3A The carbon Cycle

1850- and 2015

ATM concentrations have risen from 290 ppm t0 400 ppm

Speed up warming, cause a POSITIVE FEEDBACK LOOP

ATMOSPHERIC CO2 RISES

Deforestation and land use

influence carbon cycle

Land use (rice paddies) and deforestation

outstrip reforestation by 1 GT per year

Biosphere (Terrestrial Plants and Soil)

plants (biomass) inhale CO2 and exhale O2. When there's more CO2 available, biomass tends to breathe in more, and therefore grow more. Most scientists now believe that plants have a limited ability to increase their growth rate.

Even with no further input from humans

the elevated levels of atmospheric CO2 caused by a century of fossil fuel burning will continue to impact the carbon cycle because the system attempts to reach a state of equilibrium, with the exception of the gradual moving of carbon from the surface to the deep ocean, which happens only over longer time-scales. It could take 2000 years or more for this process to restore atmospheric CO2 to pre-industrial levels.

Linear relationship

any given change in an independent variable will always produce a corresponding change in the dependent variable

Directly proportional

as one amount increases, another amount increases at the same rate.

Atmosphere

combustion of carbon-based fuel combines carbon, C, and oxygen, O2, adding CO2 to the atmosphere. CO2 is not a by-product of fossil fuel use; it's the direct product of the very reaction that releases the energy.

Atmospheric carbon levels significantly lower

How have atmospheric carbon levels changed?

stored carbon enter the system

If arctic tundra were to melt as temp rises

- Increase the atmospheric amount, - Increase the amount of deforestation that occurs each year (4GT/yr = 8GT/decade= 80GT/century)

If only one half of the flora in the world existed in 2110 (perhaps due to deforestation), what do you predict the atmospheric carbon level would be ? How would you change the simulation to reflect this?

- can also be found in the ocean, atmosphere, and soil - In fifty years, you would be most likely to see excess carbon in the soil

In addition to circulating through the carbon cycle, where else might excess carbon be found? In fifty years, where would you be most likely to see excess carbon?

- carbon levels in soil will still increase

In fifty years, if deforestation were decreased 50%, how would the carbon levels in the soil change?

- Terrestrial flora population increased - The carbon level in the soil is getting higher by decade and it increases the number and variety of terrestrial plants and animals, due to the increase of carbon dioxide in the soil

Lesson 3, step 1: By 2090, how has the terrestrial flora population changed? What is the carbon level in the soil and how does the carbon level affect the flora populations and species variety?

Deep ocean

Ocean chemistry involving mineral precipitation, and biological activity, and ocean currents transport the carbon from the surface ocean to the deep ocean over long time-scales.

2.5%

Rate of increase has been our recent experience for the increase in global energy use

Less than 2 GT per year (1.6)

Realistic deforestation estimates

Increase in atmospheric co2 levels

Relevant human impact

Surface ocean

The amount of gas dissolved in any liquid is proportional to the partial pressure of that gas in the vapor phase above the liquid (Henry's Law). As a result, if we increase the partial pressure of atmospheric CO2 (i.e. increase the concentration of CO2), then we force more CO2 gas to dissolve into the liquid. (In this case, the liquid is the ocean.) In addition to the CO2 dissolving into the liquid as a gas, CO2 reacts with H2O and forms bicarbonate ions (HCO3-) and carbonate ions (CO3--). This combustion of fossil fuels results in an increase in dissolved surface ocean carbon and a decrease in pH.

- NOT LINEAR - 2.5% increase in fossil fuel use in each of 100 years, total decrease of 83%, total Atmospheric carbon goes up 68%

Using the data generated by the simulation, determine the mathematical relationship between the percentage increase in fossil fuel consumption and the increase in atmospheric carbon. Is the relationship linear?

Carbon levels in gaseous carbon, ocean water, biosphere gaseous carbon will all decrease

WHAT WOULD HAPPEN IF THERE IS NO FOSSIL FUEL CONSUMPTION

- High concentrations of carbon dioxide make it harder for marine animals to respire (to extract oxygen from seawater). This, in turn, makes it harder for these animals to find food, avoid predators, and reproduce. Low concentrations of oxygen can have similar effects.

What effect does a high carbon level have on the deep ocean? Why might it be important to keep an eye on the deep ocean carbon levels? What could that one number tell you about the cycle as a whole?

- increase in fossil fuel consumption, carbon in terrestrial plants increase - increase in flora populations

What is the relationship between an increase in fossil fuel consumption and increased carbon in terrestrial plants? How might this change flora populations? What impact could twenty years at this level of consumption have on flora?

- As carbon concentration increases, so does carbon in the ocean surface - Bad for the atmosphere - Fifty years at this level of emission will damage marine fauna and flora

What is the relationship between an increase in total carbon concentration (the smokestack) and increased carbon in the ocean surface? How might this change marine life populations? What impact could fifty years at this level of emissions have on marine fauna? On marine flora?

- Direct relationship (as you increase 1, you also increase the other) due to the terrestrial plant and oceanic plankton requirements of water, nutrients and CO2. - Can be transferred by fertilizers and water runoff from mountains

What is the relationship between increased carbon in the ocean and increased carbon in the soil? How else might carbon be transferred to soil?

Terrestrial plants to atmosphere then rest of carbon cycle

Where will carbon be transferred first?

- soil and atmosphere - The increase in the atmosphere will increase the temperatures and could make it harder for us to breath - Need the gases so our temperature will not be freezing - The increase in the soil will allow some plants to grow.

Which areas are most highly (and quickly) affected by an increase in carbon emissions (and increase in fossil fuel consumption)? How would these effects manifest themselves? What are the dangers/benefits to these areas?-

- ocean surface, deep ocean, soil - increase in carbon level but improved for the deep ocean

Without any fossil fuel consumption, which parts of the cycle have improved their carbon levels in comparison to previous data? Which sections of the cycle have improved from the previous levels you have recorded but still are increasing their carbon levels?