unidirectional changes
evolution of the solid earth and oceans and atmosphere and life.
cyclic changes
rock cycle wilson cycle (supercontinent cycle)
greenhouse gases
CO2 and methane, key roles in controlling earth's climate, heat cannot escape into space from atmosphere.
warm the earth's climate and the lower atmosphere
greenhouse effect is will
paleoclimate
...
oxygen isotope ratios
...
(1)measure past climate change, (2) use models to predict how changes in atmospheric conditions, ocean currents, earth's orbit, and human activity will lead to changes in climate
what are the two ways to study climate change?
paleoclimate
process where climatologists look at sedimentary record, paleontological evidence, and growth rings
oxygen isotope ratios
Ratio of 18 oxygen to 16 oxygen in glacial ice gives indication of temperature at which ice was formed. (larger ratio = warmer temperature)
oxygen isotope ratios
can take successive measurements to figure out temperature change through time
greenhouse
times in Earth's past when it was much warmer than today
ice house
times in earth's past when it was much colder than today
ice age
cold enough for ice sheets to advance and cover large areas of the continents
position of continents, volcanic activity, tectonic uplift, formation of fossil fuels, life evolution
what causes long term climate change to happen? (5 answers)
position of continents
influences ocean currents, if land is getting more/less sunlight (latitude), and size of continental interiors
volcanic activity
increased activity may put more greenhouse gases into the atmosphere
tectonic uplift
weathering rates change (use CO2) and change atmospheric circulation
formation of fossil fuels
removes CO2 from atmosphere, put into energy reserves instead
life evolution
appearance or extinction of certain types of life can also change CO2 levels
short term climate change
over the last 15000 years, there have been ups and downs in temperature but a general increase in temperature overall.
fluctuations in solar radiation and cosmic rays, changes in earth's orbit and tilt, changes in volcanic emissions, changes in ocean currents, changes in surface albedo (reflectivity)
possible causes of short-term climate change are?
fluctuations in solar radiation and cosmic rays
changes the amount of solar energy received by earth
changes in earth's orbit and tilt
...
changes in volcanic emissions
...