1. III. BIOGEOCHEMICAL CYCLES
Overview
The Water Cycle
The Carbon Cycle
1. OVERVIEW

2. RESERVOIRS:
Most atmospheric carbon has been transferred to the hydrosphere (dissolved CO2) and lithosphere (limestone and fossil deposits).
Dead and dissolved organic matter are other large reservoirs
The atmosphere and biosphere have some, too.
reservoirs in gigatons and exchanges in GT/year

3. FLUXES:
Flux between hydro and atmo is still a major exchange
reservoirs in gigatons and exchanges in GT/year

4. FLUXES:
Photosynthesis balances respiration
Volcanism balances by sedimentation and deposition
Net transfer to atmosphere is by burning of fossil fuels (7 GT) and reduction of photosynthesis by forests from deforestation (1 GT)
reservoirs in gigatons and exchanges in GT/year

5. - last 160,000 years (ice cores)
401
280

6. - Since 1000: up 43% (all since 1760 – Industrial Revolution)

7. - Since 1955: 318 to (Sept 5, 2016) – 26%

8. - Ocean absorption and acidification

11. III. BIOGEOCHEMICAL CYCLES
Overview
The Water Cycle
The Carbon Cycle
1. OVERVIEW
2. Change in CO2
3. Consequences – Global warming

12. 2. Since 1860 – increase of 0.8oC – ten hottest years all since 1998
2015 – hottest by the greatest margin; 2016 on pace to be hotter
15 of 17 hottest years on record ALL SINCE 2000

13. Most heat is absorbed by ocean

15. III. BIOGEOCHEMICAL CYCLES
Overview
The Water Cycle
The Carbon Cycle
1. OVERVIEW
2. Change in CO2
3. Consequences – Global warming
4. Correlates

16. Reductions in Polar Ice
(area covered)
1979
Nasa.gov
2012

17. Summer 2012 – Record low summer sea ice

21. Reductions in polar ice
Reductions in glacial ice
B-15 is the size of Connecticutt (2000)

22. Reductions in polar ice
Reductions in glacial ice

23. Reductions in polar ice
Reductions in glacial ice
Sea level rise

24. - Increases in Sea Level

25. Reductions in polar ice
Reductions in glacial ice
Sea level rise
Melting of Permafrost
14% of the world’s organic carbon is stored in permafrost. As the poles warm (and they are warming faster than anywhere else), this carbon may be mobilized as decomposing bacteria gear up….
This is a type of threshold response (not a gradual response), and would involve positive feedback loops…

27. - More big storms:

29. Reductions in polar ice
Reductions in glacial ice
Sea level rise
Melting of Permafrost
Stronger Storms
Effects on the Biosphere
- Changes in Plant Growth:
Qualitative Effects:
Laurance et al. (March 2004, Nature):
- Pristine rainforests have changed composition in last 20 years, with an increase in fast-growing species and a decrease in slow growing species… probably as a result of increased CO2 availability.

30. Reductions in polar ice
Reductions in glacial ice
Sea level rise
Melting of Permafrost
Stronger Storms
Effects on the Biosphere
Changes in Reef Communities:
“Almost 15% of the world's reefs are already beyond repair thanks to global warming. Another 30% may be lost over the next 30 years.”
– (Nature, February 2004)
- Reefs are home to 25% of all marine species
- Reefs are nursery areas for the larvae and fry of commercially important fish and crustacean species
- Reefs are important storm breaks for tropical coasts

31. Reductions in polar ice
Reductions in glacial ice
Sea level rise
Melting of Permafrost
Stronger Storms
Effects on the Biosphere
- Changes in Species Diversity
15-37% of terrestrial species may go extinct in the next 50 years, largely because of global warming. (Thomas et al. 2004)

32. Reductions in polar ice
Reductions in glacial ice
Sea level rise
Melting of Permafrost
Stronger Storms
Effects on the Biosphere
Increases in Human Diseases:
UN Environmental Programme Report, Feb 21, 2005:
- Environmental change may be the cause of the resurgence of some infectious diseases.
- The fatal Nipah virus, normally found in Asian fruit bats, is believed to have crossed over to humans as the bats lost their habitats through forest fires in Sumatra and the clearance of land for palm plantations.

33. III. BIOGEOCHEMICAL CYCLES
Overview
The Water Cycle
The Carbon Cycle
1. OVERVIEW
2. Change in CO2
3. Consequences – Global warming
4. Correlates
5. Perspectives
IPCC 2015 Report: “It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951 to There is high confidence that this has warmed the ocean, melted snow and ice, raised global mean sea level and changed some climate extremes in the second half of the 20th century.”