Describe one way that the planetary boundary framework can be applied in practice.

The terrestrial biosphere’s preindustrial Holocene Net Primary Production (NPP_Holocene) average has been determined at 55.9 Gton C/year. For a given year, the global Net Primary Production remaining after appropriation (NPP_eco) was estimated at 51 Gton C/year.

a.  [10 pts] Explain what is the Human Appropriation of Net Primary Production (HANPP) and how it influences the biosphere integrity.

b.  [10 pts] Calculate the control variable value (% HANPP) for the functional component of the biosphere integrity boundary and determine if the planetary boundary is transgressed.

The pre-human background extinction rate was estimated to be close to 2 Extinctions per 1 million species-year (E/MSY). Between 1900 and 2014, 477 species of vertebrates were extinct, extinct in the wild or possibly extinct considering 39,223 species evaluated.

a. [10 pts] Calculate the rate of vertebrate extinctions (in E/MSY), compare with the background rate, and explain its meaning considering our knowledge about previous mass extinctions.

b. [10 pts] Discuss the environmental and anthropogenic factors influencing biodiversity in one natural habitat and one disturbed habitat on Furman campus.

Anthropogenic modifications of the Earth system have significant impact on water quantity and water quality. Analyze the hydrologic cycle below and answer the questions for each area of interest.

a. [10 pts] Describe how agriculture (indicated by the red rectangle in the figure) disturbs blue water quantity, green water quantity, and surface water quality. 

b. [10 pts] Describe three agriculture strategies that can be implemented to mitigate the impacts on surface water quality and nutrient imbalance. 

a.  [10 pts] Explain why gaseous chlorofluorocarbon (CFC) compounds are considered novel entity substances and a Planetary Boundary Threat. Describe how each condition (i.e., persistence, mobility, and potential impact) is met or not met.

b.  [10 pts] Explain why plastics are considered a Planetary Boundary Threat and describe three solid waste management strategies for mitigating plastic pollution. Rank the strategies from most preferred to least preferred.

The figure shows the En-ROADS model used to study climate prediction, mitigation, and policies.

a.  [10 pts] Explain how choices regarding energy supply influence the Earth’s climate and describe two strategies that can be simulated in the En-ROADS model to mitigate the impacts of energy supply on climate change. 

b.  [10 pts] Explain how land system change influences the Earth’s climate and describe two strategies that can be simulated in the En-ROADS model to mitigate the impacts of energy supply on climate change.

[10 pts] The figure shows a groundwater well in an unconfined aquifer (left) and a stream (right). The surface near the well is located 2.00 m above the bottom of the stream. During a visit to the well, you measured the depth to water and obtained a value of 1.75 m. After you have conducted a streamflow measurement and recorded the data as shown in the table. Analyze the stream and groundwater data collected in the field and answer the questions.

a. Calculate the water level in the groundwater well and determine the direction of flow between the groundwater well and the stream. Is the aquifer recharging or discharging?

b. Calculate the total stream discharge in m³/s. Note that flow (Q) = velocity (v) x area (A).

[10 pts] A soil profile with 18 cm (depth) and two horizons. Horizon A is 7 cm deep and has 2.5% of carbon per mass of soil. Horizon B is 11 cm deep and has 1% of carbon per mass of soil. The bulk density of the soil is equal to 1.6 g/cm³.

Calculate the total soil carbon stock to 18 cm per area (in ton C/ha). 

Equations and conversion factors:

Stock per Area = Mass / Area

1 ton = 1,000,000 g = 10⁶ g

1 ha = 10,000 m² = 100,000,000 cm² = 10⁸ cm²

[10 pts] The table shows the diameter at breast height (DBH) for eight hardwood, deciduous trees collected in a 5-meter radius area, as well as the aboveground dry biomass (bm) calculated with the equation from Jenkins et al. (2003). 

 Calculate the total tree carbon per area (in ton C/ha). 

Assume that 50% of the aboveground dry biomass is carbon, and the ratio of 30% of root per aboveground dry biomass. 

Equations and conversion factors:

For Hardwood (maple, oak, hickory, beech): 

Area of a circle = π r² 

1 ton = 1,000 kg

1 ha = 10,000 m²

[20 pts] Carbon is the chemical backbone of all life on Earth. While the total amount of carbon we have on Earth does not change, carbon moves between the atmosphere and other carbon reservoirs such as rocks (solid and interior Earth), land (biosphere), and oceans, greatly influencing the Earth’s climate. 

a. [10 pts] Explain how weathering of rocks can act as stabilizing (negative) feedback on atmospheric CO₂, including two factors that influence the rate of weathering.

c. [10 pts] Explain what role carbon plays in the Earth's energy balance.