Download Anthropogenic Climate Change

Anthropogenic Climate Change
Global Temperature is Increasing
How We Know This
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Measured data
Natural indicators
Observation
Ice
Weather
Wildlife
Natural Forcing
- “Radiative forcing is a
measure of the
influence a factor has in
altering the balance of
incoming and outgoing
energy in the Earthatmosphere system and
is an index of the
importance of the factor
as a potential climate
change mechanism. In
this report radiative
forcing values are for
changes relative to
preindustrial conditions
defined at 1750 and are
expressed in Watts per
square meter (W/m2)” IPCC
Source: IPCC (Intergovernmental Panel on Climate Change)
Source: “High-resolution carbon dioxide concentration record 650,000–800,000 years
before present”
-Compilation of CO2 records and EPICA (European Project for Ice Coring in Antarctica)
Dome C temperature anomaly over the past 800 thousand years
- Changes in past atmospheric carbon dioxide concentrations were determined by
measuring the composition of air trapped in ice cores from Antarctica
-atmospheric carbon dioxide is strongly correlated with Antarctic temperature
throughout eight glacial cycles
Source: United States Global Change Research Program (2009)
Anthropogenic Forcing
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Source: NOAA (National Oceanic and Atmospheric Administration)
Greenhouse Gases
• CO2, N2O, CH4, H2O, CFCs, O3
• Energy absorption
– Larger gases vibrate when struck
– Think about ozone
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CO2 absorbs infrared emitted from Earth’s surface
Bouncing around of energy keeps surface warm
Net positive forcing of 1.6 W/m2
Varying atmospheric lifespan
Source: http://centerforoceansolutions.org/climate/impacts/cumulative-impacts/storm-intensity/
Source: Greenpeace
Source: U.S. Environmental Protection Agency
Source: U.S. Environmental Protection Agency