Visualizing Environmental Science

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NG Maps

Global

Locator

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The eruption of Mount Pinatubo in the Philippines

in 1991 injected massive amounts of sulfur into the

atmosphere. Because sulfur haze reduces the amount

of sunlight reaching the surface, this eruption caused

Earth to cool temporarily. Compared to temperatures

during the rest of the 1990s, global temperatures in

1992 and 1993 were relatively cool.

2.5

2

1.5

1

0.5

0

• 0.5
  
  
  • 1
  
  
  
  


• 1.5

Radiative forcing (W/m

2 )

Greenhouse

gases

Halocarbons

Tropospheric

Stratospheric

Stratosphericwater vapour

CO

2

CH

4

Ozone

Aerosols

Direct effectReflectionoff aerosols

N:O

CH

4

Intergovernmental Panel on Climate Change (2005). “Safeguarding the Ozone Layerand the Global Climate System: Issues Related to Hydrofluorocarbons andPerfluorocarbons” Figure TS-4.

Interpreting Data

Which factors contribute most to climate

change? What is the total radiative forcing

of all factors on this graph combined?

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Radiative forcing is measured in watts per square

meter (W/m^2 ). Stratospheric ozone and aerosols cause

the atmosphere to retain less energy; the other gases

cause it to retain more. Overall, humans are causing a

net increase of atmospheric radiative forcing.