Ban Ki-moon has been quoted saying “We are using resources as if we had two planets, not one. There can be no ‘plan B’ because there is no ‘planet B”¹. Each year, we consume more resources depleting our planet so much so that we have started tracking when this “overshoot” takes place. For example, in 2016 demand for ecological resources and services exceeded what our ecosystems can regenerate in that year on 8 August². It is important to note that the “Earth Overshoot Day ” is being consistently brought forward – it was on 18 August in 2014³.
Our planet’s finite resources and the rate at which we are depleting them has led to a lot of debate about the efficient use of our planet’s natural wealth as well as the type of resources that we should prefer in order to limit the impact that we are having on our planet. A key distinction in terms of the resources that are at our disposal is whether they are renewable or non-renewable. Renewable resources are resources that can or will be replenished naturally in the course of time so the rate at which we are using them does not affect their availability. In contrast, non-renewable resources are those that are available to this planet in limited quantities or those that are renewed so slowly that the rate at which they are consumed means that on balance their stock is being depleted.
Let’s explore some examples of renewable and non-renewable resources
Timber: our trees are considered a renewable bio-based resource. The reason being that trees can be planted, grown, trimmed and taken down and then more trees can be replanted in their place. Trees provide a most precious raw material: timber is used to make paper and paper products but also has a whole host of other uses such as a building material, for making furniture or other everyday objects from cooking utensils to decorative ornaments.
Peat: peat, commonly found in the UK, Ireland or Finland, is a soft organic material consisting of partly decayed plant matter together with deposited minerals⁴. Peat can be dried out and used as fuel but it is also an important raw material in horticulture and for potting. Some peat industry representatives and academics believe that peat is a slowly renewable resource but in reality a peat bog takes thousands and thousands of years to form. So if one considers the rate at which peat is being used either for energy or as a growing medium, then it is evident that it is not a renewable resource. Peat bogs are considered such important parts of our ecosystems that in most countries they are protected or considered conservation areas.
Water: one of the most important resources of our planet; life without it would be impossible on Earth. What is even more extraordinary is that more than 99% of Earth’s water is unusable by humans or cannot be used to grow plants⁵. But water is not a renewable resource – it cannot be replenished in the same way that trees can be replanted. Instead, it follows what scientists call the water cycle whereby water evaporates from the Earth’s surface only to come back down again in the form of rain or snow. At the same time, when it comes to our available water resources, we often pollute them to such an extent that we cannot reuse them.
Soil: by looking at the land around us, you would think that soil is pretty much inexhaustible. But the truth is that not only does it take centuries for natural processes to regenerated soil, but it is estimated that 33% of our land is moderately to highly degraded due to the erosion, salinization, compaction, acidification and chemical pollution of soils⁶. Having said that, it is possible to renew and replenish the nutrients in soil that make it fertile so that crops, plants and flowers can grow.
Air: the air we breathe is a renewable resource. It can be cleaned and replenished thanks to a number of natural processes, not least because of the crucial role that trees play in absorbing CO2 and releasing oxygen. But while the natural cycled would allow for air to be renewed, a lot of anthropogenic activities disrupt this cycle and pollute our air. So while there is no shortage of air, its quality particularly in many industrial and urban areas is very bad and often polluted to such an extent that it is bad for human health.
Sand: if you think that soil is an inexhaustible resource, then you would probably think the same of sand. According to UNEP, sand and gravel represent the highest volume of raw material used on earth after water. Their use greatly exceeds their natural renewal rates. This not hard to imagine if one considers that 40 billion metric tons of sand and gravel are extracted every year for the construction industry, glass manufacturing, and other uses such as land reclamation and oil exploration⁷.
Aluminium: another non-renewable resource, aluminium, is key for meeting a lot of our societal needs. From packaging to making parts for automobile or railway cars, aluminium is a versatile material. Even though aluminium is the most abundant metal on Earth, it is expensive to extract largely because of the amount of electricity used up in the process⁸.
Sun: today, with renewable technologies we can use solar power to meet our energy needs. Our use of solar energy does not deplete the sun in any way. As such, solar energy is a renewable form of energy. This is not to say that the Sun will survive for eternity. In fact, we know that Suns in all solar systems can die.
Oil: probably one of the most well-known non-renewable resources alongside coal. Oil is a non-renewable form of energy as it is a fossil fuel, having been made over thousands of years as plant and animal debris were covered with layers of soil and rock. Given that only in the US an average of about 19.4 million barrels of oil is consumed per day⁹, it is clear that we are using our oil reserves much faster compared to how fast nature can replenish these reserves.
Coal: another commonly used fossil fuel whose reserves are being increasingly depleted is coal. About half the electricity in the United States comes from coal¹⁰. But extracting it and using is not only highly polluting to the environment but it can also create health risks as coal miners are exposed to toxic dust.