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9.4 Climate Change. Global warming or climate change Greenhouse effect Impacts. Weather. Day to day temperatures Changes with the seasons. Climate. Long-term patterns of weather in a region Climate should not change much over the years. Patterns. World has warmed and cooled for years - PowerPoint PPT Presentation
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9.4 Climate Change
Global warming or climate changeGreenhouse effect
Impacts
Weather
• Day to day temperatures• Changes with the seasons
Climate
• Long-term patterns of weather in a region• Climate should not change much over the
years
Patterns
• World has warmed and cooled for years• Several ice ages in the last million years• Scientists can look at ice cores in glaciers to
find out what the climate was like• Or muck at the bottom of lakes• Or rings inside a tree
Last 100 years
• The global temperature is rising• It has increased almost 1 degree C
Climate Change
• Many changes are occurring besides temperature..some places experience….
• More rain• More drought• Colder temperatures• More cloud cover• Natural disasters – flooding, hurricanes
Extreme Weather
• Floods• Hurricanes• Droughts• Damage buildings, kill people, wildlife, destroy
crops
A Few Degrees
• The last ice age the world was only about 4-6 degrees cooler than it is today
• By 2080 winter temperatures in the Arctic could rise up to 14 degrees
• Summer temperatures could increase 4-7 degrees
Our Atmosphere
• The sun’s energy is absorbed by land and water
• Absorbed heat is slowly released into the atmosphere
• The atmosphere traps the heat in, like a greenhouse
Greenhouse Gases
• Green house gases• Carbon dioxide, methane and nitrous oxide
Greenhouse gases
Nitrous oxide
Water
Carbon dioxideMethane
Sulfur hexafluoride
“Greenhouse effect” Increasing greenhouse gases trap more heat
Greenhouse Effect
• The rise in Earth’s average temperature over time
• Due to gases that trap heat• Without these gases, heat would escape back
into space and Earth’s average temperature would be about 60ºF colder.
What do climate scientists really think?
Human Activities
That emitt green house gases• Burning fossil fuels• Fuel for vehicles-gas, diesel• Heat - propane, natural gas• Electricity – coal• Cutting down trees and plants
Impacts
• Crazy weather• Melting permafrost (landslides)• Break up of sea ice (homes for wildlife)• Rising sea levels (flooding of coastal cities)• Forest fires (too dry)• Southern species are moving North
Carbon Sink
• Absorb and store carbon• Forests, soil oceans, plants, animals
Carbon Sequestration
• Store excess carbon emitted by humans• Carbon sinks naturally • Plant trees• Protect forests
Artificial Trees
• Built to absorb carbon