9.4- Natural causes of climate change

Climate change is NOT new; it’s happened many times before Note: None of natural causes of climate change accounts for the recent trend in global warming

1. Long term changes Which continents appears to have fitted together in the past?

Over time, the positions of the continents have changed, affecting Earth’s climate Impacts of moving landmass on Earth’s climate: -Ocean current and wind currents change which affect heat transfer around Earth -Causes mountain ranges to rise up, which also affects local and regional climates

2. Short term changes a. Volcanoes: Volcano eruption Releases dust, gas high into the atmosph ere Reflect Sun’s energy back into space Cool Earth’s surface

Short term changes b. El Nino: -Every 3-7 years -Caused by interactions between trade winds and the ocean -During El Nino: Prevailing winds over the Pacific ocean reverse direction causing ocean current to also reverse direction, pushing the warm surface water toward the east Pacific (instead of the west)

Impacts of El Nino drought in Australia, New Guinea, India, and Africa Flood in South America mild winters in Canada severe winters in California, All of this is signaled by a rise in sea surface height of 18 cm (7 inches)!

Practice questions ( Answers on next slid e) 1.How does the movement of Earth’s land masses affect climate? 2. How do volcanic eruptions affect climate? 3. What is an El Nino? 4. The long term natural cause of climate change is: 5. The short term natural causes of climate change are:

Practice questions 1.How does the movement of Earth’s land masses affect climate? __Their location changes, ocean currents and wind patterns change, the distribution of land masses change, mountain ranges can be created._ 2. How do volcanic eruptions affect climate? _Dust and gas are released into the atmosphere which reflect the sun’s energy 3. What is an El Nino? _A change in the Pacific winds and ocean currents that brings warm, moist air to the west coast of South America 4. The long term natural cause of climate change is: __Position of the Earth’s land masses.___ 5. The short term natural causes of climate change are: _Volcanoes, El Nino______________________