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Climate change and global warming
Aiming Wu
Department of Earth and Ocean SciencesUniversity of British Columbia
Vancouver, BC, CanadaDecember 2004
• What is climate and climate change?
• What is global warming and its effects?
• Why the earth is getting warmer?
• What climate will be in the future?
• What shall we do to protect our Earth?
Outline
Weather: what is happening outdoors in a given place at a given time. Weather changes from minute to minute, and place to place.
• Temperature • Precipitation • Wind • Humidity • Visibility
How to describe weather?
Weather forecast
• TV, radio
• newspaper
(cold, cool, warm, hot)(rainy, snowy, sunny)(light, strong)
(dry or wet)
(fogy, dusty)
• 2 hours later• this evening
• tomorrow ……
Climate: An average of all weather occurring over a period of time in a given place
* Monthly, seasonal (or annual) mean temperature or precipitation (don’t look at the weather on a specific day)
* tells us what it's generally or usually like
* May talks about 10 millions years ago, 10 years ago, this season, this year, next year or 100 years later ……
* Climate also depends on time and place
Victoria, Canada summer 21oC winter 8oC
annual precipitation 1250cm
Sahara, Africa Max. summer 58oC annual precipitation
76mm
mild Dry, hot
Global warming
G * Global mean surface temperatures have increased about 1oF since the late 1800s
* The Earth is getting warmer !
Human Health• Extreme hot weather can directly cause death (over 40oC) [normal human body temperature ?]
• Several serious diseases only appear in warm areas [virus or bacteria like warm place to live]
• Warm temperatures can increase air and water pollution
Severe drought or flood
• more water evaporates, soil will become drier; desert will expand; lake or river levels will drop or even get dried,
• flood in some other places
Sea level rise
• Seas, oceans expand
• Antarctic, Greenland ice melt
• low-lying coastal lands drown
(many people lose their homes)
• large area of farmland be ruined
Farming
• Some plants and crop cannot grow under higher temperatures
• Drought makes plants & crop die (need water)
• people have no enough food, die because of starvation
Animal, forest-fire
• Some animal will die when the temperature changes
• More and more forest fires
Earth
Atmosphere
Other includes:
Argon (Ar, 0.9%)
Water vapor (H2O)
Carbon Dioxide (CO2, 0.03% )
Ozone (O3), CFCs
Methane (CH4)
Also called “greenhouse gas”
Greenhouse gases
* let the sun rays come in
* absorb infrared radiation and emit it back to the Earth
Make the earth warmer
What is in the future ?
It is estimated that CO2 will double from pre-industrial levels in 50-100 years ……
Global temperature
Sea level
By 2050: 0.6-2.5ºC
By 2100: 1.4-5.8ºC
By 2050: 5-30 cm
By 2100: 10-90 cm
What can we do to protect our Earth ?
• Read and learn about the environment science• Save energy (turn off lights, TV, computer…)
• Use bike, bus, walk or car pool
• Plant trees (plants absorb CO2, vapor …)
• Recycle (papers, cans, plastic bags, bottles)
• Use solar energy
• Talking to your family and friends (let them know)
Summary
• The global climate is getting warmer since the late 1800s
• The global warming is making our environment worse and threatening out lives
• Global warming is mainly caused by human activities (industry, transportations etc)
• However, everyone can do something to protect our Earth