HELP PLEASE!!! ESPECIALLY PART 2

2. The following questions do not require the data above. Answer with the data given in each question.

i. There is a total of approximately 12.4 billion acres of agricultural land (cropland, rangeland, irrigated land) on the major continents. Given that the average Net Primary Productivity (NPP) of agricultural land is approximately 2900 kcal m-2 y-1 calculate the annual global NPP associated with these lands (your answer should be reported in SI units, i.e. Joules) [2 marks]

ii. Assume that animals (humans and domesticated animals) have a 10% energy conversion efficiency and that we need approximately 2800 kcal d-1 to survive. How many i) Human Vegetarians and ii) Human Omnivores could the planet presently support (for simplicity assume that 50% of the energy content of the omnivore diet comes from meat or meat products). Comment on the implication of this calculation. [4 marks]

To calculate the annual global NPP associated with agricultural lands, we need to multiply the total agricultural land area by the average Net Primary Productivity (NPP) value.

i. Given that the total agricultural land area is approximately 12.4 billion acres and the average NPP is approximately 2900 kcal m^-2 y^-1, we can convert the land area from acres to square meters:

1 acre = 4046.85642 square meters

So, the total agricultural land area in square meters would be:

12.4 billion acres * 4046.85642 square meters/acre = X square meters

Next, we can multiply this land area by the average NPP value to calculate the annual global NPP:

X square meters * 2900 kcal m^-2 y^-1 = Y kcal y^-1

To convert Y from kilocalories (kcal) to Joules (J), we need to multiply Y by the conversion factor:

1 kcal = 4184 J

So, the annual global NPP in Joules would be:

Y kcal y^-1 * 4184 J/kcal = Z J y^-1

This is your answer for part i.

ii. To calculate the number of Human Vegetarians and Human Omnivores that the planet can support, we need to consider the energy conversion efficiency and energy requirements.

Assuming animals (including humans and domesticated animals) have a 10% energy conversion efficiency, it means that only 10% of the consumed energy is converted into useful energy for growth and maintenance.

Given that we need approximately 2800 kcal d^-1 to survive, we can calculate the total energy requirement in Joules:

2800 kcal d^-1 * 4184 J/kcal = W J d^-1

Since there are 365 days in a year, we can multiply W by 365 to get the annual energy requirement:

W J d^-1 * 365 d y^-1 = X J y^-1

Now, let's calculate the energy available from the agricultural land:

The total energy available from the agricultural land would be the annual global NPP (calculated in part i) multiplied by the conversion efficiency:

Z J y^-1 * 0.1 (energy conversion efficiency) = Y' J y^-1

To determine the number of Human Vegetarians that the planet can support, divide Y' by the energy requirement for a Human Vegetarian:

Number of Human Vegetarians = Y' J y^-1 / W J y^-1 = Z'

To determine the number of Human Omnivores that the planet can support, we need to consider that 50% of their energy content comes from meat or meat products. So, the energy requirement for a Human Omnivore would be:

W J y^-1 * (1 + 0.5) (for the additional energy from meat) = W' J y^-1

Divide Y' by the energy requirement for a Human Omnivore to calculate the number of Human Omnivores:

Number of Human Omnivores = Y' J y^-1 / W' J y^-1 = Z''

This is your answer for part ii.

The implications of this calculation depend on the values Z' and Z''. If Z' and Z'' are significantly lower than the current global population of Human Vegetarians and Human Omnivores, it suggests that the planet's resources are overused and cannot sustain the current level of consumption. It may indicate the need for more sustainable food production practices and dietary choices to ensure the long-term viability of the planet.