Atmospheric CO 2 & Global Warming

Atmospheric Temperature and CO 2 Atmospheric Temperature and CO 2 Levels

Predicted vs Observed Temperatures (Solar Radiation)

Atmosphere Composition

The Population Explosion

The increase in atmospheric carbon dioxide is primarily due to world energy consumption and secondarily due to deforestation.

The Carbon Cycle

Fixing Carbon (Carbon Sequestration) l Photosynthesis l 6C H 2 O  C 6 H 12 O 6 + 6O 2 l Atmospheric carbon is fixed in the biosphere. l Stable exchanges 110 billion tons of carbon annually

Carbon Imbalance l Atmospheric carbon levels are at the highest level in 20 million years. l Annually between 9 and 10 billion tons MORE carbon is introduced into the atmosphere than is fixed. l Why?

Types of Carbon l Biospheric carbon and Lithospheric carbon (fossil fuels) l General balance of biospheric carbon exchange, EXCEPT for additional atmospheric carbon from deforestation l Between 1 and 2 billion tons per year. l Lithosperic carbon 8 billion tones of carbon to the atmosphere l 1 gallon of gas 5 lbs carbon (18-19 lbs CO 2 ).

2010 Carbon Emissions by Country

Carbon Emissions Per Capita

World Mapper Carbon Emissions Per Capita

Hundreds of thousands of years ago 400,000 Years of Atmospheric Carbon Dioxide Data Atmospheric CO 2 (ppm)

OK, Make it a Million Years

Causes of Global Change (population, proximate/ultimate effects) Population growth or resource over consumption? l Impact = Population Number * Per Capita Resource Use l US CO2 emissions = ca. 4 tons C/person/year l Chinese CO2 emissions = ca. 0.2 tonsC/person/year US Impact = 4 ton C /person x ca. 270,000,000 =ca. 1.1 billion tons C/year Chinese Impact =. 2 ton C /person x 1.4 billion people =ca. 0.3 billion tons C/year

What is the effect on global temperature of doubling the atmospheric concentration of carbon dioxide? The direct effect of heat absorption by the CO 2 : + 1 o C The indirect (feedback) effects: to 3.5 o C melting ice and snow increases absorption of sunlight (ice-albedo effect) warmer air holds more water vapor, another greenhouse gas warmer air results in different cloud characteristics TOTAL: to 4.5 o C

IMPACTS OF GLOBAL WARMING Threats to Food Production (Diminished Water Supplies) Human Health Impacts (Heat Waves, Infectious Disease) Wildfire Sealevel Rise Ecological Effects: Extinction Episode Comparable to K-T Boundary Spread of Invasive Species Coral Bleaching Biome Shift Northwards Climate Hot Map

Future energy policy will determine this This warming has already occurred Year

Dr. James Hansen, NASA GISS How Serious Is This? l Warming of more than 1 0 C above today’s level will make the Earth warmer than it has been in a million years. l Business-as-usual, with fossil fuel CO 2 emissions continuing to increase will mean an additional warming of 2 0 C to 3 0 C this century and will make the Earth a different planet. l At 2 0 C to 3 0 C the new sea level would be 25 meters (80 feet) higher than today.

New York City Long Beach Atlantic City Wildwood Montauk New Haven Weiss and Overpeck, University of Arizona

Sea Level +1M New York City Long Beach Atlantic City Wildwood Montauk New Haven Weiss and Overpeck, University of Arizona

Sea Level +6M New York City Long Beach Atlantic City Wildwood Montauk New Haven Weiss and Overpeck, University of Arizona

Virginia Beach Norfolk Ocean City Hampton Dover Weiss and Overpeck, University of Arizona

Virginia Beach Norfolk Ocean City Hampton Dover Sea Level +1M Weiss and Overpeck, University of Arizona

Virginia Beach Norfolk Ocean City Hampton Dover Sea Level +6M Weiss and Overpeck, University of Arizona

Wilmington Myrtle Beach Charleston Mt. Pleasant Hilton Head Savannah Weiss and Overpeck, University of Arizona

Wilmington Myrtle Beach Charleston Mt. Pleasant Hilton Head Savannah Sea Level +1M Weiss and Overpeck, University of Arizona

Wilmington Myrtle Beach Charleston Mt. Pleasant Hilton Head Savannah Sea Level +6M Weiss and Overpeck, University of Arizona

Ft. Lauderdale Daytona Beach Jacksonville St. Petersburg Fort Meyers Panama City Miami Weiss and Overpeck, University of Arizona

Sea Level + 1M Miami Ft. Lauderdale Daytona Beach Jacksonville St. Petersburg Fort Meyers Panama City Weiss and Overpeck, University of Arizona

Sea Level + 6M Miami Ft. Lauderdale Daytona Beach Jacksonville St. Petersburg Fort Meyers Panama City Weiss and Overpeck, University of Arizona

New Orleans Lake Charles Beaumont Baton Rouge Weiss and Overpeck, University of Arizona

Sea Level +1M New Orleans Lake Charles Beaumont Baton Rouge Weiss and Overpeck, University of Arizona

Sea Level +6M New Orleans Lake Charles Beaumont Baton Rouge Weiss and Overpeck, University of Arizona