Climate Change Trends for the Northern Rockies

Jessica HalofskySchool of Environmental and Forest Sciences, University

of Washington, Seattle, WA

Presenting assessments developed by:Linda Joyce, Charlie Luce, Jeff Morisette, Darrin Sharp, John

Stevenson, and Marian Talbert

Northern Rockies Adaptation Partnership

The Northern Rockies Adaptation Partnership

Science-management partnership with the goals of:

• Increasing climate change awareness

• Assessing vulnerability of natural resources

• Developing adaptation strategies and tactics

The Northern Rockies Adaptation Partnership

Included assessments for:• Climate• Water• Fisheries• Vegetation • Disturbance• Wildlife

• Recreation• Cultural

heritage• Ecosystem

services

The Northern Rockies Adaptation Partnership (NRAP) Assessment Area

Northern Rockies Adaptation Partnership

Outline- Historical and projected climate for the NRAP

region

- Central sub-region specific climate information

- Expected changes in hydrology

Northern Rockies Adaptation Partnership

Northern Rockies Adaptation Partnership

Historical Climate Data come from:

• Maurer et al. dataset (2002)

• PRISM (2014)

• TopoWx

Modeled climate data come from:

• CMIP5 - Coupled Model Intercomparison Project Data

• Representative Concentration Pathways (RCP): 4.5 and 8.5

• With Bias Correction and Spatial Disaggregation (BCSD) statistical downscaling algorithm (Wood et al. 2004)

• Looking at “normal” (~30 year averages) for 1979-2009, 2030-2059, and 2070-2099.

The NRAP Climate Summary Chapter used…

Future temperature

projections for the NRAP

assessment area

Future precipitation

projections for the NRAP

assessment area

Future climate in the Central Subregion

Sits at the boundary between the warm,

wet, maritime airflows from the

Pacific Ocean, and the cooler, drier

airflows from Canada

Northern Rockies Adaptation Partnership

Central SubregionHistorical Climate

Statistically significant warming:

Tmax = 0.11 °F/decade

Tmin = 0.23 °F/decade

No significant trend in precipitation.

4km PRISM data

CMIP5 climate models project continued

warming, with emissions a major

uncertainty (RCP 8.5 vs RCP 4.5).

Tmax +5-11 °F by 2100, as compared to 1950-

2012.

CMIP5 climate models project continued

warming, with emissions a major

uncertainty (RCP 8.5 vs RCP 4.5).

Tmin +6-12 °F by 2100, as compared to 1950-

2012.

Projections for precipitation are

less certain, but it will probably be

slightly wetter on an annual basis.

Central SubregionMaximum

Temperature

Warmer in all seasons

Central SubregionMinimum

Temperature

Warmer in all seasons

Central SubregionSeasonal

Precipitation

Suggestion is for drier summers; wetter winters and springs; fall about the same.

Central Subregion Summary

• Over the last 100 years, Tmin increased more than Tmax.

• Tmax is projected to rise from 5 to 11 degrees F and T min from 6 to 12 degrees F over the next 100 years.

• Projections for precipitation have greater uncertainty than temperature.

• Seasonally, projected winter Tmax rises above freezing (32 oF) in mid-century.

• Summer temperatures will likely increase, and precipitation may decrease.

Northern Rockies Adaptation Partnership

Climate HydrologySnowGlaciersStreamflowSoil Water -> Trees

Declines in Mountain Runoff 1948-2013

Frac

tio

nal

Ch

ange

in L

ow

est

Qu

arti

le 1

94

8-2

01

3

Luce, Abatzoglou, Holden 2013

Orographic Precipitation

Future Wind Changes – from GCMs

20 of 24 models show a decline for the region studied!

Luce, Abatzoglou, Holden 2013

Snow

Fraction of Nov-Mar PrecipitationThat is still snow on April 1

3°C Temperature Increase

April 1 SWE Sensitivity

3°C Temperature Increase

Residence Time Sensitivity

Percent Change in Snow Residence Time

Grinnell GlacierGlacier National Park, MT

USGS Repeat Photography Projecthttp://nrmsc.usgs.gov/repeatphoto/

T. J. Hileman photoCourtesy of GNP Archives1938 20091981 1998Carl Key photo

USGSD. Fagre photo

USGSLindsey Bengtson photo

USGS

Oblique view of Grinnell Glacier taken from the summit of Mount Gould, Glacier National Park. The relative sensitivity of glaciers to climate change is illustrated by the dramatic recession of

Grinnell Glacier while surrounding vegetation patterns remain stable.

Runoff

Kormos et al., in prep

Reduced Low Flows

Watersheds in NRAP

Mean Annual

Flow

% Change

Mean Summer

Flow

% Change

Center of Timing of

Streamflow(Days)

Δ Days

1.5-Year Flood

Magnitude (Bankfull)

% Change

• Snow will not last as long• April snowpack will mostly decline• Glaciers at extreme risk• Less water in summer

- Lower lows- Earlier center of timing

• Annual flows uncertain• More frequent flood occurrence in

winter vs. spring- Flood magnitude uncertain

Summary