ENVIRONMENT YUKON






 

Precipitation

Long-term precipitation variation

 

Significance

 

Temperature and precipitation are the two most commonly used variables to demonstrate changes in climate.

Monitoring the difference in annual precipitation from the average of the past 30 years helps us to understand the rate and extent of changes occurring in Yukon. Beyond the historic and projected trends for increasing precipitation, the variability of our climate is also expected to increase. This will mean an increase in extreme weather events (like storms) and greater fluctuations in precipitation (rain and snow).

Changes have started and are expected to continue to impact the distribution and abundance of vegetation, fish and wildlife in Yukon. Climate change is also expected to affect Yukon infrastructure, economy and communities, with water levels and extreme events playing a large part in this.

 

Fog at Samuel Glacier. Cathie Archbould.

 

 

What is happening?

Annual precipitation
  • Precipitation variability is measured by the departure from a baseline—the 30-year average from 1961 to 1990. Precipitation departures are given as a percentage change from this average (Figure 1).
  • Precipitation has increased by about six per cent over the past 50 years.
  • Summers had the largest increase in precipitation.
  • There is variability in terms of where precipitation occurs in the territory, and what time of year it occurs.

 

Figure 1: Yukon annual precipitation variability, 1950-2016

 

Projected precipitation
  • Global studies, including the 2014 Intergovernmental Panel on Climate Change Fifth Assessment Report, show that climate scenarios project a significant increase in precipitation over the next 50 years (Figure 2).
  • The three different lines in Figure 2 represent three potential precipitation futures based on emissions scenarios developed by the Intergovernmental Panel on Climate Change.
  • All scenarios show an increase in precipitation and its variability.

 

Figure 2: Yukon projected annual precipitation anomalies (A2, A1B, B1).

 

 

Taking action

 

The Government of Yukon partnered with the Northern Climate ExChange at Yukon College on developing a Yukon Climate Change Indicators and Key Findings report. This cross-sector, structured, evidence-based assessment of Yukon climate change knowledge synthesizes our current understanding, providing researchers, decision-makers and the general public with an objective overview of the climate system and any potential changes. Precipitation change and projections are two indicators presented in this report.

Reducing GHG emissions in Yukon will help to reduce the long-term negative impacts of the trends presented in this indicator.

Data quality

  • The data are exclusively from Environment and Climate Change Canada’s Climate Trends and Variations Bulletins.
  • Northern B.C. is included in Environment and Climate Change Canada’s regional separation of the data, meaning the results could be skewed towards Southern Yukon.
  • There is uncertainty in the identified trends for precipitation because data are collected over a large area with uneven coverage (particularly for winter precipitation), and because of differences in instrument methodology over time.

References

Environment and Climate Change Canada, Climate Research Branch. 2014-2015. Climate Trends and Variations Bulletins [modified 2016 Mar 22; cited 2016 Mar 3]. Available from: http://ec.gc.ca/sc-cs/default.asp?lang=En&n=A3837393-1.

Intergovernmental Panel on Climate Change (IPCC). 2014. Climate Change 2014 Synthesis Report. IPCC, Geneva, Switzerland. Available from: http://ar5-syr.ipcc.ch/.

Streiker, J. 2016. Yukon Climate Change Indicators and Key Findings 2015. Northern Climate ExChange, Yukon Research Centre, Yukon College, Whitehorse, Yukon, Canada. Available from: https://www.yukoncollege.yk.ca/research/abstracts/indicators.

 

Storm clouds over St. Elias Mountains. Derek Crowe.