundreds of thousands or millions of years.

The difference between those natural cycles and what is happening now is that those changes happened relatively slowly. Species had time to adapt to new conditions over hundreds of generations, moving their homes as the habitat moved. What we are experiencing today is a different scenario. Climate change is happening at an accelerated rate, an unprecedented compression of time scales not seen before in Earth's long history. A recent government report, Environmental Trends in British Columbia (2002), documents these rapid changes, telling the other side of the story.

The lengthy report has dozens of contributors who use 16 major indicators to assess the effects of climate change on the health of B.C.'s environment related to humans, other animal species, and plants. The current report is an expanded version of two earlier reports done in 1998 and 2000. The 16 indicators use 64 separate measures to show current condition and, where possible, emerging trends. The information has been organized into six topic areas: Biodiversity, Water, Stewardship, Human Health and the Environment, Toxic Contaminants, and Climate Change. Taken together, these sections give an overview of British Columbia's environment and show important linkages, particularly between human activities and environmental changes.

The report indicates that habitat loss continues to be the largest factor in species decline in B.C. This is followed by concerns over air quality, risk of aquifers to contamination, surface water quality and watershed health. These issues are directly related to human health and are in need of more study, dollars and, in some cases, restoration work. The chapter on toxics is comprehensive, measuring several chemical compounds across species and decades.

The climate change section begins with a discussion of greenhouse gasses, and it's no surprise that automobiles account for 42% of the total emissions province-wide. If present trends continue, B.C.'s greenhouse gas emissions are expected to increase 38% by the year 2010, the third largest rate in Canada.

The effects of these emissions are part of a global pattern, and the local effects are not evenly spread around B.C. On the coast, average temperatures have risen about the same as the global average, .5 to.6 degrees C. Here in the Chilcotin-Cariboo, the rise has been twice the global average, or about 1.1 degrees C! The report states "These trends are based on 100 years of data collection and are likely the result of climate change."

1.1 degrees C doesn't sound like much. However, the effects of this rise in temperature are felt throughout all the ecosystems: receding glaciers in the coast mountains bordering the western Chilcotin, warmer winters, earlier spring break-up of the Fraser basin, warmer water temperatures, and reduced soil moisture. In many areas of the Chilcotin-Cariboo, ranchers are feeling the effects of low rainfall / low snow conditions that have been getting progressively worse for the last several years.

These physical changes affect the plants and animals that depend upon them. The Mountain Pine beetle epidemic is a local manifestation of the things that rapidly change when the historic temperature system is changed for just a few years.

Less obvious is the effect on the Fraser River watershed. The larger part of the annual discharge from the river is happening earlier than it did 90 years ago. Fully one half of the annual discharge is now occurring 9 days earlier, advancing at the rate of 9 to 11 days per century. This means that increased snow melt earlier in the spring is producing greater early runoff, stealing water from late summer and early fall, lowering river levels and water tables. The lower river levels cause a rise in average water temperature resulting in reduced water quality.

As the air temperature increases, so does the water temperature in the Fraser River. From 1953 to 1998 average water temperature rose by 1.1 degree C. Late Sockeye salmon runs are most affected by this temperature rise. Migrating summer Sockeye prefer colder water temperatures than other salmon species. Spawning at over 150 sites in the Fraser system, Sockeye are regularly experiencing a 50% or greater mortality rate in some of their migrations. There are, of course, always exceptions to any trend such as the increased migration this year on the Adams River, but, on average, the warmer water can speed up the salmon's metabolisms creating stress, exhaustion and higher infection rates. It is for reasons like these that 1/3 of B.C.'s fish species are classified as Threatened or Endangered. (The Provincial Red List)

The report is far-ranging, as a glance at its index shows. Everything from Dragon Lake whitefish to Beehive burners is examined for survival expectation and effects on the ecosystems we live in. While not all is doom and gloom, the report is a sobering reminder of what is happening all around us. It is also a detailed analysis of what the causes are and what we can do here locally to mitigate the impacts on species and ourselves.

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The Other Side of the Story

- a series of articles by Dave Neads on conservation-related topics

Local Effects of Climate Change

About Us • Public Education • Species at Risk • Projects • Other Activities • Membership