THE CARBON CYCLE AND GLOBAL WARMING

CARBON 4TH most abundant element on Earth Essential for life- all organic (living) compounds are composed of carbon Found in various forms: Carbon dioxide (gas) Limestone (solid) Wood Plastic Diamonds Graphite Fossil fuels

CARBON CYCLE Movement of carbon between the atmosphere, oceans, biosphere, and geosphere Divided into two components: Geological carbon cycle Biological carbon cycle

GEOLOGICAL CARBON CYCLE Carbonic acid combines with minerals on the earth’s surface forming carbonates (weathering) Carbonates erode from the surface into the ocean and settle on the ocean floor Sinks into the earth, heats up, and eventually rises up as carbon dioxide into the atmosphere * OCCURS OVER MILLIONS OF YEARS

GEOLOGICAL CARBON CYCLE Carbon dioxide diffuses into the ocean forming bicarbonates or calcium carbonate (used to make shells and other body parts by organisms such as coral and brachiopod shells) These organisms die and their shells and body parts become carbonate-rich deposits After a long period of time, these deposits become sedimentary rocks, coal, or oil

BIOLOGICAL CARBON CYCLE The movement of carbon through the processes of photosynthesis and cellular respiration Also, the consumption of living matter by other organisms The amount of carbon cycled through annually is a 1,000 times greater than the geological carbon cycle component

6CO2 + 6H2O + light energy → C6H12O6 + 6 O2 PHOTOSYNTHESIS Autotrophs take in carbon dioxide, water, and sunlight to produce sugars and oxygen Chemical Formula: 6CO2 + 6H2O + light energy → C6H12O6 + 6 O2

CELLULAR RESPIRATION C6H12O6 + 6O2 → 6CO2 + 6H2O + energy Carbon dioxide is released back into the atmosphere by breaking down sugar during cellular respiration Chemical Formula: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

RELEASE OF CARBON DIOXIDE CO2 is also released into the atmosphere by: Decaying dead matter Forest fires Volcanoes Burning of fossil fuels (coal, oil, gas)

HUMAN IMPACT Since the onset of the industrial revolution, burning of fossil fuels and deforestation have lead to increase of atmospheric CO2 There is strong evidence that supports the idea that these activities increase the atmosphere’s ability to hold in heat (greenhouse effect) and is resulting in a climate change (global warming)

GREENHOUSE EFFECT Greenhouse effect: process by which carbon dioxide and other gases in the atmosphere absorb infrared radiation from the sun, forming a “heat blanket” around the Earth Some sunlight is reflected and other is trapped as heat to warm the Earth Enhanced greenhouse effect: caused from an increase of carbon dioxide, methane, and nitrous oxides from human activities into the air which traps more heat and raises the temperatures of the Earth’s surface

CLIMATE CHANGE Global Warming: an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns A rise in sea level A wide range of impacts on plants, wildlife, and humans When most scientists talk about the issue of climate change, their concern is about global warming caused by human activities.

GLOBAL WARMING DEBATE POSITION 1 Human pollution is the cause Carbon dioxide released into the atmosphere has increased by 30% in the last 200 years Over the last 100 years, temperatures have increased slowly due to an increase in greenhouse gases (CFC’s, nitrous oxides, methane, and carbon dioxide) POSITION 2 Natural patterns and fluctuations Nothing to do with human activities Carbon dioxide usage is hard to measure (ex. plant absorption) Temperatures have increased and decreased in the past

READ AND RESPOND Even with a dramatic cut in global greenhouse emmisions, most scientists predict a temperature rice of about 2C (4.4F) over the next century. Think about your daily routines, how would your life be different if it were two degrees warmer? Think about the foods and products that you consume throughout the year, how would a 2 degree increase affect their availability? Think about the community in which you live, how would a 2 degree increase in the average global temperatures affect jobs, businesses, and industry in your community?