© 2007, John Wiley and Sons, Inc. Physical Geography by Alan Arbogast Chapter 9 con’t Global Climate Change Lawrence McGlinn Department of Geography State University of New York - New Paltz

© 2007, John Wiley and Sons, Inc. Global Climate Change Major environmental issue Highly politicized Vast majority of climate scientists agree global change is occurring Vast majority also agree it is due to anthropogenic influences

© 2007, John Wiley and Sons, Inc. Global Temp Change since 1880

© 2007, John Wiley and Sons, Inc. Causes of Climate Change Variations in the Earth’s orbital characteristics Atmospheric variations in greenhouse gases Volcanic eruptions Variations in solar output Humans

© 2007, John Wiley and Sons, Inc. Variations in the Earth’s orbital characteristics The Milankovitch theory Cyclical variations in three of the Earth’s orbital characteristics Eccentricity Rotation Tilt Vary the amount of solar radiation that reaches the Earth’s surface

© 2007, John Wiley and Sons, Inc. Milankovitch Cycles

© 2007, John Wiley and Sons, Inc. Greenhouse Gases Human activities are enhancing the Earth’s natural greenhouse effect Carbon dioxide, methane, nitrous oxide, CFCs, and water vapor Greenhouse gases are transparent to sunlight but opaque to longwave radiation

© 2007, John Wiley and Sons, Inc. Carbon Cycle Carbon dioxide (CO 2 ) traps longwave radiation Carbon in all living things It moves among reservoirs – only 1% actively in cycle at any one time Reservoirs include: atmosphere, marine sediments, plants, animals, coal deposits, etc. Humans have accelerated transfer from deposits to atmosphere

© 2007, John Wiley and Sons, Inc. Carbon Cycle (Billions of Metric Tons)

© 2007, John Wiley and Sons, Inc. Atmospheric Carbon Dioxide Variations

© 2007, John Wiley and Sons, Inc.

Carbon Dioxide Atmospheric CO 2 levels began rising during the Industrial Revolution Tremendous fossil fuel burning and heavy deforestation increased CO 2 levels – this trend continues CO 2 is responsible for 64% of global warming

© 2007, John Wiley and Sons, Inc. Carbon Dioxide Amounts This represents a 54% increase in your lifetime.

© 2007, John Wiley and Sons, Inc. Carbon Dioxide Prior to 20 th century, CO 2 levels in the atmosphere ranged from 180ppm to 300ppm over past 650,000 years. Prior to Industrial Revolution in 18 th century, CO 2 at 280 ppm. In 2005, atmospheric CO 2 reached 379ppm Increasing at rate of 2ppm/year

© 2007, John Wiley and Sons, Inc. Carbon Dioxide Sources

© 2007, John Wiley and Sons, Inc. What are the Fossil Fuels? 98 tons of prehistoric plant matter for each gallon of gasoline

© 2007, John Wiley and Sons, Inc. Greenhouse Gas-Temp Correlation from Ice Cores

© 2007, John Wiley and Sons, Inc.Methane Methane currently increasing faster than CO 2 in the atmosphere Methane is 21 times more powerful than CO 2 at trapping heat in atmosphere 19% of total atmospheric warming attributed to methane Methane generated by rotting vegetation, digestion in cattle and termites, burning of vegetation, landfills, and melting permafrost

© 2007, John Wiley and Sons, Inc. Nitrous Oxide Depletor of stratospheric ozone 310 times better than CO 2 at trapping heat in atmosphere Produced by combustion of fossil fuels and biomass, use of nitrogenous fertilizers, and decomposition of organic material

© 2007, John Wiley and Sons, Inc. Volcanic Eruptions Sulfur dioxide reacts with water vapor causing haze Combined with ejected particulate matter One of the coldest years in the last two centuries was 1816, the “Year Without a Summer” Caused by eruption of Tambora in 1815 Temperatures can decrease after eruptions for up to 3 years Mount St. Helens

© 2007, John Wiley and Sons, Inc. Variations in Solar Output Climate models predict that a change in solar output of only 1 percent per century alters the Earth’s average temperature by ° C Sunspots Huge magnetic storms Seen as dark (cooler) areas on the sun's surface. Cycle every 11, 90, and 180 years

© 2007, John Wiley and Sons, Inc. Sea Level Issues During this century, global warming will cause sea levels to rise at least 1.5 meters (about 4.5 feet).

© 2007, John Wiley and Sons, Inc. Sea Level Rise During the 20 th century, sea level rose 4-8 inches Could rise inches this century Thermal expansion of water will increase sea level rise Higher sea levels = destruction of small island nations, river deltas, lowland coastal farming, barrier islands

© 2007, John Wiley and Sons, Inc. Disintegration of Ice Shelves In 2002, Larsen-B ice shelve collapsed in 35 days after existing for 11,000 years Warmer ocean and air temperatures are melting shelves on both sides Clear evidence of changes in Earth’s energy balance

© 2007, John Wiley and Sons, Inc. Antarctic Ice Disintegration Figure 10.32

© 2007, John Wiley and Sons, Inc. Arctic Sea Ice Changes

© 2007, John Wiley and Sons, Inc. Arctic Climates Changes in ocean temperatures could alter global temperatures Arctic region warmed 9°F since 1987 This has led to a freshening of northern oceans Greenland ice melting at 1m/year Permafrost is melting Increased precipitation in Arctic/Antarctic areas

© 2007, John Wiley and Sons, Inc. Future Scenarios IPCC predicts accelerated warming through 2100 Greater warming at higher latitudes Positive climate feedback: In warmer Arctic ice melts→less reflection→ greater warming Warmer Earth → more evaporation → more vapor to trap heat, but also more clouds ??? Rising sea levels, shifting agricultural zones, spread of insect-borne disease, more extreme events such as hurricanes and snowstorms, uneven regional effects

© 2007, John Wiley and Sons, Inc. GCM Predictions Crop patterns and natural plant/animal habitats will shift to maintain preferred temperatures During this century, climate regions could shift miles poleward Soil moisture projected to decrease in midlatitudes Forest cover will undergo major species disturbances Expansion of zones affected by tropical diseases Alpine glaciers

© 2007, John Wiley and Sons, Inc. Past Climate Change Prior to recorded data, use Proxy Data: Palynology - pollen in lake sediments shows veg type - > 15,000 year record Dendrochronology - tree rings show growth patterns – 9000-yr record Ice Cores – air trapped over 650K yrs shows past CO 2 concentrations

© 2007, John Wiley and Sons, Inc. Proxy Data Measures cause and effect relationships indirectly Paleoclimatology – science that studies past climates using proxy data Proxy data – ice cores, sediments, coral reefs, ancient pollen, tree-rings Antarctic ice cores have climate reconstructed back 740,000 years Air bubble in ice allow the reconstruction of atmospheric methane levels

© 2007, John Wiley and Sons, Inc. Tree-Ring Records

© 2007, John Wiley and Sons, Inc. Tree-Ring Records

© 2007, John Wiley and Sons, Inc.Palynology

Ocean Core Records

© 2007, John Wiley and Sons, Inc. Solar Energy - pros Figure FS Sunlight represents an inexhaustible supply of energy Insolation receipt in 35 minutes at US surface exceeds energy from burning fossil fuels in a year

© 2007, John Wiley and Sons, Inc. Solar Energy - cons Spatial commitment Structures aren’t wired to receive solar energy Storage for cloudy days

© 2007, John Wiley and Sons, Inc. Coal Energy Zero-emission coal-fired plants?

© 2007, John Wiley and Sons, Inc. Coal Energy - pros One trillion tons of recoverable coal in the world, by far the largest reserve of fossil fuel left on the planet The United States has over 25% of the world’s recoverable coal reserves Figure quoted by the coal industry is 250 years of reserves

© 2007, John Wiley and Sons, Inc. Coal Energy - cons Coal liquefaction expensive uses lots of water produces double the carbon dioxide when compared to regular petroleum use produces diesel when the vast majority of the U.S. car fleet runs on gasoline Ravaged mountains, air pollution from acidic and toxic emissions and fouled water supplies Coal mining is massively more invasive than oil or gas drilling

© 2007, John Wiley and Sons, Inc. Coal Energy - cons Coal burning power plants account for more than two-thirds of sulfur dioxide 22% of nitrogen oxides nearly 40% of carbon dioxide and a third of all mercury emissions in the United States Each year coal plants produce about 130 million tons of solid waste, about three times more than all the municipal garbage in the U.S. The American Lung Association calculates that around 24,000 people a year die prematurely from the effects of coal fired power plant pollution.

© 2007, John Wiley and Sons, Inc. Solution? Carbon Sequestration The Intergovernmental Panel on Climate Change (IPCC) estimated in 2005 that it is highly likely that geologic locations worldwide are capable of sequestering at least two trillion metric tons of CO2 - more than is likely to be produced by fossil fuel consuming power plants this centuryIPCC

© 2007, John Wiley and Sons, Inc. Carbon Sequestration - cons Main risks are sudden escape and gradual leakage of carbon dioxide. Would likely cause soil and water pollution, destruction of terrestrial ecosystems, crops, and soil microbes Acidification of oceans In 1986 at Lake Nyos in Cameroon, Africa carbon dioxide originating from a volcano killed over 1,700 people IPCC estimated in 2005 that in excess of 99% of carbon sequestered is “very likely” to remain in place for at least one hundred years.

© 2007, John Wiley and Sons, Inc. Expensive – would increase electricity costs by 50% Another problem is that it often takes energy to run carbon-sequestering devices, meaning you may end up producing more CO2 in order to capture it. Carbon Sequestration - cons

© 2007, John Wiley and Sons, Inc. The process of nuclear fission allows for the production of tremendous amounts of energy from a small amount of fuel. The cost of making nuclear power is about the same as coal, which is considered very inexpensive Nuclear power does not produce any air pollution or release carbon dioxide and sulfur dioxide into the atmosphere. Therefore, it does not contribute to global warming or acid rain Nuclear Energy - pros

© 2007, John Wiley and Sons, Inc.  Waste produced from nuclear fission of uranium is poisonous, and highly radioactive, requiring maintenance and monitoring at the storage sites.  Need reliable water source.  The Chernobyl accident in the Ukraine (former USSR), where large areas of land were affected by nuclear fallout. Nuclear Energy - cons

© 2007, John Wiley and Sons, Inc. Corn Ethanol - pros Ethanol is an alcohol-based alternative fuel produced by fermenting and distilling starch crops that have been converted into simple sugars. Can make fuel out of crops, sawdust, leaves, algae, and other plants

© 2007, John Wiley and Sons, Inc. Corn Ethanol - cons Expensive Produces as must carbon dioxide to produce it as it replaces when burned Increases in farm pollution Cannot grow enough to replace fossil fuels Increase in food prices 30% fewer miles to the gallon than gasoline

© 2007, John Wiley and Sons, Inc. Ethanol 1 acre of corn = 300 gallons ethanol/year 1 acre soybeans = 60 gallons ethanol/year 1 acre algae = 5000 gallons ethanol/year Algae can be harvested daily

© 2007, John Wiley and Sons, Inc.  Wind power produces no water or air pollution that can contaminate the environment, because there are no chemical processes involved in wind power generation. Hence, there are no waste by-products, such as carbon dioxide.  Wind generation is a renewable source of energy, which means that we will never run out of it. Wind Energy - pros

© 2007, John Wiley and Sons, Inc. Wind Energy - cons Wind is unreliable Storage? Wind farms are ugly Bats Ground-nesting birds Expensive - $10,000 per turbine Mining