Global Material Consumption
In 2015 global material consumption was an average of 12 tonnes of material for each person on Earth
Material Consumption: WU Vienna1
GDP: World Bank2
Population: World Bank3
Economic activity is usually measured in monetary units. But economic activity involves throughputs of matter and energy, thus the economy also has physical dimensions. 4. Economic activities involve the extraction of material resources and emissions of wastes, and these both generate environmental impacts.
The graph above shows the increasing annual global material extraction per person for every year since 1970. The graph below shows the total global extraction of materials, divided into four categories. In 2015 the global extraction of materials was 87.5 billion tonnes, or a staggering 11.98 tonnes per capita.
Economic growth tends to cause an increase in environmental impacts (Krugman and Wells, 2015: 708). Orthodox economics acknowledges assumes that economic growth can be sustained indefinitely. This requires either assuming that the size of the economy is far from any ecological limits, or that economic growth can be decoupled from growth in environmental impact. The two graphs show the difficulties of these assumptions. The physical quantity of resources used by an economy is a good indicator of environmental impact (Hickel and Kallis, 2018: 1). The physical size of the global economy is vast, and this inevitably generates significant consequences for the environment.
The environmental impact of economic activity can be modelled using the Ehrlich equation, which can be simply written as:
I = P x A x T
where I is impact, P is population, A is affluence, and T is the technological intensity of output.
If environmental impacts are not to increase, then increases in any of the three factors must be offset by decreases in another. The concept of ‘green growth’ implies that GDP growth and environmental impacts can be decoupled, and the economy can grow without an increase in environmental impacts. This means that if environmental impacts are not to increase technological intensity (T) must fall faster than the GDP grows (P x A).
As the top graph shows, material consumption per $ of global GDP, or the ‘material intensity’ of the economy has fallen by about 14% since 1970. However this has been far from sufficient to offset the growth in population and affluence which led to the world economy quadrupling in size over the same period.
- WU Vienna, ‘Domestic Extraction of World in 1970-2017’, The Material Flows Analysis Portal (WU Vienna, 2019) http://www.materialflows.net/visualisation-centre/ [accessed 23 February 2020]
- World Bank, ‘World Bank Open Data: GDP (Constant 2010 US$)’ (The World Bank) https://data.worldbank.org/indicator/NY.GDP.MKTP.KD [accessed 23 February 2020]
- World Bank, ‘World Bank Open Data: Population, Total’ (The World Bank, 2019) https://data.worldbank.org/indicator/SP.POP.TOTL [accessed 11 July 2019]
- Daly, Herman, Beyond Growth: The Economics of Sustainable Development (Boston, Mass.: Beacon Press, 1996) p.47