The document discusses the composition of Earth's atmosphere and its historical changes, emphasizing the impact of both natural phenomena and human activities on climate change. It highlights the greenhouse effect, increasing CO2 levels since the 1950s, and predicts severe weather patterns and ecological disruptions as a result of global warming. Solutions to mitigate climate change include reducing greenhouse gas emissions, reforestation, and adopting new technologies.

1. Climate Change
Standard: 7.2E.2 Describe the composition of
Earth’s atmosphere, how it has changed over
time, and implications for the future.

2. Tectonic plate motion has
contributed to long-term
climate change over billions
of years. (Still Moving)
Our continents once fit
together as a single
landmass called Pangaea.
What are some natural causes of
climate change?

3. Pangaea began to break up
about 200 million years ago.
Some continents grew warmer
as they moved closer to the
equator, while others moved
to cooler areas like
Antarctica.
Pangaea movement

4. Particles in the Atmosphere (dust) that
reflect sun’s energy back to space and
lower temperature of earth temporarily.
● Asteroid impacts send up large amounts.
○ K-T Boundary asteroid in Mexico 65 million
years ago. (No more Dinos)
● Volcanic eruptions send up ash.
○ Super-volcanoes have caused global
extinction events.
Other natural causes of climate
change

5. Weather changes frequently. Patterns in
weather are the result of changes in the
way energy is distributed around Earth.
This includes:
● Sun Cycles
● El Nino or La Nina
● Ice Ages
Repeating patterns of climate
change

6. Repeating pattern of climate
change.
Sunspot cycle last 11 years.
Minor effect on Earth’s
temperatures.
Sun Cycles
Extreme Ultra-violet Image

7. During El Nino years, ocean
temperatures are higher than usual.
● Causes global weather patterns
La Nina years create cooler than
normal ocean temperatures.
Conditions usual alternate and can lead to
droughts and flooding.
El Nino and La Nina

8. An ice age is a long period of
cooling during which ice sheets
spread beyond the polar regions.
Geologic evidence indicates ice
ages occurring every 200 million
years.
Ice Ages
Last one peaked 20,000 years ago

9. The greenhouse effect is the
process by which gases in the
atmosphere absorb and reflect
heat back to Earth.
● Without this, Earth would be cooler
● Humans Burn Fossil Fuels
● Humans Deforest (cut down trees)
How do humans affect climate
change?

10. Since 1950’s scientists have
measured increasing levels of CO2.
During this same period, average
global surface temperature has
also been rising.
Burning Fossil Fuels

11. A carbon sink removes carbon
from the atmosphere.
Deforestation is the mass
removal of trees for farming,
timber, and land development.
Loss of trees represents a loss of
an important carbon sink.
Deforestation

12. Global Warming is a gradual increase
in average global temperatures.
● effects the Atmosphere
● effects the Hydrosphere
and Cryosphere
● effects the Biosphere
What are some predictable
effects of climate change?

13. Scientist predict that Global
Warming will generate more sever
weather.
● Bigger and Badder Storms
As much as half of Earth’s surface
may be affected by drought.
Effects on the Atmosphere

14. Ice is melting due to increased
temperatures.
● Global sea levels rise
● Increased flooding
● Loss of habitat
Effects on the Hydrosphere and
Cryosphere

15. Scientist predict that Global
Warming will change ecosystems.
● Threaten survival of plants
and animals. (some may
benefit)
● Effect crops and livestock
Effects on the Biosphere

16. Data is collected and
compared over long term.
(since late 1800’s)
Look at rates of change
(speed)
How do we make climate
predictions?

17. ❏ Reduce Greenhouse Gas Emissions
❏ Reduce the Rate of Deforestation
❏ Use New Technologies
How can people reduce their
impact on climate change?

18. In 1997 the Kyoto Protocol was adopted.
● International treaty to reduce CO2 emissions.
● 191 Countries have signed it.
Individuals can help by:
● Conserving energy.
● Increasing efficiency
● Reducing use of fossil fuels
Reduce Greenhouse gas
Emissions

19. Deforestation contributes up
to 20% of greenhouse gases
globally.
Planting trees and supporting
reforestation programs are
ways to increase carbon sinks.
Reduce the Rate of Deforestation

20. Energy-efficient practices
● homes
● businesses
● industry
● transportation
Use New Technologies