The Human Factor: Demographics and Social Trends

Session 07

ES/SO352 Sustainability - Session 07

Required readings:



  • Review final papers (reports from their actions designed and implemented) from previous semesters.
  • Start Action Plan pages, related to the Final paper in groups, at the course website
  • Learn some (maybe new?) concepts:
    • "ecological footprint", and the meaning of its units. Learn the difference with the Carbon or Water footprints.
    • "carrying capacity" of a system (like the Earth)
    • the impact of population size in world environmental problems

How many are we?

Population size

Spatial heterogeneity:

  • Population distribution
  • Resources
  • Economic development (=different needs)

How many are we going to be?

We all contribute to population growth!

Pending questions

  • How much are we going to need? (food and resources to sustain life)
  • How much waste (as non-nutrient) are we going to produce?
  • How much of us is the Earth able to sustain?

... it depends on a series of factors... (see next slides)

World population, consumption and carrying capacity

  • This video looks at the global population and trends. It also explains the concept of carrying capacity and how a person's behavior influences carrying capacity.
  • Carrying capacity:
    The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment.

Ecological footprint

  • A description of the ecological footprint and its limitation. It goes into some depth on the computation on the footprint and what it means for the global population.

Ecological Footprint (ii)

  • amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to assimilate associated waste, from cradle to grave.
  • measured in gHa per capita: "Global Hectare per person"
    • amount of biologically productive land and water available per person on the planet.
Example: in 2005 there were 13.4 billion hectares of biologically productive land and water available and 6.5 billion people on the planet. This is an average of 2.1 global hectares per person. Due to rapid population growth, this figure is decreasing.
HDI: The Human Development Index is the normalized measure of life expectancy, literacy, education, standard of living, and GDP per capita for countries worldwide

Ecological Footprint (iii)

Ecological Footprint (iv)

Source: 2007. UNEP. Global Environmental Outlook http://www.unep.org/geo/geo4.asp

Ecological Footprint (v): Animation

  • A sight to what is ecological footprint and some easy ways to reduce the own ecological footprint.

Carbon footprint

  • Carbon Footprint: A measure of the total amount of carbon dioxide (CO 2) and methane (CH 4) emissions of a defined population, system or activity, considering all relevant sources, sinks and storage within the spatial and temporal boundary of the population, system or activity of interest.
    • Wright, L.; Kemp, S., Williams, I. (2011). "'Carbon footprinting': towards a universally accepted definition". Carbon Management 2 (1):61–72

Water footprint calculations

  • Water footprint: the total volume of freshwater used to produce the goods and services consumed by the individual or community or produced by the business.

How to change our Global Ecological Footprint =

= Population SIZE + Change of HABITS + New TECHNOLOGY + Infrastructure (RE)DESIGN

TEDx Talk: Our Big Bang the need for a Great Transition: Stewart Wallis (22:15')

    • Stewart Wallis joined nef (the new economics foundation) as Executive Director in 2003. His interests include global governance, functioning of markets, links between development and environmental agendas, the future of capitalism and the moral economy.
      He spent seven years with the World Bank in Washington DC working on industrial and financial development in East Asia. Stewart joined Oxfam in 1992 as International Director with responsibility, latterly, for 2500 staff in 70 countries and for all Oxfam's policy, research, development and emergency work worldwide. He was awarded the OBE for services to Oxfam in 2002.

Other interesting readings:

  • Ehrlich PR (2010) The MAHB, the Culture Gap, and Some Really Inconvenient Truths. PLoS Biol 8(4):e1000330. doi:10.1371/journal.pbio.1000330. Available online at: http://www.plosbiology.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.pbio.1000330&representation=PDF
  • Galli, A.; Halle, M. Mounting Debt in a World in Overshoot: An Analysis of the Link between the Mediterranean Region’s Economic and Ecological Crises. Resources 2014, 3, 383-394. Available online at: http://www.mdpi.com/2079-9276/3/2/383/pdf
    • During the period of 1961–2008, demand for renewable resources and ecological services (as measured through the Ecological Footprint methodology) in the Mediterranean region grew by 52% (from 2.06 to 3.12 global hectares per capita), while availability of such resources and services (or biocapacity (BC)) decreased by 16% (from 1.49 to 1.26 global hectares per capita). As all economic activities ultimately depend on ecological assets—such as productive land and marine areas, and the services and resources they produce—this paper presents a reflection on the economic implications of such resource and service overconsumption in the Mediterranean region. Our conclusion is that, in a world characterized by the existence of biophysical limits, risks may exist for Mediterranean economies due to the concurrence of: (1) resource scarcity; (2) increasing resource prices; and (3) challenging national economic situations.

Other videos

  • Human population growth
    • This video address the specifics of why and how human population growth has happened over the past hundred and fifty years or so, and how those specifics relate to ecology. Define the main concepts of the session (ecological footprint, carrying capacity...)

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