EPA Global Change Research Program Climate Change: An Update on the Science Presentation to the NEG/ECP Climate Change Workshop Joel D. Scheraga National Program Director Global Change Research Program U.S. EPA March 29, 2001

EPA Global Change Research Program Key Message #1 There is a natural greenhouse effect. It keeps the Earth warmer than it would be otherwise.

Some of the infrared radiation passes through the atmosphere, and some is absorbed and re-emitted in all directions by greenhouse gas molecules. The effect of this is to warm the Earth’s surface and the lower atmosphere. Some solar radiation is reflected by the Earth and the atmosphere Solar radiation passes through the clear atmosphere Most radiation is absorbed by the Earth’s surface and warms it Infrared radiation is emitted from the Earth’s Surface The Greenhouse Effect

EPA Global Change Research Program Key Message #2 Greenhouse gases are increasing in the atmosphere because of human activities, and they are increasingly trapping more heat.

Examples of Greenhouse Gases Affected by Human Activities CO 2 CH 4 N 2 O Pre-industrial concentration288 ppmv848 ppbv285 ppbv Concentration in ppmv1800 ppbv312 ppbv 100 year Global Warming Potential Atmospheric lifetime (years) a 12 b 120 ppmv = part per million volume; ppbv = part per billion volume a No single lifetime for CO2 can be defined because of the different rates of uptake by different processes. b Defined as an adjustment time which takes into account the indirect effects of methane on its own lifetime. Sources: IPCC 1995, CDIAC (Manua Loa, Siple Station, Law Dome “DE08”, AGAGE, and Law Dome “BHD” data)

Source: Based on IPCC (1994) CO 2 Concentrations Over the Past 1000 Years

Temperature Change and CO 2 Concentrations CO 2 concentration in the atmosphere (Antarctic Ice Core) Temperature changes compared to the present temperature Thousands of years ago Temperature Change ( o C) Current Level Current Level

EPA Global Change Research Program Key Message #3 There is a collective picture of a warming world, and human activities have likely contributed.

“An increasing body of observations gives a collective picture of a warming world and other changes in the climate system.” – Global average surface temperature has increased about 0.6 o C – Temperatures have risen during the last 40 years in the lowest 8 km of the atmosphere – Snow cover and ice extent have decreased – Global average sea level has risen m during the 20 th century and ocean heat content has increased since the late 1950s – Some aspects of climate have changed (e.g., precipitation, cloud cover, temperature extremes), others appear not to have changed (e.g., Antarctic sea-ice, tropical storms, tornadoes) IPCC Third Assessment Report Working Group I Conclusions

Global Mean Land and Sea Surface Temperature: Temperatures expressed relative to average. Temperature Change ( o C) Data Source:

Top 10 Global Surface Temperatures Data Source:

Temperature Trends: 1901 to 1998 Red circles reflect warming; Blue circles reflect cooling All Stations/Trends displayed regardless of statistical significance. Source: National Climatic Data Center/NESDIS/NOAA

Precipitation Trends: 1901 to 1998 Green circles reflect increasing precipitation; Brown circles reflect decreasing precipitation All Stations/Trends displayed regardless of statistical significance. Source: National Climatic Data Center/NESDIS/NOAA

Trends of Annual Precipitation Intensity More than 2” per day 0% +2% +3% +1%

“There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities” Human influences will continue to change atmospheric composition throughout the 21 st century Global average temperature and sea level are projected to rise under all IPCC SRES scenarios – Globally averaged surface temperature: increase o C by 2100 – Global mean sea level: rise by 9-88 cm IPCC Third Assessment Report Working Group I Conclusions

EPA Global Change Research Program Key Message #4 A continued growth in greenhouse gases is projected to lead to very significant increases in global temperatures and sea level.

Surface Air Warming: GFDL Model Results for 2xCO 2 Source: Manabe and Stouffer, 1994 Degrees ( o F)

Surface Air Warming: GFDL Model Results for 4xCO 2 Source: Manabe and Stouffer, Degrees ( o F)

EPA Global Change Research Program Key Message #5 Climate change will have important consequences for human health, ecosystem health, and social well-being.

Health Impacts Weather-related Mortality Infectious Diseases Air Quality-Respiratory Illnesses Agriculture Impacts Crop yields Irrigation demands Water Resource Impacts Changes in water supply Water quality Increased competion for water Impacts on Coastal Areas Erosion of beaches Inundate coastal lands Costs to defend coastal communities Forest Impacts Change in forest composition Shift geographic rangeof forests Forest Health and Productivity Species and Natural Areas Shift in ecological zones Loss of habitat and species Potential Climate Change Impacts Climate Changes Sea Level Rise Temperature Precipitation

CLIMATE CHANGE Temperature Rise 1 (Sea level Rise 2 ) Hydrologic Extremes Urban Heat Island Effect Air Pollution Vector-borne Diseases Water-borne Diseases Water resources & food supply Environmental Refugees Heat Stress Cardiorespiratory failure Respiratory diseases, e.g., COPD & Asthma Malaria Dengue Encephalitis Hantavirus Rift Valley Fever Cholera Cyclospora Cryptosporidiosis Campylobacter Leptospirosis Malnutrition Diarrhea Toxic Red Tides Forced Migration Overcrowding Infectious diseases Human Conflicts 1 2°C by yr cm “ “ IPCC estimates Source: Jonathan Patz, 1998 HEALTH EFFECTS OF CLIMATE CHANGE

Summer Heat-Related Deaths for 5 Large Cities: Current and 2050 Climate MontrealDetroitPhiladelphiaShanghaiCairo Source: WHO, 1996 Notes: Assumes full acclimation to change climate. Does not include population growth. Current GFDL UKMO

Health Effects Acute Respiratory Illnesses and Asthma AggravationPM, O 3, NO 2, SO 2 Respiratory Hospital AdmissionsPM, O 3 Cardio-Pulmonary Effects (e.g., stroke)CO, Pb Development of Chronic Respiratory DiseasePM, O 3 CancerAir Toxics Premature MortalityPM, O 3, SO 2, Pb Reproductive EffectsAir Toxics Direct Economic Effects Lost Work DaysPM, O 3 Decreased Worker ProductivityO 3 Material Damage & SoilingPM, O 3, SO 2 Crop Yield LossO 3 Commercial Fishery Harvest LossNitrogen Deposition Forestry Yield LossO 3 Ecological Effects Acidic DepostionSO 2, NO 2 EutrophicationNitrogen Deposition Wetland PreservationNitrogen Deposition, SO 2 Known Adverse Effects of Air Pollutants

Adaptation and Other Health Concerns Measures to minimize health impacts include: –improved monitoring, surveillance, and control programs –disaster preparedness and response capability –wider use of protective technologies (sea walls and levees, water purification, vaccination) –public education –early warning systems, improved use of climate forecasts Technical solutions may themselves pose health risks –e.g., pesticides to control for insect vectors Potential reductions in biodiversity may result in losses of substances that can cure disease or relieve pain

Regional 50% Probability Estimates of Sea Level Rise in 2100 and 2200 Portland, ME New York, NY Seattle, WA San Fransisco, CA Los Angeles Charleston, SC Grand Isle, LA Miami Beach, FL Source: U.S. EPA (1995). Estimates are in inches.

U.S. Coastal Lands at Risk from a 20-inch Sea Level Rise in 2100 Source: U.S. EPA (1989) Northeast Mid-Atlantic South Atlantic S & W Florida Louisiana Rest of Gulf Coast West Drylands Wetlands Square Miles

Percent Change in People at Risk with Sea Level Rise 2050s2020s2080s % increase Middlesex University / Delft Hydraulics Note: People at risk defined as average number of people flooded per year by storm surge. Presently 10 million people are at risk, rising to about 30 million in the 2080s under reference scenario. Left bar assumes constant (1990s) protection, right bar assumes evolving protection

Current and Projected Ranges of Sugar Maple Source: Redrawn from Davis and Zabinski, 1992 Present RangeOverlapPredicted Range Prediction based on increased temperature Prediction based on increased temperature and moisture reduction

EPA Global Change Research Program Retreat of Aspen, Birch, and Pine Trees:

EPA Global Change Research Program Retreat of Aspen, Birch, and Pine Trees:

EPA Global Change Research Program Retreat of Aspen, Birch, and Pine Trees:

Low Density Medium Density High Density Source: Schneider and Root, Bobolink Bird Distribution