CO2 emissions between 1990-2012 have greatly increased via international transportation,
developing countries ad so on. Decreases have been made by the EU and US but mainly due to
Recession.
Measurements
Keeling Curve: Mauna Loa, Hawaii
South Pole
Fluctuations smaller due to depressed climate
Remote and isolated from local effects
Both show an increase in CO2 in the atmosphere despite annual cycle
flucuations of respiration and photosynthesis.
Proxy records of Atmospheric CO2
Ice core records where bubbles of gases form in ice allowing us to analyse atmosphere back to 780,000 years
Vostok Record
Founded Milankovitch cycles of 400,000 years
CO2 reaching 400ppm, first time reached
since 3-5million years ago when humans
were not about. (2-3 celsius higher)
Causes
Fossil Fuel combustion
Cement manufacture (CaCO3 = CaO + CO2)
Deforestation (reduced uptake and increased respiration)
Agriculture (slash and burn techniques and change to less
carbon fixing crops (cash crops such as palm trees).
Greenhouse Effect
Incoming solar radiation (short and long wave) adsorbed by Ocean and
land (51%), Atmospheric gases (19%)
Remaining radiation scattered or reflected. Land and Ocean re-emit to atmosphere but
long (infared) re-adsorbed in atmosphere, only short wave escapes.
Earth's atmosphere converts retained solar energy into heat. Without, temperatures would be 4 celsius
Consequences
Link to CO2 and temperautre via geological records
Climate warming? Strong evidence from UK Met Office, US NOAA and US NASA that it is
Artic sea ice reducing
Northern hemisphere snow anomaly reducing
Ocean heat increasing
Sea levels rising abow 1993-1999 average to 70mm higher by 2015
Future Predictions
Intergovernmental Panel on Cimate Change (IPCC) set up by UN and WMO with 2,500 scientists and technical experts report 2013
Increasing CO2 conc, temperature increase, sea level rise. 2 degrees rise in Arctic region, no place will experience no change
Role of oceans
Amount of C in atmosphere=2.0 x 10 power 16 moles
Amount of C in oceans: 2.5 x 10 power 18
Huge sink for partitioning C
Enhanced Oceanic uptake of CO2: Ocean Acidification
Evidence: CO2 dissolves in SW to form carbonic acid. Absorption of anthropogenic CO2 lead
to decease in pH. Consequences with CO3 tests, nutrient cycles.
Oceans as a sink for CO2
Long periods of time, acts as a sink for inorganic and organic C.
Transfer of C to deep ocean is called SEQUESTRATION
Gets there via physical processes and Biological Pump
Biological Pump
Combined biological processes transfer organic matter and associated elements to depth for rapid C sequestration.
Quickly removes C from surface ocean and atmosphere. Without pump, 200ppmv increase in atmospheric CO2
Solubility Pump
Deep water formation in to upwelling out
SUMMARY: Direct measurements of atmospheric CO2 go back no more than 60
years. Longer records via ice cores 780,000. Present CO2 close to 400ppm
unprecedented in past 1 million years (humans and societies evolved) . Higher
atmospheric CO2 led to global warming, decline in Arctic sea ice extent, increase
heat of upper ocean leading to sea level rise. Oceans absorb 1/3 of CO2 resulting
from human activities (anthropogenic) due to biological and solubility pumps.