Case studies

Assessing Vulnerabilities: Climate Change Scenarios for Park Management Decisions

Climate change adds greater risk and uncertainty to management decisions. This section describes the process through which climate change scenarios were developed for Mt. Robson Provincial Park. The intent of this step was to use easily available Global Climate Change Models to develop climate change scenarios. These could, in turn, be used to develop future scenarios for forest ecosystems and disturbance patterns and potentially inform future management interventions.

The starting point in the development of climate change scenarios was to document the potential change in key climate variables. Based on an understanding of the main ecosystem management issues in Mt. Robson Park, the main variables of interests are future climate effects on:

  • the type, range and distribution of forest ecosystems and tree species, and

  • the characteristics of forest disturbance regimes (i.e., wildfire and mountain pine beetle).

The UKCIP framework suggests the use of a general checklist approach to determining which climate variables to include in a climate change risk assessment. The next step, therefore, was to review a list of climate variables generally available from global circulation models (GCMs) and selected those thought to have the largest driving influence on forest ecosystems and disturbance regimes. These include:

  • Mean Temperature (annual and by season)
  • Mean Extreme Minimum Temperature (by month during the cold season)
  • Mean Precipitation (annual and by season)
  • Mean Soil Moisture (annual and by season)
  • Mean Wind Speed (annual and by season)
  • Mean Relative Humidity (annual and by season)

Future change projections in the selected climate variables were derived from the results of a range of GCMs run under a range of future greenhouse gas emission scenarios. This approach, which applies methods generally in accordance with the IPCC Data Distribution Center guidelines on the use of scenario data for impacts and adaptation assessments (IPCC-TGCIA, 1999), provides an opportunity for identifying both potential trends and the full range of uncertainty around them.

All data was extracted using tools provided by the Canadian Climate Impacts and Scenarios project website at: www.cics.uvic.ca/scenarios/. This source provides access to a range of GCM results. For each climate variable analyzed, the following specific inputs for Mt Robson Park were used:

  • Geographic Reference
  • Time of Year
  • Emissions Scenarios

From the overall database of downloaded results –which varies from 8 to 25 predictions depending on the climate variable since not all GCMs calculate all variables – the full “envelope” of scenario results for each time slice was charted. Each climate variable range envelope was examined over time to interpret both potential trends and the magnitude of uncertainties.

The table below provides a summary of climate change scenario results for key climate variables that influence forest ecosystems and disturbance regimes in Mt. Robson Park. The trends and envelope ranges found here are generally consistent with those reported by the IPCC for northern hemisphere (IPCC, 2001a).

Table 2: Summary of change scenarios for selected climate variables

Variable Focus Period Range of Magnitude/Direction of change
Mean Temperature Annual +2.2° to +7.9°C
Summer Season +2/2°C to +7.4°C
Mean Extreme Minimum temp Cold season months (Dec, Jan, Feb)
+1°C to +11°C
Mean Precipitation Annual -2% to +17%
Summer season -28% to -13%
Mean Soil Moisture Annual -1% to -5%
Spring Season
Summer Season		 0% to -11%
-1% to -4%
Mean Wind Speed Summer Season 0% to -16%
Mean Relative Humidity Summer Season 1% to -13%

**Note: Long-term trends (i.e. the 2080 results) are used as the basis of this summary and the specific focus periods selected for each variable are those hypothesized to have a significant influence on the forest ecosystems and disturbance regimes.

It is important to bear in mind the important limitations in the application of GCM-derived results for impact and adaptation planning. Some of the main ones include:

  • The course scale of the results (between 250-600km, and the challenges of scaling down);
  • The difficulty of predicting extreme events;
  • Greater confidence in some outputs (e.g., temperature and precipitation) over others (e.g., soil moisture).

From an adaptation planning perspective, the primary challenge is to incorporate the potential trends in key climate variables while simultaneously recognizing the inherent uncertainties associated with GCM-derived predictions. The next section sets out the process through which future scenarios for forest ecosystems and disturbance patterns were developed based on the climate change scenario results and relevant research studies.

 ......more