Variations in Climate

1. Variations in Climate Earth’s energy balance &  climate can change naturally due to:

2. Long-term Changes to Climate • 1. Continental Drift movement of continents changes ocean currents & winds (effects heat transfer) •  areas with more ocean have a more moderate climate • 2. uplifting of new mountains & weathering of old mountains •  effects regional climates

3. 3. Amount of energy produced by the Sun •  changes gradually • 4. Changes in Earth’s orbit  shape of Earth’s orbit, tilt & how much it wobbles all change regularly  the amount of sun received changes •  leads to regular cycles of ice ages and interglacial periods (warmer)

4. Short-term Variations in Climate • 1. Volcanic Eruptions release dust, rocks & gases into atmosphere that shade Earth & cool it • 2. Air & Ocean Currents  changes in ocean currents (thermohaline circulation) can abruptly change climate

5. Ex. El Nino – occurs every 3-7 years • - Pacific winds change direction, changing ocean currents & South America gets warm, wet weather • 3. Changes in the Sun’s radiation •  amount of radiation can fluctuate slightly