A Climate Change Impact Assessment (CCIA) of Key Indicators and Critical Thresholds for Viticulture and Oenology in the Fraser Valley, British Columbia, Canada

Abstract

AbstractGrape growth and wine production are both closely connected with weather and climate, making anthropogenic climate change a source of great uncertainty for the grape and wine industries. To assess the impacts of climate change on viticulture and oenology in the Fraser Valley, British Columbia, Canada, where no such assessment has been published to this date, a series of key indicators and critical thresholds were selected based on their relevance to the local climatology. Trends among these indicators and thresholds were calculated over a historic period (1970-2019) and projected over the 21st century for one intermediate-emissions and one high-emissions climate change scenario. Historic trends were assessed using Environment and Climate Change Canada weather station data from Abbotsford, British Columbia. Two statistical downscaling methods were evaluated based on their ability to reproduce observed conditions in the Fraser Valley and the most effective method was used to create projections of local, daily climate change scenarios. During the historic period, temperatures increased significantly, while precipitation and moisture variables displayed insignificant trends, reflecting the trends observed across other wine regions in Canada and the Northwestern United States. Throughout the 21st century, warming is expected to continue while precipitation decreases modestly. Extreme heat is projected to become far more frequent, while extreme cold and potential frost days become rare. In the short term, modifications to vineyard and winery operations may be sufficient adaptation strategies. Over the long term, new grape varieties will most likely need to be planted in existing vineyards and suitability for cool-climate varieties may shift northward in direction or upward in elevation.