ANTH 1010 Lecture 3: Gaining a Historic Perpspective on Climate Change Continued
Document Summary
Weather is local and it occurs in a certain point in time. Climate is over a long period of time and also global average temperature. Over the billions of years of earth"s existence, it has changed many times in response to natural causes. Natural causes of climate change : volcanic eruptions, ocean current, the earth"s orbital changes, and solar variations. Volcanic eruptions - when a volcano erupts it throws out large volumes of so2, water vapor and dust into the atmosphere eventually causing atmospheric cooling because it increases planetary reflectivity and sunlight back out of the atmosphere. Tiny particles called aerosols are produced by volcanoes; because they reflect solar energy back into space they have a cooling effect on the world. Ocean current - ocean currents move vast amounts of heat across the planet, pushing wind horizontally against sea surface and drive ocean current patterns.
