Anticipated Climate Change Effectsin the Pacific Northwest

Acknowledgments

• Beverly Law and students, Oregon State University• Ron Neilson and MAPSS team, Pacific

Northwest Research Station• Climate Impacts Group, University of

Washington • Chris Ringo, ecology tech team

A warming future

Northwest expected to warm 2 degrees C by the 2040s and 3.3 degrees C by the 2080s

Area burned by fire expected to double by 2040s and triple by 2080s

--Climate Impacts Group

The Oceans

Variability in el Nino-la Nina events and Pacific Decadal Oscillation (PDO) will increase, causing more intense winter storms

Short-term outlook is warmer and wetter As warming further increases, expect

increased summer drought

Snow/Rain Changes

More winter precipitation as rain Earlier spring melt means lower summer

flows 2 degrees C increase in next 20 years means

25 percent less snowpack …….a coming water crisis in the West

(Barnett et al. 2008)

Vegetation Effects

Initially growth may increase since carbon dioxide has a fertilizer effect

But with prolonged warming some areas will become more water limited, growth will decrease, and fire risk will increase

Vegetation Effects

Tree regeneration may become more difficult on lower elevation sites and better at higher elevations

Whitebark pine will be at high risk of loss due to multiple stressors

Species shifts are likely to be gradual

Climate-Informed Vegetation

Vulnerability

Climate-Induced Vegetation Shifts

Neilson, USGS Models, Veg

Synthesis

Climate-Informed Wildlife

Population Vulnerability

Species Ability to Adapt

Data source

Recall vulnerability assessment

So how do we predict future vegetation?

Proceed carefully Neilson and MAPPS group projections Look at range of possible outcomes rather

than specific future

Current Climate CGCM1

MAPSS Simulated Vegetation Distribution

Coarse-Level Physiognomic ClassificationPossible Future Woody Expansion, andCarbon Sequestration

Anticipated changes

Fire Effects

More carbon dioxide, warmer and wetter winters mean more growth and carbon accumulation

If this is followed by pronounced summer droughts, higher risk of fire

This is true Region-wide, but the change will be most pronounced in the west Cascades

Adapt to climate change by preparing for an uncertain future, not a specific one

Advice

Build planning efforts for an uncertain future, not any specific one

We are looking at various possible scenarios and using them to bracket the range of possibilities

Advice

The best climate change strategy is a rigorous , viable restoration policy to make landscapes resilient to a variety of possible futures.

We have to take climate change seriously, not because we know what the future will be, but because we don’t.

--The Economist