2. What is Climate Change?
‘‘It is a change which is attributed directly or
indirectly to human activity that alters the
composition of the global atmosphere and which is in
addition to natural climate variability observed over
comparative time periods”
3. GREENHOUSE GASES
such as carbon dioxide (CO2) absorb heat
(infrared radiation) emitted from Earth’s surface.
Increases in the atmospheric concentrations of these
gases cause Earth to warm by trapping more of this heat.
4. Human activities—especially the burning of
fossil fuels since the start of the Industrial
Revolution—have increased atmospheric CO2
concentrations by about 40%, with more than
half the increase occurring since 1970.
Since 1900, the global average surface
temperature has increased by about 0.8 °C
(1.4 °F). This has been accompanied by
warming of the ocean, a rise in sea level, a
strong decline in Arctic sea ice, and many
other associated climate effects.
5. CAUSES
NATURAL CAUSES
Volcanic Eruptions.
Emissions of methane from animal wastes, a
greenhouse gas.
Earth naturally has a cycle of climate change that
occurs every 40, 000 years.
the sun’s solar energy output is changing and
naturally increases Earth’s average temperature by
about 1ºC every century.
Earth’s orbit and tilt alter in relation to the sun,
which changes solar energy output.
7. EFFECTS
Rise in Sea level.
Heavy Rainfall.
Extreme Drought.
Decline in Crop Productivity.
Ecosystems are changing.
Rise in Temperature.
Carbon dioxide acidifies sea water.
Damaged crops due to sudden climate change and
floods.
Longer summers can disrupt animal habitation.
Increased number of heat-related illnesses and
deaths.
8. DEALING
with G lo b al C limate C hange
To avoid the worst of climate change, CO2 levels must be
stabilized at 550ppm
50% higher than current levels
-Two ways to attempt to manage climate change
Mitigation
Focuses on limiting greenhouse gas emissions to
moderate global climate change
Adaptation
Focuses on learning to live with to the
environmental changes and societal consequences
brought about by global climate change
9. Mitigation
Locate/invent alternative fuels to
fossil fuels.
Increase efficiency of cars and trucks.
Sequestering carbon before it is
emitted.
Plant and Maintain trees to naturally
sequester carbon.
10. Adaptation
Rising sea levels and coastal populations:
-Move inland
-Construct dikes and levees
Adapt to shifting agricultural zones