Sound Science Bite: May 6. Why Should You Care about the Second Law of Thermodynamics?

Because it is either biting you now or will bite you soon, Big Time. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has just issued a dire report on the state of the natural world. Here is the link to the Summary for Policymakers. What does this have to do with the second law of thermodynamics? What is this law anyway?

There are numerous equivalent ways of stating the second law of thermodynamics. For present purposes: The creation of order at one location will produce a greater amount of disorder at another location. Nature (sans humans) is in tune with this law because it removes disorder in the form of heat while perserving order in its structure. The heat ultimately makes its way to outer space. This has worked for hundreds of millions of years. Humans also produce disorder in the form of heat (body heat and hot water from an electrical power plant, as examples), but we have yet to master the recycling of matter that nature does so well. We also have yet to master the equilibrium of human biomass. Natural biomass would be in equilibrium if we humans weren't expanding ours (and that of our crops and animal stock), while at the same time over fishing and claiming more and more land for our use (natural habitat destruction).

It's not hard to find disorder in matter from human activity. In fact, it often finds us as polluted air, water, land, and now there's discarded plastic everywhere, raising ever greater concerns about its environmental effects. Disorder has unintended consequences. Look at climate change due to greenhouse gas emission, for example. Our ignoring of the second law of thermodynamics will cost us dearly if we don't change course as a species, because we need a healthy natural world to exist if we are to survive ourselves. And, by the way. The second law of thermodynamics was not passed by a panel of liberal scientists.