Terms in this set (187)

1. Changes in incoming solar insolation
our current sun is warmer than our sun was 4.56 GA
Solar luminosity has increased through time
2. Configuration of continents
Drake Passage is an opening where South America and Antarctica used to be connected
Formed due to spreading and regional tectonics over the last 20-40 million years
This impacted modern circulation by allowing the Antarctic Circumpolar Current to form, which circles Antarctica
This impacted our entire global circulation system and resulted in cooling at high southern latitudes
3. Changes in albedo/reflectivity
Isolation of Antarctica would have impacted its albedo
When we form snow, it reflects incoming solar insolation → drives global cooling
Albedo is highly variable globally
4. Changes in our atmosphere
our atmosphere is varied in composition
Major greenhouse gases are:
Water vapor
Carbon dioxide
Nitrous oxide
Fluorinated gases
Cause warming to the Earth mainly exist in troposphere → closest layer to the Earth
Greenhouse Effect
Sun emits solar radiation
Passes through the atmosphere unchecked and hits the surface of the Earth
It may be reflected back into space (especially from surfaces with high albedo) or may be absorbed and re-radiated as infrared radiation
Infrared radiation can then trapped by greenhouse gas molecules
Some infrared heat escapes into space and some gets radiated between molecules
By these actions, greenhouse gases serve as an insulating blanket for Earth → they catch re-radiated heat and warm the surface of the Earth and the lower atmosphere
We need this effect or the Earth would be very cold and would have no liquid water, and possibly life
5. Plate tectonics and weathering
Drop in carbon dioxide when Himalayas formed because weathering caused erosion and created new minerals
Most (non-sedimentary) rocks on the Earth's surface form under high temperature and pressure conditions
When they are exposed to lower temperature and pressure conditions at the Earth's surface, they are no longer stable and break down
These reactions produce new minerals
Water + carbon dioxide = carbonic acid
Carbonic acid + silicate rocks = clays, bicarbonates, and other ions
Animals take the bicarbonates and other ions, make their shells, die, and sink to the seafloor
We can cool global climate by locking up atmospheric carbon dioxide in carbonate rocks, which are made of the skeletons of organisms