SET721 Engineering Sustainability Assignment 2: Factors and Solutions

This assignment explores key aspects of engineering sustainability, addressing population growth, climate change, and renewable energy solutions. The first question delves into the factors influencing population growth, its impacts on environmental sustainability, and includes calculations on population projections for China and India, highlighting discrepancies between predictions and reality. The second question focuses on global warming, explaining the greenhouse effect, global warming potentials (GWPs), and calculating carbon dioxide emissions. The third question presents calculations related to renewable energy, including the land area needed for large-scale wind and solar energy projects. The assignment covers topics from population dynamics to the effects of climate change and the need for renewable energy sources.

ENGINEERING SUSTAINABILITY
By Name
Course
Instructor
Institution
Location
Date

Question 1
Factors affecting the size and growth of the population
Economic development: higher population growth rates have been observed within countries at
early phases of economic development.
Education: education is mandatory to most of the developed countries for children below 16
years, and therefore they are not considered to be economic assets but costs.
Children quality: mostly, the choice on number of children by the parents depends on marginal
cost and benefit analysis (Alkama & Cescatti 2016)..
Social and cultural factors: before implementation of the policy of one family in countries like
china and India, large families were preferred but in the current developed countries small
families is the trend.
Family planning: the contraceptives currently used by women have made it possible to reduce
the size of the family to the level of desire. Developing countries however experience low supply
of contraceptives resulting into high population growth (Kazimierski et al.2018).
Death rates: this is reduced frequently prior to reductions in birth rates resulting to a rise in the
size of the population at a given time of the economic development of the country.
Levels of immigration: the net migration greatly determines the population growth of some
countries.

Historical factors: before the periods of war, a stout unity existed between nations leading to rise
in sizes of the population.
Figure 1: showing the factors affecting population growth in the current economy
Impacts of population growth on Environmental Sustainability
There is a closer interrelation between environmental impacts and population growth which
tends to be very complex. Some of the challenges of sustainability which are related to the
population growth include the following:
Farming impacts-There is continuous need on the expansion of the agricultural base to support
the growing populations (Creutzig et al 2017). The result is high deforestations rate so that new
farm lands can be created and the consequences are basically negative on the environment. Also
the use of chemicals like pesticides in the control of pests leads to the destruction of the ozone
layers and pollution in general.

Eutrophication- Surface runoff from the agricultural farmland finds their destination into water
bodies where they provide nutrients to the ocean weed thereby promoting their growth (Najafi,
Zwiers, & Gillett 2015). These weeds affect the lives of other aquatic organisms through
completion for food and oxygen
Global Warming
The growth in the human populations as well as changes in the climate have actually grown
hand in hand since there is use of fossil fuels to support industrialization programs which are
known to sustain the populations,.
Part b
Taking the compound interest formula;
A=P(1+r/n)nt
Population size=9860000000(1+2/100)20
Taking the constant increase in the population to be 2% per year , the population of India will be
approx.. 1.5billion;
1.5=1.2(1+r/100)20
Log1.5= log 1.2(1+r/100)20; Dividing both sides by 1.2
The equation becomes;
1.25=(1+r/100)20

Taking the root, the Rate will be equal to 1.12%. This implies that the population of china
should grow by 1.2% for it to match that of India in the next 20 years.
Part C
The processes of prediction of the population take into account several assumptions. Some of the
assumptions made include that the country has not undergone any calamity, political instability
among others which are known to affect the population growth rates (Pecl et al.2017). In reality,
there are several dynamics which the country undergoes which makes the population growth rate
not to be constant. As a result there is a lot of discrepancy as well as the real growth of the
population.
Question 2
Part a
The process of greenhouse effect is natural and results into global warming. When the energy
from the sun strikes the atmosphere, though large amounts get reflected to the space, some are
however radiated and reabsorbed by the greenhouse structures. This energy absorbed results into
warming effect on the surface of the earth as well as the atmosphere (Hu et al.2016). This effect
of global warming is as a result of persistent increase in the average climatic temperature of the
earth. It is a great feature displayed by the changes in the climatic conditions as has been directly
depicted by evaluations on temperature as well as evaluation on other warming effects. The
terms, climate change and global warming can be used in [place of the other. Change in climate
which may also be referred to as global warming is the average increase in the temperature of the
earths’ surface (Sands et al.2017).

The devastating agreement made by scientists is that the change in climatic conditions is as a
result of usage of fossil fuels among the human race which results into the emission of
greenhouse gases like carbon dioxide to the atmosphere. These gases encloses heat within the
ecosystem resulting to great effects on the earths’ surface like extreme weather effects, a rise in
sea level alongside droughts which will dispose the terrain to wildfires.
The processes of the climate change as well as global warming affects the agricultural activities
since the pattern of rainfall is reversed. Also there is case of prolonged drought which affects the
activities as well. Also eutrophication is attributed to the global warming and it has ben identified
as a major threat to the fishing activities (Harvey 2016).
Part b
Global Warming Potentials (GWPs) are the quantity of measure of the relative global effects
which impress on a precise gas produced from the greenhouse. It is regarded as an aggregate
factor that impresses on both indirect and direct upshots- incorporated for given duration from
the point at which the a relative amount of gas equivalent to that of reference is emitted to the
atmosphere (Bulkeley & Newell 2015). The set gas for reference by IPCC is the greenhouse gas,
carbon dioxide with a set GWP of one. The values provided by GWP provide room for
comparison of effects emission has to the environment and limitation of the various gases.
The value of GWP is determined based on three major factors;
 Infrared radiation absorbed by the gases
 The lifespan of the gas in the atmosphere and
 The wavelength or electromagnetic spectrum at which the radiated gas is absorbed

There is a lot of focus given to CO2 since the gas has significant impacts on the environment as a
greenhouse gas. Also CO2 has much global warming properties.
Part c
310kg-280kg=30kg
30kg is equivalent to 80 years
80kg=80x80/30=310.3kg.
310kg=1kg of CO2
310.3kgx1/310
=2.67kg.
Question 3
Part a
35% OF 600TW-hrs=210 TW-hrs
1TW-hrs= 1000MW-hrs
210 TW-hrsx1000000
210,000 000Turbines
Part b
210,000 000Turbines X1000
=2.1X1011 Kw

It is given that 1KW=1000m2; 2.1X1011 Kw X 1000
=2.1X1014 m2 of land will be required for the project. This translates to =2.1X108 Km2 of land.
Part c
20 % OF 600TW-hrs=120 TW-hrs
1TW-hrs= 1000MW-hrs
120TW-hrsx1000000
120,000 000Turbines
Part d
120,000 000Turbines X1000
=1.2X1011 Kw
It is given that 1KW=1000m2; 1.2X1011 Kw X 1000
=1.2X1014 m2 of land will be required for the project. This translates to =1.2 X108 Km2 of land.
Part e
Available piece of land as 350000Km2 cannot support such kind of the projects.

REFERENCES
Alkama, R., & Cescatti, A. (2016). Biophysical climate impacts of recent changes in global
forest cover. Science, 351(6273), 600-604.
Bulkeley, H., & Newell, P. (2015). Governing climate change. Routledge.
Creutzig, F., Agoston, P., Goldschmidt, J. C., Luderer, G., Nemet, G., & Pietzcker, R. C. (2017).
The underestimated potential of solar energy to mitigate climate change. Nature Energy, 2(9),
17140.
Harvey, L. D. (2016). Climate and global environmental change. Routledge.
Hu, A., Levis, S., Meehl, G. A., Han, W., Washington, W. M., Oleson, K. W., ... & Strand, W.
G. (2016). Impact of solar panels on global climate. Nature Climate Change, 6(3), 290.
Kazimierski, L. D., Kuperman, M. N., Wio, H. S., & Abramson, G. (2018). Waves of seed
propagation induced by delayed animal dispersion. Journal of theoretical biology, 436, 1-7.
Najafi, M. R., Zwiers, F. W., & Gillett, N. P. (2015). Attribution of Arctic temperature change to
greenhouse-gas and aerosol influences. Nature Climate Change, 5(3), 246.
Pecl, G. T., Araújo, M. B., Bell, J. D., Blanchard, J., Bonebrake, T. C., Chen, I. C., & Falconi, L.
(2017). Biodiversity redistribution under climate change: Impacts on ecosystems and human
well-being. Science, 355(6332), eaai9214.
Sands, A. F., Apanaskevich, D. A., Matthee, S., Horak, I. G., Harrison, A., Karim, S., &
Matthee, C. A. (2017). Effects of tectonics and large scale climatic changes on the evolutionary
history of Hyalomma ticks. Molecular phylogenetics and evolution, 114, 153-165.