Date post: | 27-Mar-2015 |
Category: |
Documents |
Upload: | carlos-dillon |
View: | 225 times |
Download: | 0 times |
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