Week 9. Unit 3. Climate
Oxygen isotope ratios preserved in ______ can be used to reconstruct the climate of the past. (Select all that apply.)
the ice crystals of glaciers the shells of fossil marine organisms
As atmospheric levels of carbon dioxide (CO2) rise, more CO2 dissolves in the ocean. This has a negative effect on marine ecosystems because ______.
the oceans become more acidic, which makes it harder for corals to build their shells and form coral reefs
The geological rock record is full of climate change evidence, including coal deposits that indicate ___ temperatures and glacial deposits that indicate ___ temperatures.
warm, cold
Why can the proportion of calcium carbonate (CaC03) in marine sediments be used as a climate proxy? The proportion of calcium carbonate in marine systems is related to the ______.
water temperature
The temperature, pressure, and precipitation conditions of the atmosphere for a specific place on a given day is called ___, whereas a longer term view of these same factors, typically taken over a period of many years, is called ___
weather, climate
The 2014 Intergovernmental Panel on Climate Change projected that average temperature at earth's surface would rise by 0.3 to 4.8οC (0.5 to 8.6οF) by ______.
2100
Which of these would be considered weather events, as opposed to climate? (Choose all that apply.)
A heat wave strikes Atlanta, Georgia, causing many people to experience heat exhaustion. A high amount of rainfall over the course of a weekend causes flooding in downtown Nashville, Tennessee. Vancouver, British Columbia, experiences a very warm winter and doesn't receive enough snowfall for Winter Olympic events.
What is permafrost?
A layer of permanently (year-round) frozen ground
Which of the following statements are true about the concentration of carbon dioxide (CO2) in earth's atmosphere? (Select all that apply.)
Carbon dioxide levels were far higher during earth's warm periods than they are now. Current CO2 levels are the highest they have been in the history of modern humans.
Which of the following statements accurately states the distribution of effects related to climate change?
Changing wind-flow patterns and amounts of precipitation will cause differential impacts in different areas.
Which of the following statements accurately describes thermohaline circulation?
Cold saline waters sink in polar regions because they are dense and then travel great distances until they rise and connect to surface circulation.
Which of the following statements accurately compares modern levels of atmospheric carbon dioxide (CO2) levels to the concentrations recorded in ice cores over the last few hundred thousand years?
Current CO2 levels are high, but not the highest of any recorded in ice cores.
Which of the following are clear evidence of past climate change? (Choose all that apply.)
Dunes that formed in a desert are now covered in vegetation. Coal deposits found under glacial deposits North Africa switching from a wheat-growing region during the Roman Empire to being a desert at the empire's end.
True or false: All layers of the atmosphere (troposphere, stratosphere, etc.) have experienced a warming trend over the last few decades.
False
True or false: Glacial ice and trapped air bubbles are the only two known sources of preserved oxygen isotopes that are useful as climate proxies.
False
What are the likely effects of climate change that will influence humans? (Select all that apply.)
Farming could become impossible in areas where it is possible now. Water shortages may occur in areas that rely on glacial meltwater.
If a mass of water is traced over time and becomes isotopically lighter than it was and then isotopically heavier than it had just been, what likely happened to the water?
It evaporated and then condensed.
Identify characteristics of nations that are more likely to be strongly affected by climate change. (Select all that apply.)
Low elevation Economically poorer Less developed
Which of the climate feedback mechanisms described below lead to cooling? (Select all that apply.)
Marine organisms absorb carbon dioxide used to build their shells at a slower rate. There is an increase in the average albedo (reflectivity) of earth's surface.
What event can occur in thermohaline circulation that can "abruptly" change climate in the North Atlantic region?
Melting of the Greenland ice sheet could result in a pool of fresh surface water that would block surface water coming up from the south.
Which of the following statements accurately describes the regional effects of global climate change?
Not all regions will experience similar changes in climate as the global climate changes.
How do oceans moderate climate change?
Oceans are large thermal reservoirs; they release heat during cold phases and absorb heat during warm phases.
What is the difference between direct temperature measurements and proxy data used as evidence for climate change?
Proxy climate data comes from the recorded responses of past climate change, whereas direct evidence indicates current climate.
What is the ultimate source of energy that drives earth's climate?
Radiation from the sun
How can the average surface temperature of earth best be determined?
Record the temperature at one spot for a year and determine the average, and then average it with other locations around earth.
What would happen to sea level if all of the world's ice melted?
Sea level would rise by about 75 meters without even accounting for thermal expansion of the water.
Which of the following "geoengineering" solutions have been proposed to reduce global warming?
Sending millions of tons of soot into the stratosphere each year
How will farms or farming be affected as the climate changes? (Select all that apply.)
Some farms will experience better growing conditions as they will have longer growing seasons. Some farms will experience poorer growing conditions as the temperatures get too high and soil moisture is reduced.
How does rising atmospheric CO2 levels affect photosynthetic organisms (e.g., plants)? (Select all that apply.)
Some marine phytoplankton are negatively affected as the oceans warm as a result of the excess CO2. It causes some photosynthetic organisms to grow more quickly while having no effect on others.
What are some of the challenges associated with determining the global surface temperature of earth? (Select all that apply.)
Temperature can be rather different from year to year on any given day. There are more direct temperature observations on land as compared to the ocean, and they exist over a longer period of time. Temperatures can fluctuate significantly over short distances.
Why is determining the global surface temperature of earth difficult?
Temperature variations occur over time and distance.
Which of the statements below accurately describes the distribution of warming that has occurred over the last few decades in earth's atmosphere? (Select all that apply.)
The Arctic has experienced more warming than lower latitude areas. The troposphere has warmed at all levels.
Which two of the factors listed below are the most important in determining climate?
The amount of solar radiation released by the sun The amount of solar radiation that reaches earth's surface
Why can changes in oxygen isotope ratios be used as proxies for climate?
The fractionation process is temperature-dependent with greater fractionation at lower temperatures.
How are coral reefs and the marine ecosystems that depend on them negatively affected by rising concentrations of carbon dioxide (CO2) in the atmosphere? (Select all that apply.)
The increased atmospheric temperature causes the ocean to warm. The dissolved concentration of CO2 increases, which causes the formation of increased amounts of carbonic acid.
How has global climate change affected the occurrences and distribution of pests (e.g., mosquitoes, bacteria, parasites, etc.) that transmit or cause diseases? (Select all that apply.)
The number of diseases caused by disease-carrying pests has increased. Diseases transmitted or caused by pests have expanded into new areas.
Which of the following are true about atmospheric carbon dioxide? (Select all that apply.)
There are many natural processes that remove carbon dioxide from the atmosphere. The concentration of carbon dioxide in the atmosphere is increasing.
Which of the following are true about ice-core climate records recovered from Greenland and Antarctica? (Select all that apply.)
They both display a correlation between greenhouse gases and temperature. Both record a similar pattern of climate change indicating that ice cores do capture global climate trends. The Greenland ice-core record extends back about 160,000 years.
What are characteristics of water vapor? (Select all that apply.)
Water vapor absorbs infrared radiation. Water vapor is the most abundant greenhouse gas.
Water has a high heat capacity, meaning it can absorb or release a lot of energy without changing its temperature. This means the oceans are able to release or absorb a lot of energy, and in this way, they ______.
moderate climate change
The greenhouse effect ______.
occurs when infrared energy radiating upward from earth's surface is trapped by the atmosphere
When looking at an ice core, a single year will be represented (optimally) by ______.
one light layer and one dark layer
If water evaporates, ______ will preferentially become water vapor. If water vapor then condenses and falls as precipitation, it will be enriched in ______ relative to the remaining water vapor.
oxygen-16; oxygen-18
In many alpine and high-latitude locations, the ground surface is often marshy during the summer; meltwater cannot drain into the earth because of the layer of frozen ground called ___ that exists in the soil.
permafrost
Since the start of the Industrial Age, global surface temperatures on earth have ______.
risen about 1.1οC
Surface temperatures on earth have been ______ since the start of the ______.
rising; Industrial Age
A decline in the relative proportion of calcium carbonate in a core of marine sediment may indicate the climate was ______.
cooling since calcium carbonate dissolves more readily in colder waters
Natural processes fractionate oxygen isotopes because the isotopes ______.
differ in mass
Evidence such as thermometer records from measuring atmospheric temperatures is called ______ evidence for global warming, whereas evidence from other types of observations that allows us to infer past temperatures is called ______ evidence.
direct; proxy
Fertilizing the oceans to promote phytoplankton growth, spraying seawater over the oceans to encourage cloud formation, and putting soot in the atmosphere to block sunlight are all ___ ideas to deal with climate change.
geoengineering
Climate change is likely to affect economically poorer nations to a ______.
greater degree since they have fewer resources and less access to medical care
The changing oxygen isotope ratios in the shells of marine organisms are a reflection of temperature changes of the water because ______.
greater fractionation occurs at lower temperatures
Some of the solar radiation that makes it through the atmosphere is absorbed at earth's surface and results in it warming. The warm surface radiates heat energy back upward, and some of that energy is absorbed by various atmospheric gases causing them to warm. We call this process the ___ effect.
greenhouse
The burning of wood, coal, oil, and natural gas releases carbon dioxide. This release of carbon dioxide and other compounds is causing the rise of ___ gases in the atmosphere.
greenhouse
The gases that absorb infrared rays in the atmosphere are called ______ gases.
greenhouse
The mass difference between oxygen-16 and oxygen-18 is ______.
large enough to cause fractionation in natural processes
How do we make atmospheric temperature surveys of large areas?
by using satellites
Rapid cooling could occur in the North Atlantic region if ______.
an influx of meltwater due to rapid warming disrupts thermohaline circulation
Which projection below matches the one made by the 2014 Intergovernmental Panel on Climate Change about the climate of 2100? Global temperatures will be ______οC warmer.
0.3 to 4.8
Identify ways in which modern climate data is collected. (Select all that apply.)
Air temperatures are recorded at different altitudes within the atmosphere. Air temperatures are recorded on land and over the oceans. Satellites are used to remotely determine temperatures over large areas.
Identify the consequences if all of the existing ice melted on earth. (Select all that apply.)
Approximately 20% of the currently exposed land would be submerged. Millions, if not billions, of people would be displaced.
Temperatures recorded all over the surface of the world are ______ in order to determine the surface temperature of earth.
averaged
The distinguishing characteristic of greenhouse gases is that they ______ infrared radiation.
absorb
True or false: All photosynthetic organisms will benefit from more carbon dioxide in the atmosphere.
false
