Cassandra has moved. Ugo Bardi publishes now on a new site called "The Seneca Effect."

Thursday, May 31, 2018

Turning Trees Into Enemies. The New War on Forests

The San Marco Square in Florence in 2017. You can see the ancient trees of the square being cut as part of a plan that involved the removal of several hundred trees in the whole city. The action was accompanied by a propaganda campaign against trees that looked curiously similar to that used to justify the invasion of Iraq, in 2003. "Trees are a threat to citizens,", "There is no alternative," "Killer Trees," and the like.

The war on trees seems to be starting. I don't know about what's happening where you live, but here, in Italy, we see it clearly, accompanied by all the propaganda tricks normally used to start wars. So, we have seen a string of accusations in the media against "killer trees," supposed to be a danger for the citizens because they can fall on them or on their beloved shiny cars. The image on the right, here shows the first page of an Italian newspaper in 2014 informing us there are "50,000 killer trees" in Rome. Truly an invading army to be fought with the appropriate weaponry in the form of chainsaws.

One century ago, city administrations were proud of planting trees, today they are proud of cutting them. What happened that changed their attitude so much is hard to say. Maybe it is the general degradation of the ecosystem that has turned trees into monsters, but that doesn't explain how administrations are starting also a war on forests - surely not threatening citizens or their cars. In a previous post, I commented on a recent piece of legislation in Italy that forces land owners to cut their woods even if they don't want to. From the comments I received to that post and from what I can read on the Web, I think I can say that the war on trees is not just an Italian phenomenon, it is worldwide.

I interpreted this war as the result of the diminishing returns of our energy sources - mainly fossil fuels. The returns of an energy source, as you may know, can be expressed in terms of EROI (energy return on energy invested). It is the ratio of result to effort. Extracting oil, for instance, implies digging a well, using pumps, and many more things which have an energy cost. The energy obtained from oil need be much larger than the energy spent on oil, otherwise the whole effort would be useless. And, historically, it has been the case. At the height of the oil age, an oil well in the US provided perhaps 50 times the energy spent to extract the oil. But not anymore: it is the harsh law of the EROI: it declines with time. The consequence is a well-known law in economics: diminishing returns on investments.

What's happening worldwide is that the EROI of fossil fuels has been going down. It was expected: it is a result of the gradual depletion of the resources. Obviously people will look first for the best resources, then progressively move to less good ones. This has consequences: the worldwide search for oil and other fuels leads to conflicts for what's left - the invasion of Iraq in 2003 is a good example. But even the Iraqi oil is subjected to the harsh law of EROI. The result is that some energy resources which, once, looked old and outfashioned, now start looking good again. Wood, for instance.

And here is the reason for the war on trees. As all wars, it is a war on resources. And, as it is normal in our times, before going to war, you demonize your enemies - hence the "killer trees." It is also traditional to state that wars are done in the name of lofty and noble principles, in this case in the name of ecology, since wood is said to be a "carbon neutral" energy resource and therefore cutting trees somehow fights global warming.

Alas, no. Wood burning is NOT carbon neutral. It is true that the CO2 generated by burning biomass will eventually become biomass again, but it takes time. A recent study estimates that it takes several decades, even a century, for the CO2 generated by burning trees to be reabsorbed from the atmosphere in the form of new trees. And that assumes that the forest reforms while, in practice, forest razing is often an irreversible phenomenon, at least on the century time scale. According to some recent studies, the Sahara may be a human-made desert.

So, the harsh law of the EROI holds also for wood. If the current rush to wood cutting continues, the best resources will soon be exhausted and cutters will move to more expensive ones. At some moment, the cycle that's leading from fossils to wood will repeat itself: after wood, what? How about burning furniture?


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)