GLY150: INTRODUCTION TO OCEANOGRAPHY

University of North Carolina Wilmington

I. Global Heat

Solar Radiation
- Electromagnetic Spectrum
Distribution of Solar Radiation on Earth's Surface
- Latitudinal variations
- Annual cycles due to tilt of Earth's axis
Heat Budget of the Earth
- Incoming shortwavelength visible radiation
- scattered in atmosphere
- reflected by atmosphere
- absorbed by earth
Outgoing longwavelength infrared radiation
- absorbed by atmosphere
- reradiated into space

II. Global Warming: Fact or Fiction?

Greenhouse Effect
- Greenhouse Gases
  - Water vapor - largest contributor
  - Carbon Dioxide
  - Methane
  - CFCs
Global Temperatures, Past and Present
- Increase of >0.5C over the past 100 years
- Similar warming trends seen in past
Changes in Global CO₂ Concentration
- Anthropogenic
- Deforestation
- Burning fossil fuels
- Natural
- Degassing of Earth's interior by mantle plumes
- Carbon Cycle - respiration and weathering
Other Factors that Change Global Temperature
- Volcanoes - sulfur aresols bring about global cooling
- Change in Earth's orbital parameters (Milankovitch Cycles)
  - Eccentricity
  - Precession
  - Obliquity
Predicted Long-Term Effects of Global Warming
- Melting of polar ice caps, thermal expansion of seawater
- Rise in sea level
- Changes in global precipitation/climate patterns