Climate Change Impacts in Pennsylvania

Brent YarnalDepartment of Geography

Penn State University

Overview

Supporting science Present & future climate

context Key climate impacts Some affected sectors

www.northeastclimateimpacts.org/pa

October 2008

2000

US National Assessment of Climate Change Impacts Union of Concerned

Scientists

http://www.int-res.com/abstracts/cr/v14/n3/

Climate is changing across PA

In the 20th century: Temperature increased 0.5°F Rainfall increased 5-20%

Since 1970: Temperature increased ~0.15°F

per decade Annual days over 90°F increased Winter snowpack decreased

(c) Brian A. Morganti / www.stormeffects.com

Source: IPCC 2001

HIGHER

A1FI (940 ppm)

LOWER

B1 (550 ppm)

Further warming depends on emissions

Current global emissionsRecent emissions

1990 1995 2000 2005 2010

CO

2 E

mis

sion

s (G

tC y

-1)

5

6

7

8

9

10Actual emissions: CDIACActual emissions: EIA450ppm stabilisation650ppm stabilisationA1FI A1B A1T A2 B1 B2

1850 1900 1950 2000 2050 2100

CO

2 E

mis

sion

s (G

tC y

-1)

0

5

10

15

20

25

30Actual emissions: CDIAC450ppm stabilisation650ppm stabilisationA1FI A1B A1T A2 B1 B2

20062005

2007

Key climate changes Higher temperatures More extreme heat More precipitation More severe storms More floods More droughts

2010-2039 2040-2069 2070-2099

Temperature change above 1961-1990 average

Projected temperature changes for PA

Changes in average summer heat index

Changes in average summer heat index

In the next several decades: Doubling in days over 90°F in

southern PA

By mid-century: 50 days per year over 90°F in

southern PA

By late century: Entire summer with highs over 90°F

in southern PA

Days with extreme heat

Precipitation 20th century

Annual average precipitation rose 15% (6 inches)

Future projections Trend continues under either

emission scenario

Spring rainfall under thehigher-emissions scenario

Hotter summers mean more evaporation, less soil moisture

Droughts projected every 1-2 years in many areas

Summer drought

Key sectors affected by climate change

Agriculture Forestry Water & water resources Ecosystems Human health Recreation

New opportunities

New risks & costs

iStockphoto.com/Kalulu

Agriculture & climate change

iStockphoto.com/lissart

©iStockphoto.com/Bronwyn8

Crops vulnerable to rising temperature

iStockphoto.com/claylib

USDA NRCS

Milk production declines in higher-emissions future

Forests

Forests migrate Productivity increases

Dominant forest types for a doubling of CO2

Black Cherry

Lower emissions: 50% of habitat lost

Higher emissions: 80% of habitat lost

Ecosystems

Weakened ecosystems at risk

Ecosystem functions impaired

Biodiversity decrease

Bird habitat

25% reductions in forest habitat for Ruffed grouse American goldfinch White throated sparrow

iStockphoto.com/Flatcoater

iStockphoto.com/BirdImages

Jupiter Images

Water & water resources

Uncertain water quantity

Seasonal shift in streamflow

Increased intense rainfall

Decreased water quality

Projected changes in Susquehanna River flow

Human health

Heat mortality increase Water-borne disease

increase Vector-borne disease

increase

Extreme heat – Harrisburg

Pollen allergens

Higher temperatures + higher CO2 levels more pollen allergen production

American Academy of Allergy, Asthma & Immunology

Jupiter Images

Tony Tremblay

James Estrin/The New York Times/Redux

Air quality

Impacts on winter recreation

Loss of ski industry Loss of snowmobiling

iStockphoto.com/MentalArt

Snow cover

Geoff Kuchera

Snowmobiling

iStockphoto.com/N8K