1. Energy Drives the Earth System
Radioactive decay at core is released into the mantle, fueling volcanos, driving plate movement
(Integrated science C/D year)

2. 30% 20% 50% Energy Drives the Earth System
Solar radiation penetrates the atmosphere, warming oceans & land, converted by plants into organic fuel
30%
20%
50%

3. Only some EMR waves make it to Earth’s surface
Absorbed by Earth
reflected
reflected
The elecromagentic radiation spectrum

4. 50% Energy Drives the Earth System
Although infrared, visible, some UV EMR reach the sea, land, all reradiated EMR is infrared (heat)
50%

5. terrestrial radiation
solar radiation
terrestrial radiation
• shorter wavelength
visible, UV EMR
• absorbed by land, water
• absorbed solar radiation is
re-radiated to atmosphere from
Earth
• longer wavelength
infrared (heat) EMR
infrared

6. In effect, the sun heats the Earth…
…and the Earth heats the air, as terrestrial radiation is absorbed by greenhouse gases
CH4
H20
absorbed solar radiation terrestrial radiation

7. Just like in a greenhouse…
…or in your car

8. Thus, the lower atmosphere acts as a blanket,
keeping the Earth a comfortable temperature

9. Mars • 0.01x of the density of Earth’s atmosphere 96& CO2)
Venus • 90x density of Earth’s atmosphere
96.5% CO2
Both are >95% Co2
462° C (863° F)
Too hot!
-46° C (-51° F)
Too cold!
average surface temperatures

10. Earth’s temperature has changed over time
Warm
Cold
Icy
Not icy
How do they know past climates? Recent – data records
Historic records – further into human history: droughts, floods, etc
Paleoclimates – deduce from ‘proxies’: Ice cores, tree rings, coral growth, sediment deposits (CaCO3)

11. Atmosphere temperature correlates with CO2
Year-by-year atmospheric CO2

12. Fossil fuel use > CO2 byproduct > warming
Temperature
Fossil Fuel use
Lagged means 25 time lag (time for atmospheric build up)

13. Compounding factor: permafrost methane
methane released as soil thaws
from the atmosphere. Methane's lifetime in the atmosphere is much shorter than carbon dioxide (CO2), but CH4 is more efficient at trapping radiation than CO2. Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2
impact of CH4 is 20x that of CO2

14. POGIL: Climate Change
Q 7: Human population connection

15. Trend: a warming planet

16. What’s different about this climate change? anthropogenic source
great rate of change
(and increasing)