Energy to Power the World: I What is Energy Photosynthesis Fossil Fuels

2 Energy is the ability to do work  Kinetic Energy  Energy contained in moving objects  Examples include your notebook falling down the stairs, your brother falling off the couch, water over a waterfall  Potential Energy  Stored energy  Two types: Physical and Chemical  Physical: examples include your brother teetering on the edge of the couch, water about to go over waterfall  Chemical: Energy stored in chemical bonds. In the foods you eat, gas you burn

3 What you need to know about the Universe  Energy and matter are conserved!  Implications:  matter is recycled on Earth (a carbon atom that was once in a Tyrannosaurus Rex could be in your little pinky)  Energy can change forms (potential to kinetic), but will not magnify or diminish itself  1 st Law of Thermodynamics  Energy is spread around as it is converted from one form to another – get less useful energy out than is put in  2 nd Law of Thermodynamics

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5 What you need to know about Energy on the Earth  The Earth’s energy comes from  The sun  The Earth’s internal and gravitational energy  The Sun’s energy powers  the weather  the ocean waves and currents  most living things  your car!

6 Photosynthesis  Net chemical reaction:  6H 2 O + 6 CO 2 + solar energy  (enabled by chlorophyll) C 6 H 12 O 6 (sugar) +6O 2  Photosynthesis stores solar energy in chemical bonds  Energy can be used immediately for cellular respiration  C 6 H 12 O 6 (sugar) +6O 2  6H 2 O + 6 CO 2 + released energy  Energy can be stored for millions of years in organic deposits (fossil fuels)

7 Geologic storage of energy captured by autotrophs  Requirements:  Highly productive ecosystems  Organic matter cut off from oxygen  Geologic processes concentrate energy content  Geologic processes bring to within reach of Earth’s surface

8 Fossil Fuels  Coal  Oil  Natural Gas

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11 Peat deposit in Ireland Rich black indicates high organic content

12 Peat bog in US

13 Increasing depth of burial decreases moisture content and improves quality of coal

14 increasing amount of fixed carbon Decreasing moisture

15 The Earth 350 Million Years ago Coal forming regions

16 Plant Fossils of West Virginia Web site: Vegetation 300 million years ago

17 US Coal Deposits Note: Few high quality (anthracite) deposits

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19 Mountain top removal CS 19.8

20 Similar to CS Fig Would last ~200 yrs at current rates

21 More evenly distributed than oil!

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