Major Components PA Climate Futures Agriculture Aquatic Ecosystems/Fisheries Energy Forests Human Health Insurance Outdoor Recreation Water.

Major Components

GlobalClimate

RegionalEconomy

Economyin Rest of

World

ApproachClimate Futures

Multi-model GCM averages Two IPCC emissions scenarios

Sector impact studiesLargely based on literature review

and synthesis

“High” emissions A2 scenario

“Low” emissions B1 scenario

(Annual)

PA Climate FuturesProjections for the state

constructed using averages of outputs from 14 GCMsMulti-model mean provides a

credible simulation of PA’s 20th Century Climate, and is superior to any individual GCM

Multi-model mean is slightly too cool and wet, and slightly muted in variability on sub-monthly time scales

Pa Very Likely to be warmerAll GCM models project warming through

2100 for both emissions scenariosWarming for the next 20 years is

independent of the emissions scenarioWarming by the end of the century is

substantially dependent on the emissions scenarioA2 median projected warming about 4ºCB1 median projected warming about 2ºC

Greater Warming in Summer than Winter Means

Emissions Scenario

Period B2 A1

2045-2065 2.0ºC 2.5ºC

2080-2099 2.5ºC 4.5ºC

Emissions Scenario

Period B2 A1

2045-2065 1.5ºC 2.0ºC

2080-2099 2.0ºC 3.0ºC

PA Likely to Be WetterLess model agreement on precipitation

than warmingBut >3/4 project increased annual

precipitation through the century for both emissions scenarios

Like temperature, the change in precipitation does not vary with emissions scenario to mid-Century - but does beyond that A2 median projected increase in annual

average precipitation about 10% by 2100

Precip Increases greater in Winter than Summer

Average summer precipitation increase across all models is on the order of 0-5% during 2046-2065 and a little greater than that during 2080-2099.

Average winter precipitation increases is ~5-10% during 2046-2065 and 10-15% during 2080-2099

Some other Climate ResultsLonger growing seasons, and

fewer frost days, but also longer dry periods – soil moisture droughts a concern

Greater intensity of precipitationIncreased intensity but reduced

frequency of tropical and extratropical systems

Water ResourcesFloods:   Potential decrease in rain-

on-snow events (good news), but more summer floods and higher flow variability.

Stream temperature:   Increase in stream temperature for most streams likely (e.g., bad for trout). Streams with high groundwater inflow less affected.

Snow pack:   Substantial decrease in snow cover extent and duration.

 Runoff:  Overall increase, but mainly due to higher winter runoff. Decrease in summer runoff due to higher temperatures.   

Water ResourcesGroundwater:  Potential

increase in recharge due to reduced frozen soil and higher winter precipitation.

Soil moisture:  Decrease in summer and fall soil moisture. Increased frequency of short and medium term soil moisture droughts.  

 Water quality:   Flashier runoff, urbanization and increasing water temperatures might negatively impact water quality.

Ecosystems Will Be Increasingly Stressed

Wetlands and headwater streams in Pennsylvania are already compromised in their ability to provide ecosystem services

Climate change will increase stresses on aquatic ecosystemsIncreased stream temperaturesIncreased flow variability

Impacts will be difficult to detect because of the continuation of other stressors such as development and invasive species

AgricultureModerate warming (1 to 3ºC) could……

Could increase yields of some major field crops (corn, hay, soybeans)

Harm yields of cool-temperature adapted fruits and vegetables (potatoes, and apples) while benefiting those suited to warmer temperatures (sweet corn)

Harm American grape varieties but create opportunities for European varieties

Increase dairy production costs but increase the attractiveness of PA to southern hog and poultry producers

AgricultureMore extreme warming poses greater

problemsDroughts, pests could be problematicOutcomes for PA farmers depend not

only on climate change in PA, but what climate change does to agricultural markets and economies elsewhereWorld pricesShifts in location

ForestsSpecies composition will shift as

the climate becomes less suited to northern species and more suited to southern species

Northern Southern

American Beech Loblolly

Black Cherry Shortleaf Pine

Eastern Hemlock Common Persimmon

Red and Sugar Maple Red Mulberry

White Pine Oaks & Hickories

Forests

Like agricultureEconomic productivity could increaseBenefits to the industry will depend

on climate change impacts elsewhereDisease, invasive species, fire risks

also increase

Temperature Related Mortality

Mechanism of Impact

Direction of Impact

Level of Confidence in Direction of impact

Higher summer temperatures cause an in increase in heat-related deaths

High

Higher winter temperatures cause a decrease in cold-related deaths

High

Net impact unknown

Heat adaptations include air conditioning, warning systems; low income assistance needed

Respiratory Disease

Mechanism of Impact

Direction of Impact

Level of Confidence in Direction of impact

Higher summer temperatures cause in increased in ozone formation

High

Higher temperatures increase formation of airborne particulates

Low

Higher temperatures, higher CO2 levels and longer summer season increase prevalence of pollen and mold

Low

AccidentsMechanism of Impact

Direction of Impact

Level of Confidence in Direction of impact

Increases in flood and severe rainstorms Decreases in snow and ice storms

Low

Infectious DiseasesVector Borne: Lyme, West Nile, St. Louis

Encephalitis, Ehrilichiosis, MalariaWater Borne: Cryptosporidium, Giardia,

Campylobacter, SalmonellaAirborne: Influenza, Pneumococcus

Mechanism of Impact

Direction of Impact

Level of Confidence in Direction of impact

Higher temperatures affect range and abundance of disease-carrying vectors

Low

Higher temperatures and runoff lead to increased concentration of water-borne pathogens in surface waters

Medium

Higher winter temperatures affect incidence of pneumonia and seasonal influenza

Low

Infections Diseases

Outdoor Recreation Increased winter temperatures will shorten

the season and increase the costs of downhill ski facilities – the economic viability of the activity will be diminished

Reduced snow cover will diminish opportunities for dispersed snow-based recreation (skiing, snow

Increased stream temperatures will affect the viability of wild and to some degree stocked trout populations

Increased temperatures will increase the number of fishing days

Longer and warmer summers will increase the demand for water-based recreation

Proactive State andLocal Adaptation Policy

• Climate downscaling• Reduce emission scenario uncertainty•  Detailed sectoral modeling studies•  Storm risk assessment• Hydrologic conditions at a small

watershed scale•  Ability of already impacted systems to

accommodate climate change• Health-climate-environment

relationships

New Research is Needed to Fully Understand Impacts