Sound Science Bite: April 4. The 15 March 2013 issue of the journal "Science" contains an article in its Perspectives section that discusses an often overlooked effect as humans consume more resources on a finite planet. You hear from time to time concerns about this consumption and how we need to moderate it until, at the least, consumption ceases to grow. The aim is to reduce environmental damage associated with this consumption. In this article, Debra Davidson and Jeffrey Andrews point out, however, that as resources become more and more scarce, environmental damage will grow even if consumption were held steady. In particular, as hydrocarbon fuels become more and more difficult to find and extract, enviromental damage will grow due to that extraction and to longer transport as fuel sources become more remote. Hence, not only does the growth of consumption degrade the environment, but the environmental cost of the consumption per unit extracted goes up as well. This problem applies equally to other resources, such as ores and arable land.
The conclusions of this article are strongly in accord with the second law of thermodynamics in physics, which says that in a closed system the amount of usable energy diminishes until it becomes zero. The Earth is not a closed system as far as energy is concerned, since we get energy from the Sun and radiate heat energy back to space due to the fact space is much colder than the Earth. (Heat flows from warm to cold.) However, this law applies to matter as well; for example recall the well-known statement that it is much easier to scramble an egg than to unscramble it. With respect to matter, the Earth is virtually a closed system. The second law says that without using energy (ultimately from renewable sources) to "unscramble" our eggs (that is, using recycling and reprocessing instead of one-time consumption), we will eventually have no eggs to scramble. All our former resources will be impossible to reclaim. For more on this read my article The Heat Death of Civilization..