How much can we take from our planet without harming it? Are we using more resources than we should? And if so, how can we start taking less to ensure both us and our planet thrive in the future? These are arguably the most important questions science needs to address in the Anthropocene. Focusing on the first two, a large team of scientists set out to identify the boundaries we need to prevent the Earth from becoming sick. What their results show, however, is that most of these boundaries have already been crossed.
The last 150 years have seen a much more rapid change in our lifestyle than humans have ever experienced 1. Over millions of years, stone tools hardly developed, but in only 66 years, we went from the first aeroplane in the sky to landing on the moon. These recent developments were only possible by exploiting the resources around us, but for progress to continue, we need to refrain from taking more than the Earth can give us. Scientists call the points where we must draw this line, ‘Earth System Boundaries’ (ESBs).
To determine where these boundaries lie, the scientists involved in this study had to consider multiple areas, including freshwater, nutrients and air pollution, on both a global and local scale. To understand this better, let’s visualise it! Imagine the planet as a scale, with humans on one side and the natural ecosystem on the other. Now, imagine the various resources of the Earth as the weights. Humans and nature can only be healthy if there is a perfect balance, and if this balance is broken, both suffer. Yet, like with a scale, some weights are heavier than others, meaning they need more consideration in the balancing act. However, the size of the weight representing each resource changes according to where it is in the world, depending on its value and abundance in the area. Therefore, both the global and local boundaries of any resource need to be considered to know how much we can use.
Scientists did this by bringing together the opinions of experts, knowledge of how the level of different resources fluctuates over time, and evidence of how humans and the ecosystem are affected when resources become too scarce. For example, intensive farming and deforestation take nutrients away from the soil, and over time this makes the land less able to produce food 2. Secondly, they checked if adhering to the boundaries they set would keep the Earth safe, with a particular focus on humans across different countries and generations. Lastly, having identified these boundaries, they looked at the current picture to see whether humans are respecting them or not.
This is when the story takes a dark turn. The scientists found that 7 out of the 8 ESBs that they identified have already been crossed, including those relating to our use of nitrogen, phosphorus, and both groundwater and surface water. However, as the study points out, people are not all equally responsible for the current situation. In fact, 86% of the human population, covering roughly half the planet, only transgresses 2-3 EBS, while 28% of the population (covering 5% of the planet) exceeds 4 or more. And even within these categories, there is great disparity. As a 2015 Oxfam report points out, the wealthiest 10% produce half of the global carbon emissions, while the poorest 50% only produces 10% 3.
What can we do to stay within the suggested ESBs then? If we consider Oxfam’s figures again, most European citizens would be in the remaining 40% of humans, which produce around 40% of emissions. This means that paying attention to our daily use of water or energy can add up to make a significant positive change. Nevertheless, we should be conscious of the inequality in carbon emissions. A single billionaire creates more emissions than a million average people 4, meaning that as much as we can work to improve our own carbon footprint, the most meaningful impact we can make is to press for a change among the top 10% through voting, speaking up, and supporting movements which try to hold this minority accountable for their damage.
Article by Maria Giulia Checchi
References
Source paper: Rockström J, Gupta J, Qin D, Lade SJ, Abrams JF, Andersen LS, Armstrong McKay DI, Bai X, Bala G, Bunn SE, Ciobanu D. Safe and just Earth system boundaries. Nature. 2023 6;619(7968):102-11.
- Easterlin, R.A. (2006). Growth triumphant: the twenty-first century in historical perspective (Univ. Of Michigan Press).
- Hartemink AE, Veldkamp T, Bai Z. Land cover change and soil fertility decline in tropical regions. Turkish Journal of Agriculture and Forestry. 2008;32(3):195-213.
- Oxfam (2015). World’s richest 10% produce half of carbon emissions while poorest 3.5 billion account for just a tenth. Oxfam International.
- Oxfam (2022). A billionaire emits a million times more greenhouse gases than the average person. Oxfam International.
