It’s Gettin’ Hot in Here!

Key Points Greenhouse Gases-Review Global Warming CO2 Trends Impacts of Greenhouse Gases Reducing Greenhouse Gases Global Cooling The Carbon Cycle

Greenhouses Gases Review Carbon Dioxide- Man-made: burning of fossil fuels and deforestation Natural: respiration and decomposition http://ecosystems.wcp.muohio.edu/studentresearch/climatechange03/deforestation/carbontreeSm.mov Methane Man-made: agriculture, livestock and polar ice melting Natural: swamps and animal digestion Tropospheric Ozone (not the ozone layer) Man-made: Chemical reaction with N2O, VOC’s and Ultra violet light (from burning of fossil fuels) Natural: tiny amounts released by plants and soil

Greenhouse Gases Review Water Vapor Caused by increased evaporation as temperatures rise Nitrous Oxide Man-made: synthetic fertilizers, transportation, industry (nitric acid production) Natural: bacteria in soils, the ocean Hydroflourocarbons Man-made: created to replace CFC’s, found in refrigerants, aerosols, fire extinguishers No natural source of hydrocarbons

GLOBAL WARMING What is global warming? An increase in average global temperature Carbon Dioxide: Can stay in the atmosphere for more than 100 years. Air contains 30% more CO2 than in 1700’s Levels rising about .4% per year

Carbon Dioxide Trends Carbon Dioxide Levels have been increasing steadily over the past 45 years Over past 400,000 years: As CO2 increases, temperature increases and as CO2 decreases , temperature decreases. What kind of relationship is this?

Impacts of Increasing Greenhouse Gases in the Atmosphere Earth’s temperature will rise Human health can be affected. Good effects Bad effects Sea level will rise Shores lines will erode Flooding of the shores Harm living things (other than humans)

Reducing Greenhouse Gases Recycle Decrease use of electricity Alternative energy sources Automobiles-use less often, carpool, fuel efficient, walk when possible, ride bikes when possible, electric cars. Decrease deforestation What else can we do?

Climate Change is not just about warming the climate! Cooling the climate is also called climate change What events can change the climate and make it cooler?

Natural Ways of Changing Climate and making it COOLER GLOBAL COOLING Volcanic Eruptions Meteorite Impacts Changes in how much sunlight reaches the Earth

The Carbon Cycle All living things are made of carbon. When carbon is in the atmosphere, it is attached to oxygen as CO2. Plants use CO2 and sunlight to make food, and the carbon becomes part of the plant. Plants either get eaten and the carbon transfers to the new organism, or they die and can become fossil fuels over millions of years.

The Carbon Cycle When humans burn fossil fuels, they become CO2 back up in the atmosphere again. Excess CO2 gets absorbed by the ocean. This can negatively impact the ocean ecosystem if too much CO2 is absorbed. When humans cut down trees (deforestation), they are no longer able to absorb CO2 from the atmosphere.