on 1.Life Earth is based on which one of the six elements which are essential for
life on Earth?
- Carbon
2.Where on Earth does carbon cycle? On what time scale(s)?
- Carbon cycles through the oceans and the biosphere over both short and long
term scales.
3.The geological carbon cycle takes how long? In this cycle, carbon cycles
through what?
- The geological carbon cycle takes place over hundreds of millions of years and
involves the cycling of carbon through the various layers of the Earth.
4.The biological carbon cycle takes how long? The biological carbon cycle
involves what three processes?
- The biological carbon cycle occurs over days, weeks, months and years and
involves the absorption, conversion and respiration of carbon by living
organisms.
5.Weathering combines carbonic acid (CO2 plus water) with calcium and
magnesium and the product is what? Is this product soluble in water? Review
soluble and insoluble if forget what these terms mean.
- The product is insoluble carbonates. No it is not soluble in water.
6.Erosion sends this product where?
- Erosion sends the product into the ocean and they eventually settle to the
bottom.
7.Then, what happens to this product, by the process of subduction? Define
subduction.
- The product is drawn into Earths Mantle by subduction which is defined as a
process in which one lithospheric plate descends beneath another, often as a
result of folding or faulting.
8.Carbons geological cycle is completed when it returns to the atmosphere. In its
geological cycle, how does carbon return to the atmosphere? What form is
carbon in, when it returns to the atmosphere? Give the phase and the chemical
formula of this compound.
- Carbon is returned to the atmosphere during volcanic eruptions in the form of
carbon dioxide. This phase is called volcanism and the chemical formula is CO2.
9.What three processes control the balance of atmospheric carbon dioxide
concentrations over time periods of hundreds of millions of years?
- Weathering, subduction and volcanism.
10.What is the first step in the biological carbon cycle? In this process, inorganic
atmospheric carbon is converted into what?
- Photosynthesis is the first step in the biological carbon cycle. Inorganic
atmospheric carbon is converted into a biological form.
11.From where is the energy to run this process obtained?
- Energy from sunlight is used to run this process.
12.In oceans, photosynthesis is carried out by what organisms? How big are
these organisms?
- In oceans, photosynthesis is carried out by microscopic aquatic plants called
phytoplankton. These organisms are tiny and can only be seen by a microscope.
13.Living plants and animals expel carbon dioxide from their bodies as a by
product of what process?
- Respiration
14.The carbon in dead bodies of plants and animals returns to the atmosphere
by the action of what organisms?
- The carbon in dead bodies of plants and animals returns to the atmosphere by
the action of microorganisms called decomposers.
15.Explain how humans tap into the geological carbon cycle. What is the result of
these human activities?
- Humans tap into the geological carbon cycle by extracting oil and coal for use in
automobiles and power plants. This results in an increase of the carbon dioxide
level in the atmosphere, mostly as a result of human use of fossil fuels.
16.Explain how humans have altered the biological carbon cycle. What is the
result of these human activities?
- Humans have altered the biological carbon cycle through forest clearing and
land use. This increases atmospheric CO2 levels.
17.Naturally-occurring trace gases in Earth atmosphere include: list the
substances given in this article.
- water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
18.Explain how human activity impacts the concentrations of these gases in the
atmosphere.
- Human activity impacts the concentrations of these gases in the atmosphere by
use of industrial products, including solvents, adhesives, and pesticides.
19.Is the full range of sources of greenhouse gases both natural and
anthropogenic fully understood, at this time? Greenhouse gases continue to be
the subject of what two human activities?
- It is not fully understood at this time and continues to be the subject of both
research and debate.
20.The most greenhouse abundant gas is water vapour. Temperature affects the
concentration of water vapour in Earths atmosphere. Describe the positive
feedback loop effect of rising temperatures on atmospheric water vapour
concentration.
- Higher temperature cause more water to evaporate from ground sources. Since
the air is warmer, the relative humidity can also be higher, leading to more water
vapour in the atmosphere. Higher concentrations of water vapour are able to
absorb more thermal infrared radiation from the Earth, which warms the
atmosphere more. The warmer atmosphere can then hold more water vapour
and the cycle continues.
21.Atmospheric concentration levels of carbon dioxide have increase by nearly
what percentage, between the late 18th century and present time? What is the
parts per million (ppm) increase?
- They have increased by nearly 30 percent between the 18th century and the
present time. The ppm increase is 370.
22.Methane is a more powerful atmospheric warming agent than carbon. What is
the time frame of the methane cycle in the atmosphere; how long is methanes
lifetime in the atmosphere?
- Methane is in the atmosphere for only about 12 years.
23.How is methane naturally released into the atmosphere? What anthropogenic
activities have contributed to the rise in atmospheric concentration of methane?
- Methane is naturally released into the atmosphere through biological processes
in low oxygen environments such as swamplands. Anthropogenic activities such
as growing rice, raising cattle, using natural gas and coal mining increasing add
to the level of methane in the atmosphere.
24.Since the beginning of the 19th century, atmospheric methane concentrations
have risen by what percentage? Fortunately, atomospheric methane
concentrations have not increased since what year? Do scientists know why?
- Methane levels have risen 150 percent since the 19th century. They have not
increased since 1990 and scientists do not know why.
25.Nitrous oxide has a long lifetime in the atmosphere; how long? What are the
natural and anthropogenic sources of atmospheric nitrous oxide?
- Nitrous oxide has a lifetime of 120 years. Natural sources include biological
sources in both soil and water. Anthropogenic sources include agricultural soil
management, animal manure management, sewage treatment, combustion of
fossil fuel and the production of a variety of acids.
26.What is ozone? Ozone atmospheric concentrations vary by what two factors?
- Ozone is a highly reactive molecule composed of three atoms of oxygen.
Ozone concentrations vary by both geographic and altitude.
27.Why is ozones role in the overall enhancement of the greenhouse effect
difficult to determine?
- Ozones role in the overall enhancement of the greenhouse effect is difficult to
determine because it contributes to both the warming and the cooling of the
atmosphere.
28.What are halocarbons? What is the most familiar type? Humans use
halocarbons primarily for what three purposes?
- Halocarbons are compounds of human origins used primarily as cooling agents,
propellants, and cleaning solvents in a broad range of applications. The most
familiar type of halocarbons are chlorofluorocarbons (CFCs).
29.What is the full name of HFCs? Why do HFCs have less of an impact as a
greenhouse gas?
- The full name of HFC is hydrofluorcarbons. They have less of an impact as a
greenhouse gas because they are less stable in the atmosphere.
30.Why is the ultimate impact of halocarbons on the greenhouse effect highly
uncertain?
- The ultimate impact of halocarbons on the greenhouse effect is highly uncertain
because at lower altitudes, halocarbons function as a warming gas, and in the
upper atmosphere they exert a cooling impact through their interaction with the
ozone.
31.Some countries are clearly much worse polluters than others. Which countries
are leading in CO2 emissions? What type of habits or lifestyle causes increased
CO2 emissions? Who must step up and be the leaders in the solution, according
to The Breathing Earth website?
- Western countries are leading the way in CO2 emissions.
- Western lifestyles and habits have caused CO2 emissions to raise and nonwestern countries with high CO2 emissions have adopted Western habits.
- Western citizens must step up and be the leaders to the solutions.