Long-Term and Short-Term Changes in Climate

1. Long-Term and Short-Term Changes in Climate

2. The Earth is 4.54 billion years old • In it’s history, there have been many natural variations to it’s climate • These change have occurred due to changes in how energy is absorbed and trapped by the Earth

4. For example… • Ice Ages • a period in Earth’s history where the Earth is colder and much of the planet is covered in ice

5. Long-Term Changes are due to: Continental Drift • According to plate tectonics, all of the continents have been moving and are continuing to shift their position on the Earth’s surface • How it impacts climate? • Changes ocean currents and wind patterns • Changes how land masses are distributed which reduces the effect of local bodies of water on climate • Creates mountains which affect climate

6. Video

8. Cycles in Climate • Long term cycles (over tens and hundreds of thousands of years) occur alternating between ice ages and warmer interglacial periods • Theories on why the climate changes: • Shape of the orbit changes over time • Earth’s tilt changes and wobbles

9. Short-Term Changes are caused by: Volcanic Eruptions • When an eruption occurs, rocks, dust and gas are shot high into the atmosphere • These particles reflect the suns rays and lower the energy transmitted to the Earth

10. Changing Ocean Currents • El Nino – a recurring change in the Pacific winds and ocean currents that brings warm, moist air and water toward South America instead of Africa

11. Changes in the Sun’s Radiation • If the amount of radiation from the Sun drops, the Earth receives less energy and cools • Scientist’s are constantly monitoring the Sun’s energy output

12. Homework • Pg 353 # 2, 4, 5, 7