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III. BIOGEOCHEMICAL CYCLES Overview The Water Cycle The Carbon Cycle 1. OVERVIEW. RESERVOIRS: Most atmospheric carbon has been transferred to the hydrosphere (dissolved CO 2 ) and lithosphere (limestone and fossil deposits). Dead and dissolved organic matter are other large reservoirs
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III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW
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
FLUXES: Flux between hydro and atmo is still a major exchange reservoirs in gigatons and exchanges in GT/year
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
III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW • 2. Change in CO2
Decrease due to terrestrial plant evolution and Carboniferous storage
- last 160,000 years (ice cores) 401 280
- Since 1000: up 43% (all since 1830 – industrial revolution)
III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW • 2. Change in CO2 • 3. Consequences – Global warming
2. Since 1860 – increase of 0.8oC – ten hottest years all since 1991
III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW • 2. Change in CO2 • 3. Consequences – Global warming • 4. Correlates
Reductions in Polar Ice (area covered) 1979 Nasa.gov 2003
Reductions in Polar Ice (thickness) - deep sea ice depth decreased from mean of 3.1 meters in 1958 to mean of 1.8 m in 1997 Nasa.gov
Reductions in polar ice • Reductions in glacial ice B-15 is the size of Connecticutt (2000)
- Icebergs calving off Ross Shelf – April 2000 (B15 is 4,280 miles2 – about the size of CONNECTICUT….)
Reductions in polar ice • Reductions in glacial ice
Reductions in polar ice • Reductions in glacial ice • Sea level rise
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…
- More big storms: March 24, 2004 – Atlantic Cyclone off Brazil.
- More big storms: March 24, 2004 – Atlantic Cyclone off Brazil. (earthobservatory.nasa.gov) “The South Atlantic is generally not thought of by meteorologists as a place where tropical cyclones can form. The water temperatures are generally too cool and the vertical wind shear too strong. The area is so devoid of tropical storm activity that no government agency has an official warning system for storms there, which is why this storm is unnamed.”
- More big storms “Natural disasters caused by extreme weather claimed seven times as many victims in 2003 as in the previous year and the trend is set to continue, says the world's biggest reinsurance company. (They insure insurance companies.) Munich Re said global warming would cause increasing economic damage in the future. "It is to be feared that extreme events which can be traced to climate change will have increasingly grave consequences in the future," the report said, adding that insurance premiums would rise and that clear-cut indemnity limits would be needed.” – Reuters New Service, Feb 27, 2004
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.
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
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)
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. - Dengue fever, which was present in only nine countries in the 1970s, is now found in more than 100, most likely the result of increasing urban populations.
III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW • 2. Change in CO2 • 3. Consequences – Global warming • 4. Correlates • 5. Perspectives
5. Perspectives - Canadian Environment Minister David Anderson said that global warming posed a greater long-term threat to humanity than terrorism because it could force hundreds of millions from their homes and trigger an economic catastrophe. – March 2004 World bank: “global warming requires immediate action” (2003) - commissioned an independent panel to investigate options. - Recommendation: “The WBG [World Bank Group] should aggressively increase investments in renewable energies by about 20 percent annually. WBG lending should concentrate on promoting the transition to renewable energy..." • The World Bank rejected the recommendation. 2004 energy lending dedicates 6% to renewables, 94% percent to oil. In FY 2013, the Bank provided nearly US$7 billion in energy lending, including US$2.7 billion in fossil fuels (39%), US$1.7 billion in clean energy (24%), and US$2.6 billion (38%) in “other” energy projects, such as large hydropower or transmission projects.
5. Perspectives “We need an energy bill that encourages consumption.” -President G. W. Bush, Sept. 23, 2002, Trenton, NJ The Pentagon Report (2004): global warming “should be elevated beyond a scientific debate to a US national security concern.” It declares that “future wars will be fought over the issue of survival rather than religion, ideology or national honour.” – Fortune magazine – March 2004.
III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW • 2. Change in CO2 • 3. Consequences – Global warming • 4. Correlates • 5. Perspectives • 6. Methane
6. Methane “Globally, over 60% of total CH4 emissions come from human activities… Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2 over a 100-year period.” (EPA) Livestock
III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • 1. OVERVIEW • 2. Change in CO2 • 3. Consequences – Global warming • 4. Correlates • 5. Perspectives • 6. Methane • 7. IPCC – 2013-14 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 2010. 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.”
3900 GT • III. BIOGEOCHEMICAL CYCLES • Overview • The Water Cycle • The Carbon Cycle • The Nitrogen Cycle ULTIMATE RESERVOIR: Atmosphere – N2 = 78% by volume, 75% by weight, of dry air.
FLUXES: Atmospheric nitrogen is “fixed” by bacteria on land and in marine/aquatic systems; the N atoms are separated and H bonds, creating Ammonium ions (NH4+).
FLUXES: Atmospheric nitrogen is “fixed” by bacteria on land and in marine/aquatic systems; the N atoms are separated and H bonds, creating Ammonium ions (NH4+). Ammonium can be converted to Nitrite (NO2) and Nitrate (NO3) by nitrification; also a process only performed by certain bacteria in terrestrial and marine environments.