WEATHER or CLIMATE? Can you tell the difference? Put these words in to two lists under the headings ‘Weather words’ and ‘Climate words’ Cold winters Cloud cover Wet summers Temperature Wind direction dewpoint C W C W W W C W C W W W

 What is weather ? › Atmospheric conditions in a particular location over a short period of time  What is climate ? › The average weather in a region over a long period of time › The Earth’s climate has changed dramatically over the Earth’s history

 EVERYONE!!

 Climate Zone: areas on Earth with similar climates  What are some areas on Earth that have similar climate?

 Can you think of some factors that cause different climates in different areas???  Climate is caused by: › 1. Latitude (distance from the equator) › 2. the presence of large bodies of water › 3. The presence of ocean or air currents › 4. Land formations › 5. Altitude (height above see level)

 Climate System: the complex set of components that interact with each other to produce Earth’s climate  What do you think these components are? › Air, Land, Liquid Water, Ice, Living things  What powers this system?  The Sun!  The interaction of these components and the sun produce climate zones!

 Almost all energy on Earth comes from the sun, in the form of UV radiation, visible light and infrared radiation  30% of sun’s energy is reflected  70% of it is absorbed (by surface, clouds or atmosphere)

 If Earth’s absorbs 70% of the sun’s energy how come it isn’t just getting hotter and hotter??  The sun’s energy can be converted from one form to another  Earth absorbs different wavelengths from the sun, heats up and gains thermal energy  It then emits this as infrared radiation which returns to the atmosphere and back into space  energy absorbed = energy radiated  so Earth’s global temperature stays constant

 How does latitude affect Climate?  Climate is warmer closer to the equator  Why? › More direct sunlight (less spread out) › Less atmosphere to pass through (because less spread out)

 Atmosphere : the layers of gases surrounding the earth  78% nitrogen  21% oxygen  1% argon, CO2, helium, hydrogen, ozone  Reflects, absorbs and radiates, or transmits energy  Acts as a blanket – conserving thermal energy to keep Earth warm  Also shields earth from dangerous radiation

 In the stratosphere (50km up), ozone absorbs dangerous UV radiation  protects us!  Human made chlorofluorocarbons (CFCs) thins the ozone (less protection!)  CFCs were in spray cans, refrigerators and AC and were banned in 1987  The ozone has slowly been recovering

 Ozone in the troposphere (6-20km) is toxic and corrosive  Created from car exhausts reacting in UV radiation  Produces smog – harmful to human health, damages buildings and affects plans and animals  Drive clean introduced to help reduce it

 Liquid water, water vapour and ice  Reflect, absorb and emit, or tramsits energy from the sun  Water Cycle › Energy is absorbed when water evaporates  cools surroundings › Energy is given off when water vapour condenses into clouds  warms surroundings

 How do these affect climate?  Water absorbs and stores more thermal energy than land  Water heats up and cools down more slowly than land  Regions near oceans or a large lake are cooler during the summer and warmer during the winter  Regions downwind from large bodies of water have more snow

 How does Ice Affect Climate?  2% of Earth’s water is frozen  Most ice is located at the two poles  Sea ice: thin and floats on the ocean  Ice sheets : enormous areas of permanent ice stretching over land  Surfaces covered in ice and snow reflect more radiant energy than land (another reason why the poles are so cold)

 Litosphere : Earth’s Crust  Absorbs high energy radiation from the sun, converts it to thermal energy, and emits it as low energy infrared radiation  How do you think mountains affect climate? › Clouds lose moisture as rain on one side of the mountain and the other side is dry!

 What about the climate on at higher altitudes? › Higher up there’s less pressure which causes air to expand and cool so it’s cold!

 Organisms change the amount of gas in the atmosphere through photosynthesis and cellular respiration  Some animals (cows, sheep, termites and bacteria) produce methane gas  Carbon dioxide and methane absorb infrared radiation  A change in the amount of these gases affects how much radiation is absorbed

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 Read pg  Questions:  Pg. 321 #1, 4, 5  Pg. 329 # 1-6  Pg. 335 #1, 3-5