[20 pts] While the control variable for novel entities remains undefined, evidence suggests it is transgressed, and defining a control variable is essential for operating within the planetary boundary. In this context, analyze each control variable approach, describing one strength and one weakness, while discussing the criteria that inform the selection of control variable options (i.e., feasibility, relevance, comprehensiveness).

a. [10 pts] Trend in the production of plastics.

b. [10 pts] Trend in release quantities of plastics into the environment.

[20 pts] Novel Entities.

a. [10 pts] Provide one example of a “truly” novel entity and explain whether such a substance can be considered a Planetary Boundary Threat. Describe how each condition (i.e., persistence, mobility, and potential impact) is met or not.

b. [10 pts] Several novel entities are released in the environment due to improper solid waste management. Describe two solid waste management strategies, and explain which strategy would be preferred over the other.

[20 pts] While both Nitrogen (N) and Phosphorus (P) constitute fundamental building blocks of life, they have different characteristics and natural cycles.  

a. [10 pts] Explain how Nitrogen is naturally made available for plants, and how humans have influenced the Nitrogen cycle.

b. [10 pts] Explain how Phosphorus is naturally made available for plants, and how humans have influenced the Phosphorus cycle.

[20 pts] The biogeochemical flows boundary reflects anthropogenic perturbations of global element cycles, which currently include Nitrogen (N) and Phosphorus (P).

a. [10 pts] Explain why the global anthropogenic imbalance of biogeochemical flows poses a planetary boundary threat.

b. [10 pts] Describe how the Furman Farm serves as a model for mitigating the global anthropogenic imbalance of biogeochemical flows.

What are limitations of using exposure or disturbance-based variables for novel entities? Select ALLthat apply.

Why is the trend in chemical production volume considered a feasible control variable? Select ALL that apply.

Which statement describe the current status of the planetary boundary for novel entities? Select ONEchoice.

Which criteria are proposed for selecting control variables for novel entities? Select ALL that apply.

What are challenges associated with defining a planetary boundary for novel entities? Select ALL that apply.

[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 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 direction of flow between the groundwater well and the stream. Is the aquifer recharging or discharging water in the stream?

b. Calculate the total stream discharge in m³/s. 

Equation:

Flow (Q) = velocity (v) x area (A).