Tuesday, February 23, 2010

Climate Change Adaptation

I’ve talked about climate change and what we can do to reduce greenhouse gas emissions (GHG) on this blog. While it is important that we continue to reduce GHG, the reality is that climate change is happening and reducing GHG will only affect the severity of the change and not stop it. The European Union target of reducing GHG to have temperature rise 2°C above the pre-industrial temperature will still result in major changes to our environment. Increased storms and rising sea levels are some of the things that we will have to deal with. Natural Resources Canada has a great website on climate change adaptation. A section of their site called Adaptation 101 already points out the changes happening in our ecosystem. Here’s a fun fact:
The economic costs resulting from extreme weather events in Canada in the past decade (since 1996) have been greater than for all previous years combined.
Climate Change will impact how we live in Canada, but we are a rich country and will be able to adapt. Many countries will not. In Metro Vancouver, we will have to adapt. A report from Metro Vancouver identifies the following list of changes.
1. Rising Sea Levels – Sea levels are expected to rise at a rate of 2 to 9 mm per year in the Greater Vancouver Regional District. This translates to a 10 to 45 centimetres rise by 2050 and 20 to 90 centimetres by 2100. Thermal expansion of the top ocean layer combined with subsidence in the Lower Mainland by a tectonic effect and/or compaction of the delta sediment pile will be the main cause of this sea level rise. Erosion of cliffs by wave action in areas such as Point Grey will be exacerbated by such a sea level rise. Drainage and sewerage systems could also be negatively impacted in the Lower Mainland. Recreation beaches will be more costly to maintain as a result of rising seas.

2. Spring Flooding – Increased winter and early spring precipitation in the Greater Vancouver Regional District and its watersheds may mean that existing flood protection works would no longer be adequate and flood damage could be more severe and frequent near rivers and streams. Increased precipitation would also increase the load on the Lower Mainland regional sewerage and drainage system.

3. Summer Drought - Summer soil moisture will diminish in the lower Fraser Valley as temperatures rise, leading to higher summer demand for agricultural and domestic water. Stream flow in late summer and fall will likely decrease in the GVRD and its watersheds, while stream temperatures will rise. This would reduce fish survivability.

4. Landslides - Landslides and debris torrents could become more common in steep and unstable terrain in northern areas of the Greater Vancouver Regional District as winter precipitation rises. Water quality in reservoirs, fish and wildlife habitat, as well as roads and other man-made structures could be at increased risk.

5. Coastal ecosystems - Increased organic material, increased sedimentation, coastal flooding and permanent inundation of natural ecosystems will occur in low gradient, intertidal areas of the Greater Vancouver Regional District as a result of increased precipitation in winter and rising seas. Some sensitive intertidal ecosystems may not be able to migrate inland as sea levels rise due to the presence of man-made dykes. Sea level rise will also cause salt water to penetrate further inland in the Fraser River and other estuaries, resulting in changes in natural estuarine communities.

6. Forest fire and pests – Drier summer conditions in forested areas of the Greater Vancouver Regional District would increase the risk of fire. Milder winters would allow more forest pests to survive and multiply.

7. Coastal infrastructure threats - Low-lying homes, docks and port facilities may be frequently flooded at high tide in exposed areas of the Greater Vancouver Regional District during severe storms if the sea level rises significantly. Upgrading of existing dykes in low lying areas such as Richmond, Delta and Surrey could be necessary.

8. Groundwater Impacts - Sea level rise will raise groundwater levels in low-lying areas of the Fraser Valley, forcing additional expenditures on water pumping. Salt water intrusion will affect some wells.

9. Air Quality Degradation - In conjunction with the rapid urbanization, air quality may become seriously degraded in the Lower Fraser Valley and the Okanagan Valley as stagnant summer conditions conducive to poor air quality become more common.

10. Agriculture Improvement - Agriculture could expand in the lower Fraser Valley and new, higher value crops could be introduced.

11. Human Health Risks - Some parasites, such as Giardia, thrive in a warmer climate. Also, fleas and mites that are now killed off completely each winter in the lower Fraser Valley will flourish in a warmer climate.

12. Recreation – Winter recreation in the shore mountains will be affected if warmer temperatures reduce the length of the ski season.

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