Unit 1: Carbon Cycle and Climate Change

biomineralization vs ocean acidification

Biomineralization is the normal process and is related to the carbon cycle. Ocean acidification is due to anthropogenic causes

which greenhouse gas has the highest concentration in the atmosphere?

CO2

what processes or fluxes move carbon from one part of the environment to another?

photosynthesis, respiration, consumption (eating), decomposition, combustion (burning), diffusion/dissolving, volcanism, and biomineralization

greenhouse effect

*Natural process* in which some of the heat radiating from the sun is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other greenhouse gases. This creates a warming impact on the Earth's surface

weather vs. climate

*Weather* - small scale: hrs, days *Climate* - large scale: months, yrs, longer - Winter is caused by the tilt of the Earth's axis — which isn't rapidly changing, so we will still have winter - Climate change does not mean that it won't be cold ever again - And while we're cold here in MA, other parts of the world (like Australia) are warmer than usual

GWP of CO2

1

how can climate change affect a population?

1. Migration - the population moves 2. Evolution - genetic change in the population 3. Extinction 4. Phenotypic plasticity - is the ability of one genotype to produce more than on phenotype when exposed to different environments

biomineralization and the carbon cycle

Corals, clams, mussels, and oysters make calcium carbonate (CaCO3) from carbonate and calcium ions dissolved in water. *CaCO3 = the hard parts of corals and shells of shellfish* - As more CO2 dissolves in ocean water, the ocean becomes more acidic and this *reduces the concentration of carbonate ions*, and can cause rates of biomineralization by coral to decrease and have a negative impact on coral growth. This is because with more carbon present, the chemical process that occurs ends up making bicarbonate rather than carbonate. This product is useless in biomineralization.

you are given 100 acres of land and asked to use the land for long-term reduction of atmospheric CO2 levels. Which of the following options is the *best* use of land for this purpose?

E) plant trees like poplar that grow rapidly, reach a large size, and live for a long time

If you are studying coral bleaching, what variables should you use?

IV: water temperature DV: photosynthesis rates

Where does a majority of a tree's dry biomass come from? How does this occur?

For plants, the majority of their biomass comes from the air. They take in CO2 through their leaves, which is then converted into a form of carbon that can be stored. Plants do not take in carbon through their roots, and the nutrients that they do take in make up a minimal amount of biomass.

Which of the following is true? I. The carbon from the primary producer turns into energy that is used to power the primary consumer II. The energy from the primary producer is incorporated into the body of the primary consumer III. Energy is lost as heat when the secondary consumer eats the primary consumer IV. Carbon starts in the atmosphere and is cycled back into the atmosphere through decomposition

III and IV

Temperature sex determination is an example of...

phenotypic plasticity

describe both natural and anthropogenic causes of CH4

Natural: Respiration (decomposition), sea vents Anthropogenic: Drilling for oil, rice paddies, landfills

describe both natural and anthropogenic causes of CO2

Natural: cellular respiration, combustion Anthropogenic: electricity production from coal-fired and natural gas power plants, transportation, and industry (burning fossil fuels)

food web

Primary consumers (herbivores) consume the primary producers. Secondary consumers eat primary consumers.

residence time of carbon in organisms vs fossil pool

The carbon stays in the reservoir of living organisms for a relatively short time, depending on their life span, from hours and days to years and decades. In contrast, the residence time of carbon in the fossil pool is dramatically different. Fossil fuels form over a course of 300-400 million years, forming from ancient plants and animals that decomposed slowly under very specific, anaerobic (without oxygen) conditions in wetland environments. Their bodies were gradually transformed by the heat and pressure of the Earth's crust into the fossil fuels that we mine today to provide petroleum oil, natural gas, and coal

what explains the annual oscillations in CO2 levels?

The regular oscillation of CO2 reflects the seasonality of photosynthesis in the Northern Hemisphere. During the spring and summer months, plants - especially trees in the northern boreal forests, take in CO2 and convert it into glucose. So there is more photosynthesis than respiration occurring and CO2 levels go down. In the fall and winter, rates of photosynthesis decrease but rates of respiration don't change and so there is an increase in atmospheric CO2 concentrations.

Why more rain (or snow) in some places?

Warm air holds more water than cool air. So warmer temps leads to more rain. Even though winters are getting shorter, it will still snow

combustion and the carbon cycle

When organic matter, such as wood, oil or coal is burned, carbon dioxide is given off into the atmoshphere

dead leaves on a forest floor will undergo ________ to return CO2 back into the atmosphere

aerobic decomposition

While CO2 is produced by aerobic cellular respiration, gases such as CH4 and N2O are often the products of __________ metabolisms.

anaerobic

The Earth's climate ________.Select one: a. has been stable (unchanged) over the history of the planet, but now it is changing rapidly. b. has experienced changes in the past due to natural (non-human) causes. c. will stabilize over the next century, according to the predictions of most scientists d. has changed only once due to the evolution of green photosynthesizing plants e. history is undeterminable because there is no method of studying climatic history of the planet

b

As oceans acidify, carbonate ions in the ocean...

become less abundant and less available to organisms that build calcium carbonate skeletons.

biomass

biological material derived from living, or recently living organisms. it is a much smaller reservoir of carbon

what are the two forces causing sea levels to rise?

both are caused by climate change: 1. the increased global temperature has caused increased ice melting in many regions of the globe. Melting land ice contributes to sea level rise because water that used to be stored in ice sitting on top of land becomes running water which reaches the ocean through runoff. Sea ice, such as the ice that covers the arctic regions of the Northern Hemisphere, has no land underneath it. When it melts, the water stays in the same location, and the overall sea level does not change. 2. *thermal expansion*. Due to the physical properties of water, as water warms, its density decreases. A less dense substance will have fewer molecules in a given area than a more dense substance. This means that as the overall temperature of the oceans increases due to global climate change, the same amount of water molecules will now occupy a slightly larger volume. This may not seem significant, but considering the 1.3 billion trillion liters (264 billion gallons) of water in the ocean, even a small change in density can have large effects on sea level as a whole.

Which of the following can be cycled in an ecosystem (the biotic and abiotic components of the environment)?

carbon *AND* atoms

When biofuels are grown they take in ________ from the atmosphere. When biofuels are burned, ________ is produced.

carbon dioxide for both

All carbon is continuously _______, while ________ is not.

cycled ; energy

Carbon dioxide in the air __________ into and out of water

dissolves/diffuses - CO2 in the atmosphere dissolves in the ocean where it forms carbonic acid which becomes *carbonate*.

true or false: Biomineralization utilizes organic molecules in order to obtain carbon

false

true or false: The greenhouse effect is bad for the earth and the result of human industrialization

false

How do greenhouse gases differ from each other

greenhouse gases differ in their sources and their residence time in the atmosphere, as well as their ability to produce the greenhouse effect (This is measured by the global warming potential, or GWP, of each greenhouse gas. The GWP of a greenhouse gas is based on its ability to absorb and scatter energy, as well as its lifetime in the atmosphere.)

ice sheets

huge slabs of ice and snow that cover large areas of *land*

Scientists have identified the source of our current global climate change as being the increased...

human-caused emissions of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), since the industrial revolution.

what besides agriculture also significantly contributes to CH4 emissions?

landfills contribute significantly to CH4 emissions, as the waste put into the landfill largely undergoes anaerobic decomposition as it is buried under many layers of trash and soil. Natural sources of CH4 include swamps and wetlands, and volcanoes.

Temperature and __________ are the two most direct impacts on the Earth's climate due to climate change.

precipitation

In a pond, tadpoles eat algae and fish eat the tadpoles. Around the pond, grasshoppers eat grass and are preyed upon by birds. Other birds eat the fish that eat the tadpoles. In this community, the tadpoles are...

primary consumers

Which of these organisms can incorporate atmospheric carbon directly into C6H12O6, thereby playing a major role in food webs?

primary producers

fluorinated gases

produced via industrial processes, refrigeration, and use of consumer products. Because these are synthetic chemicals that are only created by humans, these gases were essentially non-existent before the industrial revolution. They tend to have a long lifetime in the atmosphere, as seen in Table 6.1. Some of these chemicals, as well as the older chlorofluorocarbons (CFCs), have been phased out by international environmental legislation under the Montreal Protocol (see Chapter 5). Due to their long lifespan, many of these now banned CFCs remain in the atmosphere

specialists vs. generalists

specialists- use only a few types of food, narrow habitat range generalists- using most food types, broad habitat range

temperature anomaly

the difference between each year's average temperature and the benchmark; A positive anomaly indicates the observed temperature was warmer than the baseline, while a negative anomaly indicates the observed temperature was cooler than the baseline.

which reservoirs holds more carbon than all of the other reservoirs combined?

the lithosphere and ocean

coral bleaching

the loss of color in corals that occurs when stressed corals expel the algae that live in them; caused by warmer than average water temperatures which decreases photosynthesis by the algae.

the processes that move carbon from one location to another are called...

"fluxes"

These locations where carbon resides are known as carbon...

"pools", "sinks" or "reservoirs"

as global temperatures increase...

- weather patterns change - extreme weather events are likely to become more frequent and more intense - also change rain fall patterns

how is climate change altering plant and animal phenology?

*Plant phenology* = when budburst occurs, when flowers bloom, when seeds appear, etc. *Insect phenology* = when eggs are laid, how long eggs take to develop, how long larvae take to develop an example is that due to temperatures increasing, oak trees in the UK are producing leaves earlier on in the spring. Some flower species in Japan are budding earlier than when bumblebees come out of hibernation: "Long-term monitoring revealed that snowmelt timing dictates when Corydailis ambigua flowers. The earlier the snowmelt, the earlier the flowering. The researchers also found that bumblebees, which hibernate underground during winter, become active when soil temperatures reach 6 C. When the snowmelt is early, flowering tends to occur before the bees emerge, creating a mismatch. The wider the mismatch, the lower the seed-set rate due to insufficient pollination."

Changes to fluxes in the carbon cycle that humans are responsible for include:

1. increased contribution of CO2 and other greenhouse gases to the atmosphere through the combustion of fossil fuels (Fossil fuel combustion has increased dramatically over the past 100 years and is the major factor leading to the increase in CO2 concentrations in our atmosphere) 2. increased contribution of CO2 to the atmosphere due to land-use changes (intensive agricultural and forestry practices also contribute to the change in this flux) 3. increased CO2 dissolving into the ocean through ocean-atmosphere exchange 4. increased terrestrial photosynthesis.

Which of the statements about ocean acidification is FALSE? Select one: a. Ocean acidification increases the availability of carbonate ions in seawater. b. Increasing levels of CO2 in the ocean cause a decrease in the pH of seawater. c. Ocean acidification makes it more difficult for corals to secrete their skeletons. d. Ocean acidification is predicted to get worse as atmospheric CO2 levels rise.

A - ocean acidification *decreases* the availability of carbonate ions in seawater

One of the main substances in potatoes is the starch amylose ((C6H10O5)n). A potato is left outside and gradually decomposes. What could happen to the carbon atoms in the amylose molecules as the potato decomposes? A - Carbon atoms are converted into nitrogen and phosphorous which become soil nutrients. B - Carbon atoms are used up by decomposers and disappear. C - Carbon atoms are used up by decomposers and are released back into the atmosphere. D- Carbon atoms are turned into energy by decomposers.

A - this could NOT happen B - this could NOT happen C - this could happen D - this could NOT happen

Which of the following actions would reduce the amount of methane in the atmosphere either by reducing methane production or by removing methane from the atmosphere? A - Produce less waste so less trash goes to landfills B - People choosing to eat less beef. C - Reforestation (i.e. planting trees).

A - would reduce methane B - would reduce methane C - would Not reduce methane

what is the major contributor to CH4 emissions and why?

Agriculture is a major contributor to CH4 emissions. The gut of ruminant animals (such as sheep, cattle, and goats) has evolved to allow the animals to digest the very tough carbon molecules, such as cellulose, in grass. They do this through symbiosis, or cooperation, with anaerobic bacteria who live in the gut tract. These anaerobic bacteria produce methane and other gases as a result of their metabolism when they break down molecules like cellulose. This is sometimes called enteric fermentation. The methane gas is excreted from the animal, and this contributes significantly to total methane emissions. A similar type of bacteria live in the fecal matter, or manure, of livestock. As the manure is handled or stored for future use, methane is also released to the environment. *The demand for animal protein from meat, dairy, and eggs is very large in the United States.* As of January 2015, the United States had a total cattle inventory of 89.9 million animals, and in 2014, 25.5 billion pounds of beef was consumed in the United States (statistics: National Cattlemen's Beef Association). *The impacts of enteric fermentation and manure management for almost 90 million animals are significant.* In both cases, carbon that was previously stored in biomass (cattle feed) is moved into the atmosphere, this time in the form of CH4. This is another example of how humans have impacted the carbon cycle.

describe how temperature changes were in the past 400,000 years compared to present day.

Even though there were major fluctuations in CO2 concentrations and temperature in the past, these changes were slow compared to the changes happening now. *So while the Earth's climate has always been changing, the changes are now happening faster than in the past and now we (humans) are the cause.*

global warming vs climate change

Global warming refers to the increase in the average temperature of the Earth's atmosphere due to elevated greenhouse gas concentrations, heightening the greenhouse effect. Climate change refers to changes in other chemical, physical, and biological aspects of the Earth's environment. The consequences of climate change include changes in temperature, precipitation, ocean level, and ocean acidity. There are many more changes that have been seen, and are projected to continue in the future. These include: changes in the amount and distribution of ice and snow, changes in seasonality, ecosystem shift, and habitat changes of plant and animal populations, in addition to others.

You are studying the effects of ocean acidification on coccolithophores. You can grow coccolithophores in your laboratory in test tubes. You have space for 48 test tubes on your lab bench, in each tube you can grow one colony of coccolithophores. You can alter the following abiotic variables: water pH, temperature, salinity (salt concentration), light intensity, and the amount of dissolved oxygen (DO). You can measure the following variables: coccolithophores biomass, respiration rates, photosynthetic rates, and water pH. Your job is to design an experiment that examines the effects of ocean acidification on coccolithophores. What would be the best independent variable for this experiment? Dependent variable?

IV: water pH DV: biomass of coccolithophores since they won't be able to undergo the calcification process and thus may dissolve over time (decreasing biomass)

describe how we participate in the flux of carbon consumption when we eat food

The glucose, which contains the carbon, in the food is broken down to release ATP energy. The products of cellular respiration include the CO2 we exhale, water, and chemical energy that is stored in ATP. Our bodies also build additional biomass out of the carbon molecules in this food, allowing us to create new cells. This is the only way we, and all other *heterotrophs* ("other-eaters"), can bring in the carbon we need to build and maintain our bodies.

decomposition and the carbon cycle

The process of decomposition *releases CO2*. As plants and animals die and decompose, their bodies are consumed by decomposer organisms such as fungi and bacteria. The detritivore uses the dead animal or plant as food. The respiration of the detritivores releases CO2 or CH4. - In *oxygen-rich environments*, decomposers rapidly consume dead and decaying biomass using the same process of aerobic cellular respiration described above. - In *oxygen-deficient environments*, decomposers complete other metabolic pathways, and very slowly consume the organic matter. Methane (CH4) is a gas produced by anaerobic respiration of decomposers.

how does climate change impact precipitation patterns?

Water vapor is an important component of the Earth's atmosphere. As the air warms and cools, the amount of water vapor that it holds changes dramatically. Simply put, warmer air can hold more water than cooler air. As air cools, its ability to hold water vapor decreases, and any excess water will leave the air as liquid water. A great example of this is the formation of dew on surfaces overnight. During the day, the temperature is warmer than it is at night, and the air has a relatively high holding capacity for water vapor. When the sun sets, the air cools, decreasing its capacity to hold water vapor. That extra water must go somewhere, and it does that by accumulating on surfaces. Similarly, when warm and cool air fronts collide, the chances for rain and thunderstorms increase. Furthermore, an increase in temperature enhances evaporation occurring at the Earth's surface. This increased evaporation leads to greater concentrations of water vapor in the atmosphere which can lead to increased precipitation. - Also at play is the heightened evaporation rate of water on Earth's surface under warmer temperatures. More evaporation leads to more precipitation. - Finally, shifts in wind patterns impact the distribution of precipitation events.

Keeling Curve

a graph of the accumulation of carbon dioxide in the Earth's atmosphere based on continuous measurements taken at the Mauna Loa Observatory on the island of Hawaii from 1958 to the present day - *the level of atmospheric CO2 is increasing over time because of human activity, mainly the combustion of fossil fuels* - the increasing and decreasing levels of CO2 each year. The inset in the above figure zooms in on these annual oscillations (increases and decreases on a yearly basis) in CO2 levels. Each year the same amount of CO2 is removed from the atmosphere and then returns to the atmosphere.

Decide whether each of the following processes (fluxes) could move carbon into the atmosphere? a) Photosynthesis b) Respiration c) Combustion d) Consumption.

a) This could NOT move carbon into the atmosphere. b) This could move carbon into the atmosphere. c) This could move carbon into the atmosphere. d) This could NOT move carbon into the atmosphere.

one of the main substances in potatoes is the starch amylose. A potato is dropped outside and gradually decomposes. Which of the following describes something that could happen to these carbon atoms in the amylose molecules? a) the potato is consumed by a raccoon and the carbon is turned into energy b) respiration by decomposers releases CO2 in to the soil and the CO2 is taken up by the plant roots c) carbon atoms are incorporated into a mushroom (decomposer) that grows out of the potato d) photosynthesis by a decomposer takes in the carbon e) Carbon atoms are converted into nitrogen and phosphorous which become soil nutrients. f) Carbon atoms are used up by decomposers and disappear. g) Carbon atoms are incorporated into carbon dioxide.

a) false b) false c) true d) false e) false f) false g) true

True or false regarding plants and the carbon cycle: a) Plants undergo photosynthesis and respiration. b) At night, plants (regular C3 plants - don't make this more complicated by thinking about other types of photosynthesis) release CO2 into the atmosphere. c) Plants take in CO2 through the process of cellular respiration. d) Through the process of photosynthesis, plants convert glucose into carbon dioxide.

a) true b) true c) false d) false

Decide if each of the following statements explains the increase in CO2 concentrations over time. a) Increased combustion of fossil fuels like coal, oil, and natural gas. b) Deforestation and burning land to clear it for agriculture. c) Global rates of photosynthesis have increased over time. d) Global rates of photosynthesis have decreased over time. e) Human population size has increased which leads to more respiration by people.

a) yes b) yes c) no d) no e) no

The vast majority of N2O production by humans comes from...

agricultural land management. While some N2O is naturally emitted to the atmosphere from soil as part of the nitrogen cycle, human changes in land management, largely due to agricultural practices, have greatly increased N2O emissions. Some N2O is also emitted from transportation and industry.

ocean acidification and its effects

an increase in H+ concentration means a decrease in the pH of water. A lower pH means that the liquid is more acidic. An increase in CO2 in the atmosphere causes additional CO2 to be dissolved in the ocean. This means that more CO2 in the atmosphere leads to more acidic ocean environments. Unfortunately for shell-building animals, the buildup of H+ in the more acidic ocean environment blocks the absorption of calcium and CO32- (carbonate ions), and makes the formation of CaCO3 (calcium carbonate) more difficult. A CaCO3 deficit is already being documented in many of the world's oceans. The increasing acidity of the world's oceans is resulting in habitat changes across the globe. This is only expected to worsen as atmospheric CO2 levels continue to increase. Many organisms, including the corals that are the foundation species of the beautiful coral reefs, are very sensitive to changes in ocean pH.

As economic growth continued to increase, so did the production of __________. As human population size has increased, so has our impact on the planet.

carbon dioxide through fossil fuel combustion

true or false: The greenhouse effect is related to global warming due to increased absorption of heat by the earth

false

Plants and other photosynthetic autotrophs complete cellular respiration using the carbon molecules they...

formed from CO2 through photosynthesis. Any carbon molecules that are left over after the organism has acquired sufficient energy through cellular respiration make up the biomass of the plant.

decomposition

the process of dead animal or plant tissue being rotted or broken down by fungus, bacteria or other detritivores (decomposers)

why are plants and other photosynthetic organisms called *primary producers*?

they "fix" atmospheric CO2 into organic carbon, such as glucose, a form that is usable by animals and other organisms that need to consume their carbon molecules.

animals and other heterotrophs complete cellular respiration using the carbon molecules that...

they bring in through their food

The products of photosynthesis are oxygen and glucose. These glucose molecules are simple sugars that *autotrophs* ("self-feeders" like photosynthetic organisms such as plants, algae, kelp, etc.) can...

transform into other usable carbon molecules to build plant biomass or they can use these glucose molecules in process of cellular respiration

true or false: A lower pH of the water will cause a lower concentration of carbonate, therefore decreasing the rates of biomineralization

true

elevator to extinction

warmer temperatures → animals migrate further up → extinction

temperature sex determination

when the temperature of the embryo's environment influence its sex development