Jim Shortle, Penn State University March 24, 2010

Major Components

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

Economy in Rest of World Global Climate Regional Economy

Approach

 Climate Futures  Multi-model GCM averages  Two IPCC emissions scenarios  Sector impact studies  Largely based on literature review and synthesis

Emissions Scenarios

“High” emissions A2 scenario “Low” emissions B1 scenario

PA Climate Futures

 Projections for the state constructed using averages of outputs from 14 GCMs  Multi-model mean provides a credible simulation of PA’s 20 th 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 warmer

 All GCM models project warming through 2100 for both emissions scenarios  Warming for the next 20 years is independent of the emissions scenario  Warming by the end of the century is substantially dependent on the emissions scenario  A2 median projected warming about 4ºC  B1 median projected warming about 2ºC

Greater Warming in Summer than Winter Means

Period 2045-2065 2080-2099 B2

Emissions Scenario

A1 2.0ºC 2.5ºC 2.5ºC 4.5ºC Period 2045-2065 2080-2099 B2

Emissions Scenario

A1 1.5ºC 2.0ºC 2.0ºC 3.0ºC

PA Likely to Be Wetter

 Less model agreement on precipitation than warming  But >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 Results

 Longer growing seasons, and fewer frost days, but also longer dry periods – soil moisture droughts a concern  Greater intensity of precipitation  Increased intensity but reduced frequency of tropical and extratropical systems

Water Resources

    Floods: 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 Resources

   Groundwater: 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 ecosystems  Increased stream temperatures  Increased flow variability Impacts will be difficult to detect because of the continuation of other stressors such as development and invasive species

Agriculture

Moderate 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

Agriculture

 More extreme warming poses greater problems  Droughts, pests could be problematic  Outcomes for PA farmers depend not only on climate change in PA, but what climate change does to agricultural markets and economies elsewhere  World prices  Shifts in location

Forests

Species composition will shift as the climate becomes less suited to northern species and more suited to southern species

Northern

American Beech Black Cherry Eastern Hemlock Red and Sugar Maple White Pine

Southern

Loblolly Shortleaf Pine Common Persimmon Red Mulberry Oaks & Hickories

Forests

Like agriculture  Economic productivity could increase  Benefits to the industry will depend on climate change impacts elsewhere  Disease, 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 Higher winter temperatures cause a decrease in cold-related deaths High High Net impact unknown Heat adaptations include air conditioning, warning systems; low income assistance needed

Respiratory Disease

Mechanism of Impact

Higher summer temperatures cause in increased in ozone formation Higher temperatures increase formation of airborne particulates Higher temperatures, higher CO2 levels and longer summer season increase prevalence of pollen and mold

Direction of Impact Level of Confidence in Direction of impact

High Low Low

Accidents

Mechanism of Impact

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

Direction of Impact Level of Confidence in Direction of impact

Low

Infectious Diseases

 Vector Borne: Lyme, West Nile, St. Louis Encephalitis, Ehrilichiosis, Malaria  Water Borne: Cryptosporidium, Giardia, Campylobacter, Salmonella  Airborne: Influenza, Pneumococcus

Infections Diseases

Mechanism of Impact

Higher temperatures affect range and abundance of disease carrying vectors Higher temperatures and runoff lead to increased concentration of water-borne pathogens in surface waters Higher winter temperatures affect incidence of pneumonia and seasonal influenza

Direction of Impact Level of Confidence in Direction of impact

Low Medium Low

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 and Local Adaptation Policy

   Ag cultivars and practices Forest management practices – cultivated forests with facilitated regeneration  Institutions and policies for water management in an environment in which water is increasing scarce and variable  Land use planning and building codes  Restoration of aquatic ecosystems such as streams and wetlands wherever possible Expansion of public outdoor recreation facilities

New Research is Needed to Fully Understand Impacts

• • • • • 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