Earth's resources are finite

Abstract

Discussions on the future availability of both fossil fuel energy and minerals important to modern economies are sharply polarised. There are those who see limits approaching for fossil fuel use and minerals availability, as well as for ecosystem services such as fresh water and pollution absorption capacity provided at no cost by nature. This view was most famously put forward in the 1972 book 'Limits to Growth' by Donella Meadows and colleagues, but there are many more recent exponents of this view. Already, we may have exceeded safe limits for greenhouse gas emissions, loss of biodiversity, and disturbance of the nitrogen and phosphorus cycles, and may be approaching safe limits for a number of other environmental problems. A competing view is that limits to provision of fuels, minerals, etc can be circumvented by technological ingenuity. Non-conventional fossil fuels can replace depleted conventional fossil fuels if the need arises; mining progressively lower-grade ores, together with substitution and recycling of used products can solve possible raw material shortages; and new non-carbon energy sources, carbon capture and sequestration, and ultimately geoengineering, can mitigate any effects of global climate change. In this chapter we present material which can help resolve this dispute. We use the 'Earth Systems Science' approach discussed in Chapter 1. An underlying assumption of much human activity is that resources are either effectively unlimited, or that substitutes are readily available. We stress the energy costs of both energy and mineral extraction, and the interactions that can occur, for example, between the biosphere and the climate system. Also, all resources occur in individual nation states; these countries will not necessarily want to export increasingly scarce resources. Declining availability will place further difficulties in the path of continued growth in economic output, and, increase the likelihood of conflict over vital resources. This declining availability of useable resources, will also impact on our ability to provide food and fresh water to a growing human population. Increasingly in the future, if we continue in a 'business-as-usual' manner, we will face multiple interacting crises. Rising populations will need more food and forage for domestic animals at the same time as farmland and fresh water are lost to cities. In many low-income countries, output per hectare is already falling because of soil erosion. On-going climate change will further tend to lower agricultural output, because of high temperatures during the growing season, and probable rises in the frequency of pest outbreaks.