#1 Global Warming and Carbon Sequestration Renewable Energy #1 Global Warming and Carbon Sequestration

Global Warming What is it? Is it real? Should I be concerned? How does it apply to a Sustainable Energy class?

What is it? Rise in Earth’s temperature According to the National Academy of Sciences, the Earth's surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades.

What causes it? Attributable to human activities since industrial revolution. Most warming in past 50 years from human activities. Build up of gases like carbon dioxide, water, methane, nitrous oxide and others.

Carbon Dioxide Released to the atmosphere when solid waste, fossil fuels (oil, natural gas, and coal), and wood and wood products are burned. Up 30% since industrial revolution

Methane Emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from the decomposition of organic wastes in municipal solid waste landfills, and the raising of livestock. Doubled since industrial revolution

Nitrous Oxide It is emitted during agricultural and industrial activities, as well as during combustion of solid waste and fossil fuels. Increase 15% since industrial revolution

Other gasses Very powerful greenhouse gases that are not naturally occurring include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), which are generated in a variety of industrial processes.

Video Segment Draw picture of greenhouse diagram (located in supplemental pix at end of PPT) Solar radiation passes through the clear atmosphere. Most radiation is absorbed by the earth’s surface and warms it. Some solar radiation is reflected by the earth and the atmosphere. Some of the IR 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.

What are the results? Rising global temperatures Increased temp may spawn more hurricanes due to warmer oceans More frequent and intense storms with increased evaporation Melting polar caps  rising oceans

Global mean surface temperatures have increased 0. 5-1 Global mean surface temperatures have increased 0.5-1.0°F since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century. Of these, 1998 was the warmest year on record. The snow cover in the Northern Hemisphere and floating ice in the Arctic Ocean have decreased. Globally, sea level has risen 4-8 inches over the past century. Worldwide precipitation over land has increased by about one percent. The frequency of extreme rainfall events has increased throughout much of the United States.

Intergovernmental Panel on Climate Change International group of quasi scientists who blame the U.S. for most of the problem. (Kyoto meetings 1997) IPCC projects further global warming of 2.2-10°F (1.4-5.8°C) by the year 2100. The IPCC states that even the low end of this warming projection "would probably be greater than any seen in the last 10,000 years, but the actual annual to decadal changes would include considerable natural variability."

Emission Inventories –   the chemical or physical identity of the pollutants included, –   the geographic area covered, –   the institutional entities covered, –   the time period over which emissions are estimated, and –   the types of activities that cause emissions. An attempt to decide who, what, when, where, how much and who is to blame for emissions

Carbon Sinks A sink is a reservoir that uptakes a chemical element or compound from another part of its cycle. For example, soil and trees tend to act as natural sinks for carbon – each year hundreds of billions of tons of carbon in the form of CO2 are absorbed by oceans, soils, and trees.

Carbon sequestration Removal of CO2 from the atmosphere by tying it up in long term organic or inorganic recipients. Permanent soil cover Conservation tillage Forestry incentive programs

Carbon soil sequestration not long term solution Carbon soil sequestration not long term solution. It will just “buy us time”. Very difficult to measure effectiveness due to spatial variability. No one knows for sure whether it will work.

Global Carbon Equation Atmospheric CO2 = Fossil Fuel Combustion + Land Use Change (deforestation) - Ocean Uptake - Missing Sink (not certain where it goes)

Is this all hog wash? Some think so! May be normal climatic fluctuation. We’ve had ice ages and hot times but nobody was around with instrumentation.

ØSatellite data indicate a slight cooling in the climate in the last 18 years. These satellites use advanced technology and are not subject to the "heat island" effect around major cities that alters ground-based thermometers. Ø98% of total global greenhouse gas emissions are natural (mostly water vapor); only 2% are from man-made sources.

ØBy most accounts, man-made emissions have had no more than a minuscule impact on the climate. Although the climate has warmed slightly in the last 100 years, 70% percent of that warming occurred prior to 1940, before the upsurge in greenhouse gas emissions from industrial processes. (Dr. Robert C. Balling, Arizona State University)

ØA Gallup survey indicated that only 17% of the members of the American Meteorological Society and the American Geophysical Society thought the warming of the 20th century was the result of an increase in greenhouse gas emissions.

ØLarger quantities of CO2 in the atmosphere and warmer climates would likely lead to an increase in vegetation. During warm periods in history vegetation flourished, at one point allowing the Vikings to farm in now frozen Greenland.

What’s the tie to this class? Green energy is friendlier What is green energy? Government incentives for wind, solar etc. Fuel shortages???

END This material is based upon work supported by the National Science Foundation under award DUE-0434405