global warming by adam leeper and jennifer fox. global warming a gradual increase of planet-wide...
DESCRIPTION
The Greenhouse Effect A natural effect, due to normal amounts of carbon dioxide and water vapor in the atmosphere. The gases absorb infrared radiation to keep the earth at a suitable temperature for life.TRANSCRIPT
Global Warmingby
Adam Leeper and Jennifer Fox
Global Warming
• A gradual increase of planet-wide temperatures.
• Greenhouse effect: Swedish chemist suggested in 1896 that we were increasing the Earth’s natural greenhouse effect, leading to global warming.
The Greenhouse Effect
• A natural effect, due to normal amounts of carbon dioxide and water vapor in the atmosphere.
• The gases absorb infrared radiation to keep the earth at a suitable temperature for life.
The Greenhouse Gases
• CH4, Methane
• H2O, water vapor
• CO2, Carbon Dioxide
• N2O, Dinitrogen Oxide
Carbon Dioxide, CO2
• Natural Sources: Respiration, decay of organic matter, “natural” forest fires.
• Human Sources: combustion of organic resources such as fossil fuels and wood, for everything from industry to transportation.
• Up 25% since Industrial Revolution.
• Atmospheric life 50-200 years.
Methane, CH4
• Natural Sources: Wetlands and termites.
• Human Sources: cattle farming, rice fields, land fills, coal mining, David’s little brother, petroleum and natural gas processing.
• Up 145% (!) since IR• Life 12 years
Nitrous Oxide, N2O• Natural Sources: “Bacterial Action”• Human Sources: Nitrogen Fertilizers• Up 15% since Industrial Revolution.• Atmospheric life of 120 years.
Water Vapor, H2O• Natural Sources: Evaporation (!)• Human Sources: Combustion of
hydrocarbons.
Recorded Effects
Over the last century:• Average global temperatures have
increased by about ½ degree Centigrade.• There has been a 1% increase in average
precipitation.• Sea levels have risen by about 15-20 cm,
6-8 inches. (The Dutch are even further underwater ;-)
Theoretical Effects:• Health: Life cycles of pathogens and insects
made easier when warm. Disease thrives.• Agriculture: Changed crop yields; some
crops will enjoy the increased temp, others will suffer.
• Forests: Dryness and droughts will make forest fires flare. (No pun intended)
• Water: More extreme conditions, from more flooding to longer droughts.
• Coasts: low-land flooding.• Habitats will change or be destroyed;
species relying on cold/ice will be screwed.
Particulates• Small particles, products from combustion and
heavy industry; volcanoes.
• Counteract greenhouse gases by deflecting sunlight, scattering radiation.
• Provide something for water vapor to condense on, adding cloudiness to reflect radiation and increase precipitation, ultimately cooling the Earth.