Climate Change Impacts on Georgia’s Natural Resources

Steven McNulty, Ph.D.

Research Ecologist

USDA Forest Service

Raleigh, NC

Global change impacts range from the certain to the unknown

Certain change

Atmospheric CO2 is increasing and will continue to increase for the foreseeable future due to human emissions of fossil fuel and land clearing

Northern Hemisphere Carbon Emissions

Source: Climate Change Impacts on the US, NAST, 2000

Atmospheric CO2 Concentrations

Source: Climate Change Impacts on the US, NAST, 2000

Very Likely Impacts In Georgia Forests

Increased Population

Increased Fire Fuel loads

Increased Air Temperature

Atmospheric CO2 Concentrations

Source: Climate Change Impacts on the US, NAST, 2000

Northern Hemisphere Surface Temperature

Source: Climate Change Impacts on the US, NAST, 2000

“..model estimates that take into account both greenhouse gases and sulphate aerosols are consistent with observations over this period”

Stott et al, Science 2000

Simulated Temperature over the US

Source: Climate Change Impacts on the US, NAST, 2000

Total Population 1990 (NPA)

Total Population 2045 (NPA)

Increase (%) in Population from 1990 to 2045 (NPA)

Total Down Woody Material (Mg/ha)for mixed hardwood & coniferous tree species

based on 2001-2002 FIA P3 county data

Note: two counties have no data available (depicted in white)

Likely Impacts On Georgia Forests(with and without climate change)

Inter-annual precipitation variability

Percent of the continental US with a much above normal proportion of total annual precipitation from 1-day extreme events more than 2 inches

Karl et al. 1996

Uwharrie National Forest Current Soil Erosion Map

Areas of Soil Erosion By 2030 On UNF

Likely Impacts On Georgia Forests(with and without climate change)

Water supply Stress

Water Demand (Use)

12%

8%

39%

41%Domestic

Industrial

ThermoEle

Irrigation

Water Availability

Supply Demand

Climate Land use change

Population

Water Supply Stress Index (WSSI)

WSSI = Total water demand from all sectors –rechargeTotal water supply (PPT + ground water)

Change in Water Stress (WSSIR)

to assess relative change in WSSI between the base year water stress (1990) and another year water stress

100*)1)( -WSSI1990

WSSIdWSSIRd =

Georgia Water Stress

• Hot/Dry year (2043) with ground water available

• Hot/Dry year (2043) without ground water available

• Warm/Wet year (2045) with ground water available

• Warm/Wet year (20450 without ground water available

Mean Temperature Predicted by Had2CMSul for 2043

Hot dry year

Total Precipitation Predicted by Had2CMSul for 2043

Hot dry year

Mean Temperature Predicted by Had2CMSul for 2045

Warm wet year

Total Precipitation Predicted by Had2CMSul for 2045

Warm wet year

Water Supply Stress Index for 2045

wet year with groundwater

WSSI Ratio for 1990:2045wet year with groundwater

Water Supply Stress Index for 2045

wet year with NO groundwater

WSSI Ratio for 1990:2045 wet year with NO groundwater

Water Supply Stress Index for 2043dry year with groundwater

WSSI Ratio for 1990:2043 dry year with groundwater

Water Supply Stress Index for 2043 dry year with NO groundwater

WSSI Ratio for 1990:2043 dry year with NO groundwater

Likely Impacts In Georgia Forests(with and without climate change)

Extended growing season and warming

The increase in growing season length over the last 50 years averaged for eight stations in Alaska having the longest and most consistent temperature records.

PEcon Hardwood Volume by FIA Survey UnitHad2CMSul Climate Scenario (2000)

PEcon Hardwood Volume by FIA Survey UnitHad2CMSul Climate Scenario (2025)

PEcon Hardwood Volume by FIA Survey UnitHad2CMSul Climate Scenario (2050)

PEcon Harvest Volume by FIA Survey UnitHad2CMSul Climate Scenario

Natural Pine, Mixed Pine and Hardwoods (2000)

PEcon Harvest Volume by FIA Survey UnitHad2CMSul Climate Scenario

Natural Pine, Mixed Pine and Hardwoods (2025)

PEcon Harvest Volume by FIA Survey UnitHad2CMSul Climate Scenario

Natural Pine, Mixed Pine and Hardwoods (2050)

Timberland Acreage Shift in Georgia 1993 - 2040: No Climate Change Baseline

Timberland Acreage Shift in Georgia by 2040 with Had2CMSul Climate Change

> 25% DECLINE

5%-25% DECLINE

<5% CHANGE

5%-25% INCREASE

Timberland Acreage Shift 1993 – 2040: No Climate Change Baseline

Timberland Acreage Shifts by 2040 Due to Hadley Climate Change

5%-25% DECLINE

<5% CHANGE

5%-25% INCREASE

Unlikely Impacts In Southeastern Forests(dependent of climate change)

Slash pine

Loblolly pine

Iverson et. al GTR NE265

Sweetgum

Iverson et. al GTR NE265

Longleaf pine

Unknown Impacts In Southeastern Forests(dependent of climate change)

Increasing CO2 on forest growth

Insect and disease impacts

Integrated stress impacts