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British Columbia Climate Facts Historical  (1900-­‐2012  trend)  based  on  the  Provincial  Climate  Data  Set  Temperatures  have  increased  in  BC  

q  Winter  (December,  January,  February):      •  Temperatures  increased  2.1  °C  [0.6  to  3.4]  °C  over  

1900-­‐2012  [Amounts  in  square  brackets  indicate  approximate  5  to  95%  confidence  intervals].    

•  More  warming  in  the  north-­‐east  than  elsewhere.  •  Frost  days  per  year  decreased  24  [17  to  32]  days  

(over  the  period  1900-­‐2011)  q  Summer  (June,  July,  August):      

•  Temperatures  increased  1.1  °C  [0.6  to  1.5]°C  •  Summer  temperatures  have  warmed  more  or  less  

uniformly  across  BC  PrecipitaYon  appears  to  have  increased  (low  confidence).  

•  Trend  esYmates  are  very  uncertain  because  sparse  precipitaYon  observaYons  during  the  first  half  of  the  20th  century  make  it  difficult  to  esYmate  long  term  trends  reliably.  

•  Winter  precipitaYon  increased  18.3%  [-­‐0.8  to  37.7]%  over  1900-­‐2012.  

•  Summer  precipitaYon  increased  19.2%  [6.5  to  31.8]%  

 

Future  (change  between  1986-­‐2005  and  2081-­‐2100)  under  a  moderate  emissions  scenario  (IPCC  RCP4.5)  Long  term  warming  and  precipitaYon  change  will  depend  upon  future  greenhouse  gas  emissions  

•  The  pa_ern  of  projected  change  is  the  same  for  all  emissions  scenarios,  but  becomes  more  pronounced  with  greater  emissions.  

•  The  IPCC  projects  global  mean  warming  is  likely    to  be  in  the  range  1.1  °C  to  2.6°C  under  RCP4.5  

ProjecYons  for  BC  for  2081-­‐2100  under  RCP  4.5  [Amounts  in  square  brackets  indicate  the  likely  range  of  possibiliYes].  q  Winter  temperature:    

•  Warming  of  2.9  °C    [1.4  to  5.9]°C  •  More  warming  in  the  north-­‐east  than  elsewhere  •  31  [17  to  51]  fewer  frost  days  

q  Summer  temperature:    •  Warming  2.4  °C  [1.3  to  4.3]°C    •  Warming  roughly  uniform  across  BC  

q  Winter  PrecipitaYon:  •  Increase  of  10.4%  [-­‐0.2  to  25.5]%  

q  Summer  precipitaYon  •  Increase  of  2.6%  [-­‐7.0  to  9.9]%  •  Possible  moistening  in  the  north  and  drying  in  the  

southern  mainland  and  south  central  regions  

Hydrology  projecYons  show  most  interior  river  basins  are  projected  to  exhibit  increased  winter  flows,  weaker  and  earlier  spring  freshet,  and  lower  summer  flows  

For  more  informaYon:  Pacific  Climate  Impacts  ConsorYum  University  of  Victoria  www.PacificClimate.org    (250)  721-­‐6236  

Sept  30,  2013