Global Geographical issues

GLOBAL CIRCULATION

• Atmosphere transferes heat around the earth - Global Circulation
• High rainfall - Low pressure
• Arid areas - High pressure

• Earth gets energy from the sun
• Enormous circle of air - Circulation Cell
• Hot air rises, then cools and sinks
• Warm air rises - Low pressure

Ocean Currents

• Transferes heat around the globe

• Powered by:

              * Wind from circulation cells

              * Density differences from water temperatures

NATURAL CLIMATE CHANGE

Natural Causes

• Earths orbit changes once every 100000 years - Milankovitch Cycles
• Energy radiated from sun changes over an 11 year cycle
• Volcano erruptions pump ash - Causing a cooling effect
• Large asteriod collisions - Causes cooling as it blocks out sun
• Ocean current changes - Causes cooling & warming