5 Written questions
5 Matching questions
- what has a higher albedo, ice or land?
- How do CO2 levels today compare with those of the last 400,000 years?
- what is the composition of foraminifera shells (or tests)?
- what are some of the consequences of climate change- which we are already seeing?
- what is the greenhouse effect?
- a highest its ever been
- b foraminifera is a skeleton made of CaCO3 (same as calcite) oxygen isotope rations depend upon water temp; these tiny, single celled organisms are sensitive to even small fluctuations in temperature; seafloor sedimetns containing fossils such as this are useful recorders of climate change
- c ice
- d the atmosphere warms the planet and makes Earth livable; the important role it plays in heating earth's surface is called the greenhouse effect: this energy heats the air and increases the rate at which it radiates energy, both out to space and back; think of short-wave UV coming in, long-wave radiation going back up from the surface as heat, these waves are absorbed by greenhouse gases, including CO2, methane, and others). We are most concerned about CO2 because we are adding it to the atmosphere in the greatest amounts, and it accumulates (does not dissipate for hundreds of years)owards Earth;
- e hard to predict specific regional changes because increased levels of CO2 but consequences include:
(1) altering the distribution of the world's water resources
(2) a probable rise in sea level
(3) a greater intensity of tropical cyclones
(4) changes in the extent of Arctic sea ice and permafrost
5 Multiple choice questions
- (1) seafloor sediments- contain remains of organisms that one lived near sea surface; useful recorders of worldwide climate change
(2) oxygen isotope analysis- based on precise measurement of the ratio bt 2 isotopes of oxygen; O^16 is most common and the heavier O^18: O^18/O^16 ratio in shells of microorganisms- past temperatures
(3) climate change recorded in glacial ice
(4) tree rings- archives of environmental history
(5)fossil pollen, corals, historical data
- heavy isotope increases relative to light isotope at cooler temperatures (O18/O16 goes up).
- positive feedbacks are changes that reinforce the initial change
ex: warmer surface temperatures can cause an increase in evaporation, which further increases temperature as the additional water vapor absorbs more radiation emitted by Earth
- the hotter the radiating body, the shorter the wavelength of maximum raidation
- by analyzing pollen from accurately dated sediments, it is possible to obtain high-resolution records of vegetational changes in an area because pollen and spores are parts of life cycles of many plants and are easily identifiable
5 True/False questions
stratospheric ozone → ozone near the earth's surface (the troposphere is the lowest ~12 km of the atmosphere) - and affects us adversely when levels get to high. This is because ozone (O3) is a strong oxidizer. Tropospheric ozone is created from an interaction between sunlight and pollutants such as nitrous and sulfur oxides - in our area, most of these pollutants come from combustion in vehicles burning fossil fuels. But, a certain (regulated) amount is emitted from power plants as well. Ozone alerts (or Ozone action days) in Dallas are days when tropospheric ozone concentrations are higher than acceptable for good health. These are nearly always during the summer months.
what are aerosols? how might they influence climate? → tiny, often microscopic, liquid and solid particles that are suspended in the air. Aerosols act directly by reflecting sunlight back to space and indirectly by making clouds "brighter" reflectors
how do we know what the concentration of atmospheric CO2 was during past glacial and interglacial cycles? where do these samples come from? → changes in carbon dioxide and methane are linked to fluctuating temperatures. the cores also include atmospheric fallous such as wind-blown dust, volcanic ash and modern day pollution
can you figure out why O18 increases (relative to O16) in the tests of foraminifera during cold intervals, but decreases (relative to O16) during cold intervals in water samples from ice cores? → the hotter the radiating body, the shorter the wavelength of maximum raidation
what are other, natural sources of CO2 and aerosols? → plate tectonics, variations in earth's orbit involving shape, obliquity and precession, volcanic activity and changes in sun's output associated with sunspots