Lecture 11: Climate Change, C, CO2, Quiz Qs

Useful vocabulary

"Thermal" = thermal radiation or heat radiation "Solar" = solar radiation "TOA" = "Top Of Atmosphere.

greenhouse gas

-carbon dioxide -methane -nitrous oxide (N2O) -water vapor - Suns rays penetrate atmosphere - Earths surface radiates heat; greenhouse gasses absorb some heat and re-emit it back towards earth - We need greenhouse gases to keep earth warm (w/o them, earth would be ~60F colder) but because we are emitting so much CO2, more heat is being trapped, warming the earth

Terrestrial photosynthesis uses carbon in ________ from the ______ and energy from ______ to produce _______ that have ________ energy.

Carbon dioxide; air; sunlight; organic molecules; chemical potential

Which of the statements below is true regarding the movement of carbon between organisms in a food web, and the transfer of energy between organisms in different trophic levels? (Select all that apply.)

Carbon in the feces produced by a top predator can be decomposed and used by primary producers in the form of CO2; the energy in the feces is used by the decomposers and is released as heat. Carbon can be continuously cycled, but energy cannot.

In 2015, over 200,000 Saiga antelopes died in Kazakhstan, and researchers recently determined that a severe bacterial infection caused these deaths. 200,000 dead antelopes greatly changed the ecosystem processes occurring in the dry grasslands of Kazakhstan (48 degrees north latitude). Is the following statement likely or not likely to occur following the mass death of these animals? Decomposition rates in this cold, dry grassland will be higher than the decomposition rates in a tropical forest.

NOT LIKELY

From what you know about the global nitrogen cycle, what is one major way that humans alter this cycle?

by making nitrogen fertilizers and applying them to large areas

tracking weather

changing salinity can indicate whether the balance of rainfall and evaporation is shifting over broad regions of Earth. Consistent with many model predictions, wet areas of Earth are becoming wetter and dry regions drier.

who fixes (taking from atmospheric pool) carbon?

primary producers - taking inorganic CO2 from atmosphere --> organic molecules though photosynthesis

draw a figure representing how CO2 concentrations CHANGE SEASONALLY

squiggly curve - CO2 levels oscillate with the seasons - increases upwards long term 1. rates of PHOTOSYNTHESIS (removes some CO2 from the atmosphere) are HIGHER in SUMMER where as RESPIRATION (returns CO2 to the atmosphere) CONTINUES throughout the year - Fall is usually the lowest CO2 levels because summer just happened 2. more land mass in N hemisphere so global trends through the year are dominated by the N hemisphere organisms - contributes to long term trend

Which of the following equations depicts the chemical reaction for photosynthesis?

sunlight + 6CO2 + 6H2O --> C6H12O6 + 6O2

Describe the forms of carbon that can be used by photoautotrophs

take in CO2 and release O2

Most climate models predict that during the 21st century average (mean) global temperature will increase by:

1-4°C

Describe how carbon dioxide is added to the atmosphere.

Added: respiration (major), burning fossil fuels, burning wood, change in land use, decomposition; 1) geologic inputs, mainly from volcanoes and mid-ocean ridges, where CO2 is emitted as new seafloor forms 2) biological inputs, especially respiration 3) human activities, including deforestation and the burning of fossil fuels.

why is the amount of energy absorbed by the earth's surface (161 Watts/m2) lower than the amount of energy that enters the earth system through the outer atmosphere (340 Watts/m2)? Is this due to the greenhouse effect?

Arrow E < Arrow A because some of the energy is reflected, the reflected energy is shown by arrows B and F. This is not the greenhouse effect. This is reflected energy, like the reflection done by a mirror.]

All CO2 dip below 400ppm?

Atmospheric CO2 concentration will NOT dip below 400ppm again in our lives bc human burning fossil fuels has cause atmospheric CO2 concentration in a given month to increase every year

The largest source of nitrogen fixation on earth is accomplished by:

Biological nitrogen fixation, accomplished by some species of bacteria (including Rhizobium) and some species of Archaea

Describe how humans have altered the carbon cycle; define climate change

Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere. As a result, the amount of carbon dioxide in the atmosphere is rapidly rising. We have altered the LONG term carbon cycle How do we know? - when glacial ice forms, it traps tiny bubbles of air. Each year, snowfall gives rise to a new layer of ice, and as layers accumulate through time, their bubbles preserve a history of the atmosphere - CO2 in air bubbles trapped in Antarctic ice that has accumulated over the past 1000 years

methane

CH4 stable then recently increased dramatically

Which of the following statements is true regarding CO2?

CO2 is a greenhouse gas. CO2 is released as a product of cellular respiration. CO2 plays a vital role in maintaining Earth's temperature. CO2 can be produced by natural and man-made Correct answer: All of the statements regarding CO2 are true.

Give evidence that climate change is caused by humans.

CO2 levels remained consistent for thousands of years but began increasing with the industrial revolution (1750) and is still increasing at an unprecedented rate; Current CO2 level is not natural; fluctuations used to be caused by changes in earth's orbit around the sun but the level now is so abnormal that it has to be caused by something else; Clear increase in CO2 emissions due to fossil fuel burning and deforestation; 87% of global energy consumption 2013 was from fossil fuels

There is a giant sequoia (Sequoiadendron giganteum) named Washington (after George Washington) that was believed to be the second largest tree in the world (253.7 ft in height!) until it was struck by lightning in 2003. The lightning strike caused a fire at the top of the tree that reduced Washington's height to about 229 feet. What could have happened to the carbon released during the fire?

CO2 was taken up by a nearby tree, used in photosynthesis to produce a carbohydrate and sequestered (stored) in the biomass of the tree for a hundred years

Cellular respiration produces ______ from ________. Organic molecules are a source of ______ energy that cellular respiration transfers into _____ and transforms into _____.

Carbon dioxide and water; organic molecules and oxygen; chemical potential; usable chemical energy in the form of ATP; heat energy that cannot do work

During the polar vortex we had in Ann Arbor, Michigan in Winter 2019, your friend said that obviously global warming is not occurring because of the cold weather. He tells you he does not believe in climate change. Based on what you know about climate change, what would be the most biologically accurate response to your friend's comment?

Climate change is not short term changes in the weather, and climate change causes increased variability in several measures of climate including temperature, precipitation, and wind.

climate change

Climate is changing. This means that there is a significant change in patterns of climate, which include patterns in temperature, precipitation, humidity, wind - lasting for an extended period (decades or more) in a specified geographic region (e.g., North America).]

Distinguish between weather and climate.

Climate: long term patterns of temperature, humidity, wind, etc. in an area; influenced by latitude, altitude, terrain and nearby bodies of water. Weather: short-term state of temperature, humidity, wind, etc. in an area

Which of the following best describes the role of many of the fungi in an ecosystem?

Decomposers

Describe how decomposition moves carbon between pools

Decomposition allows carbon to be released back into the atmosphere, so it is short-term because the carbon does not stay in the organism forever

Why are carbon-based organic compounds, such as C6H12O6 glucose, often referred to as "high energy molecules"? Select all that apply.

Energy is released when carbon-containing compounds are broken down. Energy is required to build carbon-containing organic compounds. Organic compounds contain potential chemical energy.

Currently, atmospheric CO2 levels are the highest they have ever been in Earth's 4.5 billion-year history. Refer to Figure 46.7.

FALSE

Photosynthesis and respiration were the main causes of fluctuations in atmospheric CO2 levels over the last 500 million years.

FALSE

Describe the major fluxes of carbon

Fluxes: photosynthesis (largest) & respiration -terrestrial -marine Fluxes by humans (why CO2 level in atmosphere are increasing): -change in land use -fossil fuels

How are fossil fuels formed?

From the buried remains of ancient organisms *Not all detritus is successfully recycled by decomposers and detritivores - decomposes are especially INefficient in environments with low O2 levels - ex. bogs and swamps, where accumulated detritus may become buried and fossilized

Which of the following statements comparing fungal and animal nutrition is correct?

Fungi digest and then absorb food, whereas animals ingest and then digest food.

Explain how greenhouse gases cause the greenhouse effect.

Greenhouse gases are like a blanket over the earth that makes it warmer and traps heat. Sun's rays penetrate atmosphere, earth's surface radiates heat, greenhouse gases absorb some heat and re-emit it back toward earth, increase greenhouse gas traps more heat near earth's surface

Which of the following is true of gross primary production (GPP), net primary production (NPP) and cellular respiration? Choose all valid statements; there are two.

Gross primary production (GPP) can be calculated from NPP and respiration and, then, GPP can be reported in terms of energy per unit time per unit area Net primary production (NPP) can be measured and reported in terms of mass per unit time per unit area

Describe how we measure current and estimate historical levels of atmospheric CO2.

Historical: ice core drilled from glacier in antarctica, glacial ice contains small bubbles that trap samples of air and scientists can measure the CO2 in the bubbles; Current: measure the amount of carbon in the air with an IR sensor, Infrared sensing

Models created by scientists to simulate surface temperature changes were most accurate when they included ...

Human activities and natural processes

**QUIZ QUESTIONS**

LECTURES 7-11

greenhouse effect

Leading to climate change Greenhouse gasses TRAP HEAT energy radiated off the earths surface and reflect some of that heat energy back towards the earths surface

Which of the following factors influence(s) the rate of decomposition in an ecosystem? Choose all that apply.

Moisture levels Quality of detritus Temperature

In May 2015, at least 120,000 Saiga antelopes died in Kazakhstan, and researchers recently determined that a severe bacterial infection (pasteurellosis) caused these deaths. These dead antelopes greatly changed the ecosystem processes occurring in the dry grasslands of Kazakhstan (48 degrees north latitude). Which of the following statements is NOT likely to occur because of the mass death of these animals?

More nitrogen will be fixed by mycorrhizal fungi in the area where the antelopes died.

Describe how carbon moves up a food chain

Most of biomass is made of carbon; there is carbon in protein, fat, and glucose, when you eat an organism you harvest the carbon from the organism to build protein.

Which of the following statements most accurately describes the anatomy of a multicellular fungus?

Numerous hyphae make up a mycelium.

So-called "dead zones" in coastal oceans are associated with nutrient runoff and oxygen-depleted bottom waters. What causes the oxygen depletion?

Nutrient runoff enhances population growth rates of algae and cyanobacteria. When the phytoplankton cells die, this big pulse of detritus increases population sizes of decomposers which consume oxygen during cellular respiration.

Where are we going?

Oil and Gas are increasing Coal is changing trajectory renewables are increasing but starting from a low base

Explain the processes that drive the short-term carbon cycle

Photosynthesis and respiration drive the short-term carbon cycle using biological pools. Decomposition allows carbon to be released back into the atmosphere, so it is short-term because the carbon does not stay in the organism forever. During summer there is more sunlight and photosynthesis so there is less carbon in the atmosphere. Winter CO2 is higher.

What is a difference between a pool and a flux in a biogeochemical cycle?

Pools are measured in units of mass, whereas fluxes are measured in units of mass per time.

Explain what the best way is to slow climate change.

Reduce the amount of greenhouse gas production quickly, reduce burning of fossil fuels we are adding to the pool of atmospheric CO2, even if you balance the carbon flux the energy flux will still be a net increase. We need to stop putting carbon into the atmosphere but we also need to pull that carbon out of the atmosphere as well.

Describe how carbon dioxide is removed from the atmosphere.

Removed: photosynthesis, attempt to sequester carbon and store it, change in land use 1) geologic removal, especially by chemical weathering, in which CO2 in rainwater reacts with exposed rocks 2) biological removal, mainly through photosynthesis, in which CO2 is turned into organic molecules used for growth and reproduction.

Describe the major reservoirs of carbon

Reservoirs: sediments/rocks (largest), surface water, atmosphere, terrestrial organisms, organic matter (a lot here), deep sea water (second largest) C moves between these reservoirs through a variety of processes, including photosynthesis, burning fossil fuels, and simply releasing breath from the lungs.

Charles Keeling's work demonstrated that, over the last five decades, atmospheric CO2 levels have (collectively) increased. Refer to Figure 46.1.

TRUE

Plant cells can transform chemical potential energy of sugar (e.g., glucose) into heat and use some of the remaining chemical potential energy to do work.

TRUE

The long-term and short-term carbon cycles are connected by the fact that some of the carbon contained in C6H12O6 (or other organic molecules) in plants is incorporated into sedimentary rocks or oil; it is not immediately reintroduced back into the atmosphere.

TRUE

Your body, your home, and your pets could all be considered carbon reservoirs.

TRUE

Give evidence demonstrating that climate change is happening now and that it impacts more than just temperature.

Temp: Average global temperatures have risen by about 1.4 F over the past 100 years, Recent deviations in temperature are warmer, temperatures are increasing, "Climate change is a direct threat to the national security of the U.S," Drought/Floods: California has years of drought, extreme flooding, heat waves (fires) Food insecurities Sea level rising: problems with coastal communities and storm surges Acidity: Oceans are getting more acidic because the chemistry of the ocean is changing which affects predator/prey interactions in acidic water, More extreme heat waves and droughts, Heavy precipitation: more frequently (hurricanes) - heat rises, more condensation, sea level rising, dangerous storms

biosphere

The part of the Earth where living things thrive and live. It is the portion of the planet that can sustain life.

How do fungi obtain macromolecules, like sugars and amino acids, needed for growth and metabolism? Choose all that apply:

They secrete digestive enzymes to decompose dead organisms they come into contact with They absorb digested macromolecules (which are digested by secreted digestive enzymes)

Xylem sap is fluid that circulates around a plant that contains inorganic nutrients and water. Imagine you are comparing the nutrient content of xylem sap from two plants: one with mycorrhizae and one without mycorrhizae. How would you expect the nutrient content of these two xylem samples to differ?

Xylem sap from the mycorrhizae sample will have more phosphorus.

Why is atmospheric nitrogen so inaccessible to most organisms?

because the nitrogen molecules have a triple bond between two nitrogen atoms, and plants cannot take up nitrogen (N2) gas

Which processes return CO2 to the atmosphere, balancing photosynthetic removal?

aerobic respiration = oxygen to oxidize organic molecules to CO2, converting chemical energy in the organic molecules to ATP for use in cellular processes

weather

average weather over a long time interval From one year to the next, weather varies tremendously: there will be cold years and warm years, wet ones and dry ones. Because weather is so variable, evidence for climate change comes not from individual weather events but rather from records kept over decades.

flux

flowing; a continuous moving

Based on these figures, the very high rates of primary production in the oceans happen ____, while the highest rates of primary production on land happen______.

in coastal areas; around the equator

If phosphate concentrations were to suddenly increase in a freshwater ecosystem, which of the following would likely occur in the short term?

increased primary productivity

Conversion of N2 gas into NH3 (ammonia) is accomplished by which of the following types of bacteria? NH3 (ammonia) in water forms NH4 (ammonium) which primary producers can take up and use.

nitrogen-fixing bacteria

If rates of nitrogen fixation increased tenfold in aquatic ecosystems, would you expect a tenfold increase in primary productivity?

no, because there are other limiting nutrients in aquatic ecosystems besides nitrogen (e.g. phosphorus)

fossil fuel

organic carbon (C) that didn't get broken down long time ago

dispersal

the movement of organisms from one place to another