How is the Climate Changing in the Prairie Provinces?

What can we expect in the future?

Elaine Wheaton

Agriculture and Greenhouse Gas/ Climate Change WorkshopSaskatoon, SK

December 11-12, 2000

Overview

• Past climate changes• Past ecosystem changes• Climate change factors• Greenhouse gas concentrations• Future expected climate changes• Future expected climate impacts and adaptations

Global Annual Surface Air Temperatures

• This observed change is unlikely to be due entirely to natural fluctuations of the climate system

1 Huang and Pollack 1999 2 WMO Bulletin 1999 3 IPCC 1996

N. American Air

Temperature Trends

(1961-1990)

Prairies’ Temperature Trend

(After Gullett and Skinner 1992)

Ecosystem Changes related to Climate

• Widespread changes in ecosystems are already occurring as affected by these climate changes

• These changes are consistent with climate change projections

For example

Long-term snow cover variations for the Western Prairies

The snow cover season has been shrinking,especially in the last 30 years

(after Brown et al. 1995)

A widespread retreat of glaciers is occurring in the

northern hemisphere

Glaciers are an important source of river flow for the prairies

(Demuth 1996)

Annual Ground Surface Temperature Change (1950 – 1990)

(MBIS, 1997

Frequency of Winter Storms in the Northern Hemisphere

Frost Free Season ….

……is Lengthening

Heating and Cooling

Degree-days for Regina

and Saskatoon

(Wilson, 1990)

Plant Growth Increased in Northern High Latitudes from 1981-1991

Associated with

• lengthening of active growing season

• earlier disappearances of snow cover

• marked warming in the spring time

• an advance of up to 7 days in the timing of the drawdown of CO2 in spring and early summer

Myneni et al, 1997 Nature 386, 698-701

Time Variations in Normalized Difference Vegetation Index (NDVI)

for Selected Latitudinal Bands

Other Ecosystem Changes

• Edith’s Checkerspot butterflies have moved north and to higher elevations

• Sachem skipper butterflies have expanded their range from N. CA to Oregon and SE Washington

• Mexican voles have expanded their range into NE Arizona and Colorado

• Prairie grasses are declining in NE Colorado and being replaced with exotic weeds

(Levy 2000)

There are many more……

Climatic Change Factors and their Effects on the Earth's Climate

Analysis demonstrates (statistically significant) that GHG’s are the dominant driver of climate changes in the past century.

(Mann et al., others)

Greenhouse Gas Time Series

CO2 Trends

Goldilock’s Earth

Balance of Evidence Suggests a Discernible Human

Influence on Global Climate

- IPCC 1996

Future Expected ClimatesClimate Models Agree that:

(for mid-latitude N. Hemisphere)

• Winter temperatures increase faster than summer temperatures

• Night temperatures rise faster than day time temperatures

• Soil moisture decreases in summer and increases in winter

• Snow cover area and duration decrease• Precipitation increases in winter, some decreases in

summer

Global mean temperature change (°C) associated with the six IS92 emissions scenarios and the four SRES scenarios. Until recently, GCM experiments generally used the IS92a emissions scenario to define the future forcing. ( Barrow et al, 1999)

0

1

2

3

1990 2010 2030 2050 2070 2090

Year

Glo

bal

-mea

n t

emp

erat

ure

ch

ang

e (°

C)

IS92a

IS92b

IS92c

IS92d

IS92e

IS92f

SRESA1

SRESA2

SRESB1

SRESB2

Global Mean Temperature Change

Projected Winter Average Temperature Change 2010 to 2039

http://www.cics.uvic.ca/

Projected Winter Average Temperature Change 2040 to 2059

http://www.cics.uvic.ca/

Projected Summer Average Temperature Change 2010 to 2029

http://www.cics.uvic.ca/

Projected Summer Average Temperature Change 2040 to 2059

http://www.cics.uvic.ca/

Comparison of Observed and Modeled Climates

General patterns and global temperatures are reasonably simulated.

CGCM1 Simulation of 20th Century Change

Expected Changes in Extreme Weather- Examples

• Thunderstorms and hail events to increase• Number of heat waves to rise• Number of cold spells to decrease• Northward shift of tornado and dust storm alleys• Droughts and floods to increase and intensify

Surprises?? Abrupt climate changes within decades have occurred before and are even more possible now

Annual Number of Hot Days -

Now and in the Future

Drought and Flood Frequencies -Now and in the Future

Some Projected Agroclimatic Futures

• Longer growing seasons• More frequent extremes – drought, floods, heat waves,

hail storms, dust storms, wind storms, etc.• Decreased snow cover area and spring re-charge• Increasing demands for water and conflicts over water• Northward expansion of insects and diseases• Decreasing air, soil, and water quality• Decreasing space heating demands, increasing air

conditioning demands

ADAPTATION

Share the Loss

Bear the Loss

Modify the Events

Prevent the Effects

Research

Education, Behavioral

Avoid the Impacts

Structural, Technological

Legislative, Regulatory, Financial

Institutional, Administrative

Market-based

On-site Operations

Change Use

Change Location

Adaptation Framework

Adaptation Research and Monitoring Needs

• Drought and frost tolerant crops• Heat stress effects on livestock• Water and soil conservation• Irrigation improvements• More fall seeding of crops• More & improved climate

information for management and planning

Adaptation Research and Monitoring Needs

• Modeling of climate-production-management relationships

• Nutrient management• Enhanced communication among

producers, climatologists, agrologists, and policy makers

• Preparation/coping with extreme events

Enhanced Monitoring SRC’s Saskatoon Climate Reference Station

(C.Beaulieu)

More Climate Impacts and Adaptation Information

Public accessible information

More Collaborative Climate Impacts and Adaptation Research

The Prairie Adaptation Research Cooperative is a facilitative, interdisciplinary research network established to understand the potential impacts of climate change on the Canadian Prairie Provinces and conduct research necessary to develop appropriate adaptation strategies.

www.parc.ca

C. Beaulieu