Entropy – an unauthorised biography
The energetic formative years
In the past, I have proven quite fond of mentioning both the Second Law of Thermodynamics and the concept of Entropy. However, I suspect that my doing so may have left quite a few people a bit cold… For those that know what I mean that was a pretty lame joke. For those that do not, let’s just say that our problem with energy is that there is only a finite amount of it in the Universe; and trying to stop it being converted into progressively less useful forms is like trying to prevent water flowing to the sea. Leaving aside the questions of how or why, the Universe appears to have had a beginning; and it appears to be perpetually expanding towards a dark state where everything reaches a uniform minimum temperature (i.e. so called Heat Death). Here too, it seems to me, the Second Law of Thermodynamics appears to be in danger of failing but, hey, take it up with the experts…
On Monday, I highlighted the fact that the Earth receives an enormous amount of energy from the Sun. Then, on Wednesday, I highlighted how fortunate we are that plants convert this energy into sugar, which forms the basis of all food chains on the planet. This is why fossil fuels are sometimes described as fossilised sunlight – with coal being derived from dead plants and oil; and gas being derived (predominantly) from dead sea creatures. As such, fossil fuels appear to violate the entropic principle, which dictates that things go from order to disorder (i.e. low entropy to high entropy). However, even though they take millions of years to be created, fossil fuels defiance of entropy can only be temporary; and they can only be burnt once. Thus, they contain an enormous amount of energy captured from the Sun and packaged into a very condensed form over unimaginably long periods of time. However, we are no more likely to come up with a method of doing this artificially than we are likely to genetically modify cells in the human body so that they can extract energy from sunlight.
In short, we are currently burning fossil fuels many times faster than they are being created, which is polluting our environment: The burning of fossilised carbon adds carbon dioxide into the atmosphere and oceans many times faster than it can be removed. We have known for decades that this would almost certainly cause problems but, for a variety of reasons, we have done very little to prevent those problems now becoming a reality.
A life of Dissipation
The Second Law of Thermodynamics tells us that energy cannot be created or destroyed; it can only be changed from one form to another. The only thing that appears to contravene this Law is the creation of the Universe itself. The Sun is not creating any energy; it is just a giant nuclear fusion reactor taking advantage of the fact that E=mc2.
The principle of Entropy implies that Energy is generally transformed from more to less useful forms. The formation of fossil fuels may appear to contravene this principle; but only when you look at them and the Carbon Cycle (as it is on Earth) in isolation. When you consider the journey that the Universe is on – from the Big Bang to its ultimate Heat Death – this act of defiance is only temporary. Therefore, just as it would seem unwise to deny that fossil fuels are a non-renewable source of energy that will run out one day, I think it is unwise for anyone to pick a fight with the way the Universe works.
However, our greatest problem is not that the Universe may well be on a one-way entropic journey to a cold dark future state of nothingness; it is that fossil fuels are going to run out much faster than the fusion reaction in the Sun. Furthermore, just as the Earth will become uninhabitable long before the Sun runs out of fusion energy to dissipate; so the Earth will become uninhabitable long before we humans run out of fossil fuels to burn. That being the case, I think we should stop doing it: Relying on the Sun (for heat, light, and – albeit indirectly – winds and waves) would seem like the better option; and don’t forget all that geothermal energy beneath our feet as well. Speaking of which, entropy dictates that it must all escape eventually but not in any timescale relevant to us; and – in the meantime – it is a shame to let it go to waste.
The inevitable conclusion
The post-carbon era is coming; and we cannot stop it: The only question that remains is are we going to embrace that future; or cling to the past? One thing is for certain; both choices have consequences: If we plan for a sustainable future then we have a chance of making an organised transition to it. However, if we do not plan for it, it will still arrive; and it is unlikely to be pleasant.
Here are two videos from the Post Carbon Institute (PCI) that are well worth watching (depending on the time you have available to ponder these issues).
A 300-year history of fossil fuels use told in about 300 seconds (narrated by Richard Heinberg – as in the PCI’s excellent ‘Addicted to Growth’ video):
A 30-minute video on the consequences (both good and bad) of our comparatively recent access to cheap energy (narrated by Peter Coyote):
A more positive post-script
People say that nothing lasts forever and, certainly, that applies to fossil fuels. They may have taken 300 million years to form but, from start to finish, we humans will have burnt them all in little more than 300 years. That means we will have burnt them 1 million times faster than they took to form; a definition of unsustainable development if ever there was one.
However, the post-Carbon era may well be inevitable but it does not have to be dark. It could be very bright indeed; all we need to do create a star here on Earth (see video embedded below): If we can build a nuclear fusion reactor that does not consume more energy than it produces, our energy problems will be effectively over.
Thanks to E= mc2, the mass converted to energy in an atomic bomb explosion is approximately 1 gram. Compare this to the nuclear fusion reaction going on in the Sun. Because the Sun is so massive, it can burn for billions of years by converting 4 million tonnes of mass to energy every second – equivalent to 4 million million (4 x 1012) atomic bomb blasts per second. Almost incredible; but true nonetheless.
Scientists are working on this right now but, it will take time to make it work – and time is a luxury we no longer have. Even though we may have to continue to use hydrocarbons to make plastics and to fly our aeroplanes, we must substitute their use where ever we can; and minimise our use of them because once they are gone they are gone. We cannot manufacture them in a laboratory; and even if we could… burning them would still be a problem. Basically:
If you think fossil fuels are the answer, you are asking the wrong question!