global changes in the atmosphere pages 139-142. what is global warming? the gradual increase in the...
TRANSCRIPT
Global Changes in the Global Changes in the AtmosphereAtmospherePages 139-142
What is global warming?What is global warming?The gradual increase in the
temperature of Earth’s atmosphere
Over the last 120 years, the average temperature of the troposphere has increases 0.5 degrees Celsius
What is the greenhouse What is the greenhouse effect?effect?
The process by which gases in Earth’s atmosphere trap solar energy and keep the Earth warm
Greenhouse Gases- water vapor, carbon dioxide & methane
What are some causes of global What are some causes of global warming?warming?Increasing greenhouse gases (especially CO2)
What adds CO2 to the atmosphere?Human activities that add greenhouse gases to
the atmosphere may be warming Earth’s atmosphere
Burning of wood, coal, oil and natural gases
add CO2#1cause- motor vehicles
Another Hypothesis?Another Hypothesis?
Natural climate variations (a natural cycle caused by changes in solar output)
Remember the ice age/interglacial periods?
Possible EffectsPossible Effects
Longer growing seasons in some areas and shorter growing seasons in others
More evaporation drying out soil-> dust bowls
More storms; not just hurricanes, but also winter storms
Rising sea levels due to ice caps melting-> flooding
Ozone DepletionOzone DepletionChemicals produced by humans have
been damaging the ozone layer
Chlorofluorocarbons (CFCs)- complex chlorine compounds found to destroy ozone molecules
Found in air conditioner and refrigerator coolants, some cleaners and spray cans
Impacts of ozone Impacts of ozone depletiondepletionMore UV rays reaching the surface and causing more eye and skin damage
What is being done?What is being done?
In the late 1970’s 196 countries joined the Montreal Protocol agreeing to discontinue the use of CFCs in spray cans.
Figure 21Figure 21
The Scientific Assessment of Ozone Depletion 2010 report said a 1987 international treaty that phased out chlorofluorocarbons (CFC) - substances used in refrigerators, aerosol sprays and some packing foams - had been successful.
