An unsustainable path

The sustained growth in global GDP undoubtedly reveals improvements achieved in financial comfort in many parts of the world. The global economy has grown from US$19,16 trillion in 1970 to US$85 trillion in 2019 (2010 constant prices) which equals more than a fourfold increase or double the rate of population growth[1]. Even though this metric presents clear limitations as far as generalised standards of living are concerned, less people live now in extreme poverty. Middle-income layers are on the rise in many countries. As a result of these improving conditions, global population more than doubled between 1970 and 2020 (3,7 to 7,8 billion, respectively).

Growth has come at a price though. Following the footsteps of Western countries’ trajectories, economic growth across the globe has brought new consumption habits, accompanied by increased pollution, loss of biodiversity and resource and environmental depletion.

Growth has demanded considerable resources. Primary energy usage has increased 10-fold (see Figure below). Global energy consumption stood at about 12 thousand Terawatts per hour in 1900 and about 158 thousand now. Most of it is primarily fossil fuels based (coal, oil and gas) which produce carbon dioxide and other greenhouse gases – one of the main culprits for global climate change. Global average per capita energy consumption has been consistently increasing; between 1970-2014, the average consumption increased by approximately 45 percent.

Global Direct Primary Energy Consumption
Figure. Global Direct Primary Energy Consumption, by source. Source: Vaclav Smil (2017) and BP Statistical Review of World Energy.

Water usage has increased six times since 1900. Freshwater withdrawals for agriculture, industry and municipal uses have increased constantly, even though at a lesser rate since 2000 (see Figure).

Global freshwater use over the long run
Figure. Global Freshwater use. Source: V Flörke et al. 2013; aus der Beek et al. 2010; Alcamo et al. 2003.

Global material consumption reached 90 billion Tons in 2017, up from 30 billion Tons in 1970. Over the last four decades, global material use has tripled, increasing on average 2,7% annually. This trend even accelerated in the first decade of the XXI century, reaching 3,7% annually (see Figure below), contrary to population and GDP trends. Two-thirds of all global raw materials are extracted solely for exports and expected to reach 150 billion metric Tons by 2050 (UNEP 2011).

Global material flow evolution
Figure. World Domestic material extraction, 1970-2017, by material group. Source: WU Vienna (2020): Material flows by material group, 1970-2017. Visualisation based upon the UN IRP Global Material Flows Database. Vienna University of Economics and Business. Online available at: materialflows.net/visualisation-centre

Recycling rates continue at extremely low rates. Despite recent efforts, plastic continues to be recycled at a marginal rate.  Current recycling rates are thought to be about 16% at the global level. The rest is either incinerated (24%) or disposed in landfill or the natural environment (60%). Conversely, metals and paper are thought to be recycling at about 50%[2].

The resource extraction / needs evolution highlighted above show the unsustainable path that we are currently treading. Right now, there is growing evidence that the planet is already passing its safe ecological limits and an increasingly dangerous number of biophysical systems are in jeopardy, with no region left unharmed.

While we are already experiencing signs of over-exploitation and scarcity we will also need to meet the needs of additional human beings – we are expected to reach 10 billion souls in 2050 (plateauing at that point) – with all associated needs in terms of energy, water, food and materials. For example, until 2050, food demand is expected to grow even further by at least 58%[3], energy by 45%[4] and water by 30%[5].

Global Energy consumption projection
Figure. World energy consumption quadrillion British thermal units. Source: US Energy Information Administration.

This linear model of extract-transform-dispose, based on low prices, increased processing and consumer demand sophistication is leading our ecological footprint to boil over Earth’s capacity.

But does this have to be like this?

Undoubtedly, market controls seem insufficient to regulate the model imbalances. For one, market players take little account, and sometimes benefit, from negative externalities (e.g. environmental, social) of their actions.

Secondly, nature provides fundamental functions, such atmospheric, hydrological and biological systems, whose absence would make it impossible for life to exist. Some of them are non-renewable (or unable to be replenished in a human’s lifetime), leading to public loss, as in climate change. They pass unnoticed in any economic evaluation.

Thirdly, mainstream policies and decision making have shown to be grossly outdated, based on wrong notions and beliefs in the abundance of natural resources. Vying for limitless growth and natural constraints, subsidies and incentives are still attributed to resource-intensive industries and distribution systems, and not towards economical living within Earth’s means.

Preventing catastrophic climate change until 2050 will not be achieved unless we fundamentally change our extract-produce-dispose model, the compartmentalized economic policies of the past, the underlying reasons policies are designed and the stakeholders involved in that implementation.

Earth is undoubtedly treading an unsustainable path, and new frameworks and policies, fit for a finite world, are needed. Given the latest signs, especially, regarding a changing climate, these policies are needed fast.


[1] UNEP (2016). Global Material Flows and Resource Productivity. Pp.31.

[2] OECD (2018). Background Report: Improving Plastics Management.

[3] HBR (2016). Global Demand for Food Is Rising. Can We Meet It?

[4] EIA (2019). “EIA projects nearly 50% increase in world energy usage by 2050, led by growth in Asia”

[5] Boretti, A., Rosa, L. Reassessing the projections of the World Water Development Report. npj Clean Water 2, 15 (2019). https://doi.org/10.1038/s41545-019-0039-9

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