1.5 Global Trends Over Time in Food, Water and Energy and Economics

Figure 1.5.1 Food Production with population growth 0 AD – 2020

Source: The Watchers [see reference 7]
Figure 1.5.1 sourced from The Watchers (Author: CHILLYMANJARO) under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
http://thewatchers.adorraeli.com/2011/10/13/feeding-the-world-solutions-for-a-cultivated-planet/

 
Every human requires land for their basic needs and a big proportion of this is agricultural land for their food. As population has increased so has food production, and similarly the pressures on land resources to provide the increasing demand for food. Strains are being shown not only in the amount of land used for food production, but also in the fertility and productivity of the soil. Sustainable food and engineering will be covered in Chapter 5.

Figure 1.5.2 Global water use by sector

Figure 1.5.2 sourced from The ImpEE Project, The Cambridge-MIT institute.
http://www-g.eng.cam.ac.uk/impee/?section=topics&topic=water&page=slideshow

Water demonstrates a similar pattern to food, but note the difference in time scales. Natural water systems are under pressure from overuse, pollution and impacts of climate change. Water supply will be covered in Chapter 4 in more detail; careful consideration must be given to this precious resource on which all life depends.

Figure 1.5.3 Global Energy Consumption since 1850

Energy will be covered in the next chapter, but note the start of the curve is around the time of the industrial revolution, when the stream engine was invented and fossil fuels became the main source of industrial energy. Energy use is linked to economic development, and in the current context, pollution and resource depletion: two key factors of unsustainability.

Figure 1.5.4 World GDP 1 AD -2000

(Source: visualising economics.com [see reference 10])
Figure 1.5.4 sourced from Visualizing Economics under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License
http://visualizingeconomics.com/cool-data/

The graph above shows the exponential increase in gross domestic product of the world, which is effectively a measure of wealth. Economic growth has been the central driving factor for the advancement of humanity and the negative environmental and social consequences or “externalities” that have resulted from it. It is a challenging subject to comprehend fully, but economics and its relevance and importance in an engineer’s role in understanding sustainability will be delved into in chapter 8.