The Carbon Cycle and the Greenhouse Effect

CARBON 4th abundant element on the Earth Essential for life (organic compound) Found in many forms: Carbon dioxide limestone (solid) Wood Plastic Diamonds Graphite Fossil fuels

Carbon Cycle Movement of carbon between the atmosphere, lithosphere and hydrosphere Two Divisions: Biological Carbon Cycle 2. Geological Carbon Cycle

Biological Carbon Cycle Photosynthesis and Cellular Respiration! Also decomposers who break down dead matter!

Photosynthesis 6CO2 + 6H2O + Energy → C6H12O6 + 6 O2 Autotrophs take carbon dioxide, water and sunlight and convert them into oxygen and glucose (sugar). Chemical Formula: 6CO2 + 6H2O + Energy → C6H12O6 + 6 O2

CELLULAR RESPIRATION C6H12O6 + 6O2 → 6CO2 + 6H2O + energy Carbon dioxide is released when sugar is decomposed during cellular respiration. Chemical Formula: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

A comparison: Photosynthesis : 6CO2 + 6H20 + energy -> C6H12O6 + 6O2 carbon water from the sun glucose oxygen dioxide Cellular Respiration : 6O2 + C6H12O6 -> 6CO2 + 6H20 + energy oxygen glucose carbon water dioxide These two processes complete the carbon cycle. (the equations are complimentary!!)

Carbon Dioxide CO2 is released in the atmosphere equally by: Decomposition of dead matter Forest Fires Volcanoes Combustion of fossil fuels (coal, oil, gas)

Geological Carbon Cycle Aquatic systems also! In the shells of aquatic animals you can find carbon! When these animals die, they fall to the bottom of the ocean and transform into hard sedimentary rock. After a very long time, this rock can be mined for coal and oil.

Human Impact Since the industrial revolution, the burning of fossil fuels and clear-cutting has increased the CO2 in the atmosphere. There are many proofs that indicate that the earth is warming due to an increase in these greenhouse gasses in the atmosphere (global warming).

Greenhouse Effect Greenhouse Effect: Natural process caused as a result of greenhouse gases trapping some of the sun’s energy that would otherwise leave Earth. Greenhouse gases: CO2, N2, CFCs, CH4 Some of the sun rays are reflected while others are trapped to warm the earth. Human Effects…

Changing Climate Global Warming: an increase in the average temperature of the Earth, which in turn has changed some of our climate. Higher global temperatures can cause: Extreme weather Sea levels rising Can have a huge impact on humans, plants and animals.

Global Warming Debate POSITION 2 POSITION 1 Natural fluctuations. Has nothing to do with human activity. CO2 use is hard to measure. (ex. How much CO2 is absorbed by plants) Temperatures have fluctuated in the past. POSITION 1 Caused by pollution. The amount of carbon dioxide has increased by 30% in the last 200 years. In the last 100 years, the global temperatures have increased because of the increased use of greenhouse gasses. (CFCs, N2, CO2, CH4)

Video – Global Warming 101 Climate Change Nova Scotia

To Do: Read pages 304-305 Vocabulary Words : Greenhouse Gasses Greenhouse effect Look at table 7.3 on page 305. Write down two ways that excess carbon dioxide could affect the sustainability of the atmosphere. Similarly, write down two ways it could affect the sustainability of the oceans. After reading pages 304-305, complete the following questions : (p. 308, #13 and p. 311, #’s 3&4)

Answers to questions from sheet

Video – Global Warming – What you need to know (1 hour and a half) Video – Earth Under Water (45 minutes) Video - PBS Global Warming - The Signs and the Science