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(Volume 1 of the Canada Country Study: Climate Impacts and Adaptation, Published by Environment Canada and British Columbia Ministry of Environment, Lands and Parks, 1997. Editors: Eric Taylor and Bill Taylor. Based on a workshop held on February 27-28, 1997 at Simon Fraser University, Vancouver, B.C.) The report can be purchased from: Environment Canada, Commercial Services, Suite 120 - 1200 West 73rd Ave., Vancouver, B.C., V6P 6H9, phone (604) 664-9091.
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Table of Contents
Executive Summary
- Temperatures are rising globally - more so in BC and Yukon than the global average.
- Further and more rapid changes are anticipated in the years to come because greenhouse gases are still increasing.
- Key aspects of climate change:
- Changes in temperature and precipitation;
- More rapid rate of change than has happened with climate changes in the past;
- More extremes in weather - including more storms and more flooding.
- Some potential impacts of climate change:
- Rising sea level for the Pacific and Beaufort coasts (greater rate for Beaufort);
- Increased spring flooding of some rivers;
- More landslides - especially in discontinuous permafrost zones;
- Changes to coastal wetland habitat;
- Changes in forest ecosystems in species composition and extent of forest;
- Possible increase in salmon and other fish productivity with increased temperatures (though this could be offset by flow and habitat changes);
- Improvement in agricultural capability of some areas;
- Effects on aboriginal lifestyles because wildlife habitats and species ranges will change.
Workshop Reports
The Yukon break-out group (which included all the participants from the Yukon: Ric Janowicz [DIAND Water Resources], Scott Smith [Agriculture Canada], Joan Eamer [Environment Canada] and Bob van Dijken [Yukon Conservation Society]) discussed two "messages" related to climate change in the Yukon:
- Peak flows in Yukon streams are projected to increase and to occur earlier. This will have impacts on natural and built systems (e.g. fish habitat; flood plain communities). Extreme flood events are likely to increase in frequency and magnitude. This should be taken into account in designing infrastructure (such as roads and bridges) and in emergency planning.
- Permafrost melt, especially in the zone of discontinuous permafrost, will result in terrain instability and impacts on streams and wetlands. This has implications for infrastructure design and will also affect natural systems. This predicted change should be taken into account in environmental assessments and in design of long-term structures.
Other important Yukon climate-change issues identified by the group were (from my notes from the meeting):
- changes in growing season, rates of change and associated ecological impacts;
- changes to ungulate populations (particularly caribou) with changes in snowfall;
- impacts on agricultural and forestry sectors (could have increased potential); and,
- coastal erosion and changes in habitat.
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Climate Model Predictions for the Yukon
- Climate models consistently predict increases in temperatures year-round and increases in snow for the Yukon.
- Winters are predicted to warm more than summers, with the winter warming being greater the farther north you go. Conversely, because of the moderating effect of the Beaufort Sea, summers are predicted to warm up more in the south and central Yukon than in the north.
- Predictions for precipitation are considered to be more uncertain than predictions for temperature change. In general, models predict increased winter precipitation for the Yukon (as with winter temperatures, the change is predicted to be greater the farther north you go). Most models predict little change in average summer precipitation levels.
- More and bigger storms are predicted for the Yukon - both winter storms and heavy summer rainfall storms, with more thunder and lightning.
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Recommendations from the Yukon Working Group:
- Public process of dialogue on climate change needed (this general recommendation came from all the groups in one form or another).
- Climate change is something that we have to start thinking about in our planning and assessment.
- We need to establish and maintain long-term monitoring of climate change and impacts of climate change - this is particularly important in the Yukon, as changes are predicted to be greater in the north and the west of the continent.
Main Report Sections
Climate Change Science
- There is a general consensus among scientists that there now appears to be "a discernible human influence on global climate" (conclusion of Intergovernmental Panel on Climate Change 1995 report)
- The main driving force is greenhouse gas increase. Ice-core records show a good linkage between temperature and carbon dioxide in the atmosphere. The level of CO2 in the atmosphere was steady at about 280 parts per million (ppm) in pre-industrial times (before 1800). It is now 360 ppm (30% higher) and is expected to increase to 500 to 900 ppm over the next 100 years.
- Models of the earth's atmosphere and circulation patterns give varying predictions of the effects of increases in greenhouse gases, and the predictions also are different for different regions. However, they all predict certain trends.
Sea Level
- Climate change is one factor affecting sea level and will contribute to rising levels in the Beaufort Sea.
- The sea is rising now along the Yukon's coast at a relatively high rate. How much this will change with warming climate depends on such factors as how much the major ice sheets in Greenland and Antarctica melt.
Glaciers
- Summer temperatures and winter snowfalls affect whether a glacier is advancing or retreating.
- In areas of high snowfall in the Yukon it is expected that the increase in snowfall will more than compensate for the warmer summer temperatures - meaning that glaciers that are advancing now will continue to advance. Some glaciers at lower elevations may start to retreat or retreat at a greater rate.
- This is in contrast to southern and eastern BC, where in general glaciers are expected to retreat at increasingly rapid rates, having great impacts on flows of rivers such as the Columbia.
- Impacts of changes in glaciers are related to increased land instability (such as debris flows) and changes in streamflow.
Permafrost and Land Stability
- In northern permafrost areas, the further decay of permafrost as a result of continued warming trends is likely to increase the occurrence of thaw-flow slides and other types of landslides. Locally, forest fires will amplify this effect.
Coastal Ecosystems
- The entire Yukon coast is subject to increased erosion and coastal flooding from predicted increased frequency and magnitude of summer storms, and from sea-level rise interacting with melting ice-rich permafrost.
- Related potential impacts are: loss of wetlands and changes in coastal species distribution.
- The Beaufort coastal zone is critical for many birds, fish and marine mammals.
- Impacts on coastal ecosystems are difficult to predict, as there are a number of factors interacting, such as changes to habitat structure, temperature and timing of the seasons.
- The productivity of the coastal Arctic waters is also related to the extent of sea ice and its annual cycle of freezing and thawing.
Biodiversity
- Habitat shifts are predicted to occur with latitude and with altitude (for example, more forest and less tundra in the Yukon - with trees expanding up mountain sides and northward). This would mean a loss of habitat for some plant and animal species and a gain for others.
- Most at risk are populations that live at the edge of their range and have very set habitat requirements, or species that do not easily move into new areas.
- A complicating factor is the rate of change - human-induced climate change is predicted to occur at an unprecedented rate. Some species adapt much more rapidly to new conditions than others. This means that certain species favoured by a shift in climate might come to dominate ecosystems.
- These habitat changes are also related to land management practices. For example, both commercial forestry practices and climate change may favour the increase of forest insect pests.
Ungulates (caribou, moose, etc.)
- One of the main aspects of climate change that is predicted for the Yukon is an increase in snow. Snow affects the movements and feeding of ungulates in the winter. The distribution and the reproductive success of many ungulates are related to snow patterns on a year-to-year basis. Long-term changes in snow are predicted to alter distributions and abundance of ungulates.
- Changes in the timing of spring are also important, as this affects the availability of food during the calving season.
Forests, Alpine and Tundra Ecosystems
- On an ecosystem level, predicted changes are: decline in wetlands (especially bogs), increased fire frequency and increased forest productivity.
- A warming climate is predicted to lead to changes in treeline (movement of forests northward and upward). This may be offset to some extent by increases in winter snowpack.
- The changes in vegetation communities in forests, alpine and tundra will all be influenced by local conditions and species mixes. Studies suggest that shrubs will dominate at the expense of smaller, herbaceous plants in alpine and tundra communities. In forests, white spruce and lodgepole pine are likely to dominate whereas black spruce is expected to become less abundant. Southern plants species will move into the area.
Fish
- Although warmer temperatures should bring increased productivity in northern spawning areas, this may be offset by deteriorating conditions in the marine environment. (Southern BC salmon stocks are predicted to decrease.)
- Some freshwater species (such as lake trout) may increase due to greater productivity in warmer waters - but there also could be deterioration in stream habitat related to changes in water flows.
Agriculture
- Increase in the length of the growing season would allow production of crops that cannot be produced now in the Yukon (especially grain).
- Moisture is also a limiting factor in the Yukon, but projected increases in annual precipitation would probably not be significant for agriculture.
- Overall the projected impact of climate change should be positive for agricultural production in the Yukon.
Aboriginal Lifestyles
- Aboriginal lifestyles are strongly tied to resources on their traditional lands. Impacts of climate change on distribution and abundance of key fish and wildlife resources would affect the economy and culture of aboriginal communities.
- In the Yukon, the best-studied example of this is the Porcupine Caribou Herd. Research has established links between climate variables and the Herd's productivity. Predicted changes in the Herd's range - increased snow depth, earlier spring and warmer summers - are projected to have detrimental effects on Porcupine Caribou numbers.
Energy Production
- The hydro-electric sector is identified as the energy sector most sensitive to climate change (because of predicted changes to stream flow).
Integration
- Stewart Cohen (Paper 20) provides an integration of identified impacts for BC and Yukon. He concludes his discussion with the statement that both:
- strategies to reduce greenhouse gas emissions; and,
- adaptation to climate change,
must be considered.
- This includes the need to:
- reduce vulnerability to extreme events;
- respond to changes in renewable resources;
- reassess land use choices;
- review the design and maintenance of infrastructure;
- understand the potential changes in risk; and,
- lengthen some planning horizons.
Greenhouse Gas Emission Reduction
- Stan Liu (Paper 21) outlines the actions on international and national scenes regarding greenhouse gas emission reductions (Framework Convention on Climate Change signed at the Rio Earth Summit 1992, and its follow-up meetings, including the upcoming meeting in Kyoto in December, 1997.)
- The commitment made by nations who signed this international agreement is to reduce greenhouse gas emissions to 1990 levels by 2000.
- Canada's additional commitment is to lower carbon dioxide emissions by 20% from the 1988 level by 2005. (This commitment was made in the Green Plan, the Liberals' Red Book, and at the first follow-up meeting to the international convention.)
- It is estimated that Canada will be 11-13% above 1990 levels of greenhouse gas emissions by 2000.
- Canada's National Action Plan was approved by the Canadian Council of Ministers of the Environment in 1993. Actions in the plan include: voluntary reduction, energy efficiency, education.
- Economic instruments and other options are being considered.
Forest Management
- Dave Spittlehouse (Paper 24) looks at forest management and how it could be adapted to take climate change into consideration. He presents a management response framework to identify issues, determine sensitivity of forests, develop management responses and monitor forest changes.
Climate Change is Everybody's Business
- In Paper 25 Stewart Cohen looks at response to climate within a regional and social-economic context.
- He presents the case for consultation and integration in planning:
"Communities can simply react to climate change when it occurs or they can prepare for the future by lengthening their planning horizons."
- Our current planning frameworks (including development, lifestyles, legal, infrastructure) are based on the assumption of a constant climate.
- A long-term vision needs to look at the broader relationship between other climate change and other global issues, such as population growth.
Policy
- Hugh Morris (Paper 26) evaluates the role of science and scientists in influencing the development of global change policy. He stresses that scientists often confuse policy-makers and the public by failing to present their results in ways that are understandable and meaningful to non-scientists.
- The development of global policies needed to deal with climate change will require the active involvement of scientists and improved communications between scientists, policy-makers and the public.
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