FInal Study Guide 13 Flashcards
Long Term Climate Variation
What is the carbon cycle?
Carbon begins in the atmosphere in some form. It can be taken in by plants in the form of CO2 in order to perform photosynthesis. When this organic matter dies and is buried. This waste fossilizes and its carbon can be burned for energy. There are many different ways to release carbon from organic matter. Burning wood is another example. Release this carbon puts it into the atmosphere, restarting the cycle.
Why does the carbon cycle act as a thermostat for Earth climate?
- The carbon cycle acts as a thermostat because it maintains Earths temperature and creates a thermal blanket. The carbon cycle is only possible on Earth due to plate tectonics.
- Self Regulating system (negative feedback)
- As CO2 increases, temperature increases
- As temperature increases, rate of weathering increases
- As weathering increases, Levels of CO2 decrease
- Weathering reaction important, more efficient at higher temperatures
What is the faint sun problem?
- We hypothesize the sun is much larger and brighter now, so in early Earth when the sun was fainter, why wasn’t the Earth frozen over? There are two hypotheses.
> The first is that there could have been a greenhouse effect that was substantially larger causing more erosion and the release of CO2.
> The second suggests (the change in terms of albedo) there is more whiter stuff now that reflects the sunlight so that even though the sun burns hotter and brighter now, the Earth today is reflecting more back.
Ice record
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Temperature proxy
above
Isotope
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Deuterium
- one of two stable isotopes of Hydrogen
- natural abundance in oceans
Ice Age
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Natural Climate Change
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Eocene Optimum
little to no ice was present on Earth with a smaller difference in temperature from the equator to the poles
Meteorite forcing
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Carbon cycle
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Tectonic forcing
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Volcanism
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Pleistocene Ice Age
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Interglacial
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Holocene Maximum
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Faint sun
- Sun has changed its luminosity over time (amount of radiation that goes out)
- Star burns heavier and heavier fuels over time increased radiation
- Even though the Sun was about 30% dimmer than it is now, temperature on Earth has been more or less stable
- It should have been so much colder because the sun was so much fainter due to carbon cycle
Luminosity
measure of brightness, can be measure in terms of radiant power, i.e solar luminosity
Albedo
Reflectivity of a surface, typically that of a planet or moon. Like the snow that reflects the sunlight to prevent the surface of the earth from overheating.
Continental Formation
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Organic carbon
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Carbonic acid
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Calcium carbonate
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Weathering
breaking down of rocks, soils, and minerals as well as artificial materials through contact with the Earth’s atmosphere, biota, and waters. Weathering occurs in situ, or “with no movement”, and thus should not be confused with erosion
Mineral resources
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Sediments
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Thermostat
The Earth can’t get too hot or too cold during the carbon cycle
Negative feedback
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Positive feedback
- Positive feedback (albedo) can produce runaway extreme climate.
- Extreme climate can cause evolutionary bottleneck
Photosynthesis
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Snowball earth
650 million years ago, whole surface of the earth was covered by snow. It was the 2nd of the last time when all continents together
Cap carbonate
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Oceanic Carbon Cycle
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Respiration
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Fossil Fuels
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Coal
a hard black mineral which is dug out of the ground and burnt to produce heat
Oil
a smooth thick liquid that is used to make machines run easily or is burned to produce heat
Carboniferous
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Anthracite
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Lignite
referred to as brown coal, is a soft brown combustible sedimentary rock that is formed from naturally compressed peat. It is considered the lowest rank of coal due to its relatively low heat content.
Bituminous Coal
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Oil Trap
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Impermeable
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Permeable
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Saturation
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Anticline
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Salt Dome
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Energy Use
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Renewable energy
energy generated from natural resources – such as sunlight, wind, rain, tides and geothermal heat – which are naturally replenished. Ranges from solar power, wind power, hydroelectricity/micro hydro, biomass and biofuels for transportation
Non-renewable
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Reserves
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Resources
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Deposits
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Economic
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Subeconomic
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Peak Oil
the point in time when the maximum rate of petroleum extraction is reached, after which the rate of production is expected to enter terminal decline
Hubbert’s Curve
an approximation of the production rate of a resource over time
