Unit 6 (Energy Budget and Insolation) Extension- Climate Change: Long and Short-Term Natural and Un-natural causes
Natural: Long Term Changes Ice Ages
Pleistocene Advance and Retreat pg. 112 figure 6-10
Glacial Retreat and Sea Level
Causes for periodic ice ages 1.) Changes in Earth’s Axial Tilt (A DECREASE in tilt) 2.) Changes in our orbits eccentricity (every 90,000 to 100,000 years)- (here a decrease) 3.)Decrease in sunspot activity (below)-Maunder Minimum resulted in the last “mini-ice age” during the late 1600’s
Every 40,000 tilt changes
Global Cooling-Short Term (could also be long term if prolonged) 4 Global Cooling-Short Term (could also be long term if prolonged) 4.) Major Volcanic Eruptions
Short Term Natural Warming: El Nino-warming of pacific waters
La Nina- Cooling of Pacific Waters Dry conditions in the south + warm Wet conditions in the North + cool!
Natural Global Warming (Long Term) 1.) Plate Tectonics-The continents were not always where they are today
2. ) Changes in Earth’s Tilt (an increase in tilt) 3 2.) Changes in Earth’s Tilt (an increase in tilt) 3.)Changes in orbit- increased eccentricity of Earth’s orbit –results in 20-30% more energy absorbed during perihelion (winter)
Short term warming: Increase in sunspot activity (11 yr. cycle)
Current Climate Change Increased warming due to ↑presence of greenhouse gases
Increased air temperature results in higher frequency and intensity of storms!
Deforestation and Urbanization result in increased temperatures
Deforestationdesertification
Urbanization