The CBC’s recent article Climate change in B.C.: Here’s how 2050 could look cites the Pacific Climate Impacts Consortium’s publication Climate Projections for Metro Vancouver which claims that “Global climate models project an average increase of about 3°C in our region by the 2050s”. It’s unclear where they got this figure, since the NOAA’s Climate Change: Global Temperature Projections give the range of 1.5-1.7°C.
The CBC article goes on to repeat the oft repeated 2°C narrative. The story of the 2 degree “point of no return” is based on a Proceedings of the National Academy of Sciences study described in Science Daily’s article Scientists identify climate ‘tipping points’. From that article:
Scientists analysed the climate model simulations… They found evidence of 41… regional abrupt changes in the ocean, sea ice, snow cover, permafrost and terrestrial biosphere. Many of these events occur for global warming levels of less than two degrees, a threshold sometimes presented as a safe limit. However, although most models predict one or more abrupt regional shifts, any specific occurrence typically appears in only a few models.
“This illustrates the high uncertainty in predicting tipping points,” says lead author Professor Sybren. “The majority of the detected abrupt shifts are distant from the major population centres of the planet,” says Martin Claussen, director of the MPI-M and one of the co-authors.
There will likely be drastic shifts in climate as warming occurs, and they will doubtless cause huge problems, but this is hardly the “cross the line and the earth descends into fiery hell” scenario that the media has made it out to be.
Next, the CBC article claims that sea levels will rise by 30cm (1 foot) by 2050. This seems to be at the low end of the range of predictions that have been made. Sea levels have been slowly rising over the last century without human caused increases in CO2 concentrations, so this number seems quite reasonable.
Some of the negative impacts the article identifies:
- dikes will need to be improved
- higher river temperatures may harm some fish
- flood risk will be higher
- the number of hot days will likely double, increasing air conditioning costs
- fewer pests will be killed off by cold in the winter
- the interior fire season may increase by 30 to 50 days
- growing season expanded by more than two months