Greenhouse gasses

Atmosphere is a thin layer of gas held to the planet by gravity.

composed of mainly nitrogen 78%, 21% oxygen, argon, and water.

Change in net(down minus up) atmospheric radiation at the top of the troposphere.

amount that earth is out of energy balance.

energy balance gets restored in outgoing longwave radiation through stefan boltzmann feedback.

• -GHG have positive radiative forcing
• -CO2 has the largest radiative forcing of the anthropogenic GHGs
• -Radiative forcing ΔTs= λΔF

• -concentration of gas in atmosphere
• -frequency os absorption band relative to blackbody spectrum for earth
• -lifetime

• -prior to the pre industrial revolution, a steady state was maintained.
• -carbon cycle was balanced such that the distribution of carbon between reservoirs was not undergoing large changes.
• -emission of CO2 by humans disrupted that balance

The amount of carbon released to the atmosphere has been increasing (1.9 ppmv/yr)

Anthropogenic emissions are 130x greater than volcanic emissions:

• N = Forest fires, volcanic eruptions
• An = combustion of fossil fuels, deforestation

• -clearance of forests by logging and burning
• -releases C stored in above and below ground biomass and in soils
• -undisturbed forests hold 20-50 x more C than ecosystems that replace them

30%

• -13 million hectares per year, equivalent to area of costa rica.
• -20-25% of GHG emissions more than transportation emissions.

burning of fossilized organic matter to produce energy

• -natural gas
• -petroleum
• -coal

• water, energy, carbon dioxide
• //////////////////////////////////////////
• electricity generation, transportation, industrial

exchange of carbon between earth's atmosphere, ocean, vegetation, and soil that occurs over days to thousands of years.

- carbon is not destroyed, but redistributed, on human timescales

conversion by plants of inorganic carbon to organic  carbon

conversion by life of organic carbon to inorganic carbon.

incorporation of litter(dead plant leaves and roots) to soils.

escape of CO2 into the atmosphere through respiration/fermentation by plant roots, bacteria, fungi and soil animals.

• Exchange is driven by differences in co2
• -co2 dissolves in water
• -For every 10% increas in atmospheric co2 ,the surface ocean co2 will increase by 1%
• co2 exchange b/t surface ocean and atmosphere is fast(~1 year)

physical and chemical processes that transport inorganic carbon from the ocean surface to interior

physical and biological process that transport organic carbon from the surface to interior.