Absolute Masters

“... arborum autem consectione omnique materia et culta et silvestri partiam ad calficiendum corpus igni adhibito et ad mitigandum cibum utimur, partim ad aedificandum ut tectis saepti frigora caloresque pellamus. magnos vero usus adfert ad navigia facienda, quorum cursibus subpeditantur omnes undique ad vitam copiae … Terrenorum item commodorum omnis est in homine dominatus.”¹

“We cut down trees, and use every kind of wild and cultivated timber, not only to make fire to warm us and dress our meat, but also for building, and that we may have houses to defend us from the heat and cold. With timber likewise we build ships, which bring us from all parts every commodity of life. ... We are the absolute masters of what the earth produces.”²

Cicero, De Natura Deorum (On the Nature of the Gods), (45 CE).

          The heavy ax balanced by the trunk of the maple tree. The craggy branches stretched out in all directions like the veins in the wood cutter's sweat-drenched hands. The cool spring air had given way to the hot Mediterranean summer; the ocean breeze and the shade of the tree the only respite from the mid-day sun. It was a shame that by the evening, one of those things would be gone, but this was the last of Appius' work for now.

          The gnarled branches wouldn't be of much use, except for feeding the furnaces and the cooking fires of Silva, a sea-side colony that had been established some fifty years previous when the growing Empire first decided that it required monumental buildings. Those construction projects needed wood, and lots of it. The seven hills of Rome had long since been stripped bare of any but private forests. Instead, wood had to be imported, and that meant far-flung forests needed to be cleared, trees turned into timber, and brought in by land and sea. New roads needed to be cut into the countryside, new ships built in Portus, and a new colony founded to support the wood cutting camps – all of this for the glory of the Roman Empire.

          Over the years the little town had grown as more people came to make a living chopping down trees, or milling the trunks into useable planks. In time, merchants brought in a few of the luxuries of civilized life. Not long behind them a wave of immigrants arrived to setup shops near the new Forum, along with a cavernous bath house, aromatic bakeries, gilded theaters, and all the other trappings that marked a true Roman town. Towering apartment blocks were the first buildings to replace the tents and hovels around the piers. Then houses with high garden walls began stretching out from the roads leading to the Forum, and on the front of the houses more little shops opened. Before long, shrines to all the gods dotted the street-sides, and even more extravagant homes were built near the theater and baths. By the time the wood cutter was born, the town was already quite large: there was no way that one could meet every person that lived there. The cobblestone streets stretched into the hills.
          Merchants and shop owners came and went, temples relocated from time to time, and industrious individuals established all manners of workhouses with varying success. Throughout his entire childhood, the only constant thing was the rattle of the wood cutters carts down the main boulevard. Sometimes they would take a load of firewood to the warehouse where shop owners would go and haggle over the price. Other times the carts would go to the mill where the trunks could be split and hewed into boards, before being sent out on the road to Rome. Sometimes, on those rare occasions, a particularly massive tree would be dragged through town, several teams of oxen straining with all their might. Down to the pier they would go. The master of the docks would round up as many strong-backed laborers as he could find, and with a great effort, they would shift the tree off the cart and onto the waiting deck of a ship.
          Those were the most precious logs the town could produce, for they were destined to be used by the master architects in Rome for the most wonderfully impossible construction projects. Every now and then, the architects would send one of their assistants out to the colony to scout for the perfect tree for some specific joint or beam. The shipbuilders in Portus would do the same. When they were successful, it was the best of times. A high price would be paid for such a prize and the money would flow through the economic veins of the city. In the end, everyone was reliant on the bounty the forest provided. All things change in time.

          It was only shortly after Appius had become a man and decided to take up his father's profession, felling trees, that the shortages began. The Imperially decreed logging had taken all of the largest, and most suitable trees from the immediate area around the town. It could take days of traipsing through the woods before the architects' assistants would find a usable tree. The forward timber camps moved farther from the port each year, and it became more difficult to keep bringing firewood back for the wood sellers. As the town grew and filled in with industries, the demand for firewood grew as well. The town's overseer hired a new batch of wood cutters to clear out any of the trees Rome couldn't use to keep a supply of firewood coming in to the town's industrial heart. Realizing the price was rising for the wood needed to keep the bathwater hot enough for cosmopolitan tastes, the bath owner organized several of the local shop owners and hired another group of wood cutters to privately supply them with a stock. Descending like locusts on a field, the small armies of wood cutters thinned the forest quickly.

          From where Appius stood atop one of the higher hills in the ridge line, he could make out the rocky outcroppings just before the sparkling azure sea, which marked the furthest point inland visible from Silva's Forum. Farmers had tried to plant crops there, but each year the rains would wash away more of the fertile soil. Year by year, the once forested land changed into a green meadow, and the meadow into a less hospitable place full of patchy stands of wheat. When the rains came the mudslides started.

          Wide gaping wounds opened on the hill, weeping blacks, grays, and browns of topsoil, rocks, and dirt. It all came tumbling down, and was washed into the harbor. The once pristine country port took on a bleak visage. Plans were made to replant the forest to stabilize the hillside, but the saplings could scarcely put down a root before the spring rains would wash them away. Sacrifices were made to all the appropriate gods, and many animals were slaughtered over the issue, but it mattered little. The hillside had become barren.

          The town, now ten thousand strong, had an unquenchable thirst for the sap of trees. Beyond the fires for the hot baths, the potters' kilns, the bakers' ovens, and the glass blowers' furnaces, each house would draw in a quarter of a cord of wood per month for the warming fires in their homes, and the preparation of their daily meals. Before each new moon, 25 trees would fall for each house. Every year half a million trees would be split, stacked, dried, and sold in the public market. Before beginning their work, even the firewood collectors would spend two days traveling just to reach the receding edge of the forest. Every scouting trip for Rome's construction would find another emptied valley, and another hill weeping for the lost trees.

          This too would change. Plans for another awe-inspiring building in the capital had been announced, and two new colonies had been decreed by Rome. “It is no longer in Caeser's interest to continue harvesting at Silva,” the messenger had reported. Appius wondered how many empires Rome would need just to supply itself. Certainly, two new logging colonies today would not be enough; they would need three or four more after those were used up as well.

          Turning to pick up his ax, his back toward the decimated countryside, he faced the last tree in Silva of which he would be the absolute master.

A Note of Explanation to the Reader

           While this short story is fictional, it is inspired by two real-world things, the historical deforestation of Rome, a recurring issue during the Imperial period, and the modern energy use of a test group at the University of Arizona. The use of wood in the story was based on the modern energy use, which is not historically accurate. This is done with a bit of artistic license as a way to visualize the modern impact our energy use is having on the environment. To represent energy consumption, I used a native tree of Italy to stand in the place of modern energy generation. The Italian Maple has a recoverable heat value per cord of dry wood of 21.6 million BTUs.³

          Using the US Department of Energy's statistics on household appliances, each member of the test group's energy usage was estimated to be 753.6 kWh, 3,357 kWh, 10,360 kWh, 41,420 kWh, totaling 55,890 kWh/year, for an average usage of 13,970 kWh/year.⁴

Using: E(BTU) = 3412.14163312794 × E(kWh), to convert the kWh into BTU, 3412.14163312794 × 13,970 kWh/year = 47,680,000 BTU/year.⁵

          47.68 million BTU/year average energy usage / 21.6 million BTU per cord of Italian Maple = 2.207 cords of Italian Maple per person would be needed to generate the test group's average energy usage. Assuming one cord of wood per mature Italian Maple (known to reach sizes larger than 4 m in circumference and 17 m tall), and 50 trees per cord for a young forest, with no restraints on clear-cutting, I estimated an average of 25 trees per cord.^{6, 7}

          The fictional town of Silva, meaning “forest” in Latin, with 10,000 residents, was established as an early Imperial timber colony to supply Rome's growing demand for wood. At the time of the story, it has grown into a fully functioning Roman town with a robust and diverse economy and industry. As such, the total number of trees necessary for the population's personal use is 551,900 trees per year (2.207 cords per year per person x 25 trees per cord x 10,000 residents). The industrial and construction use of wood is alluded to, but not calculated.

          In addition to that, the test group's carbon footprint was estimated using two different online calculators (WWF International, and Global Footprint Network), on three continents (North America, Europe and Asia), and the results averaged.^{8, 9} The overall consumption rate for the group was 3.7 planets and the data ranged from 1.8 to 5.6 planets. This is expressed in terms of colonies that would be needed to replace Silva.

Figure 1 shows the estimated yearly energy use of a test group of students at the University of Arizona. The lowest energy requirements were from students living in the dorms, while the highest was from students living in houses, and it represents the impact of natural gas heating, and larger household appliances.

Figure 2 shows the distribution of results from calculating the test group's footprint on the Earth. When compared to Figure 1, very little similarity between personal energy use and overall calculated impact can be seen. While it is a factor used in both calculators, the large difference between the dorm-dwelling Subject 1 and the house-dwelling Subject 4, which is clear in Figure 1, is not evident here. This was mainly due to differences in travel habits of Subjects 1 and 2 as compared to Subjects 3 and 4. The latter two subjects live year-round in houses in the Tucson metro area, while the former pair live part of the year in the dorms and travel to their out-of-town homes several times per year. Subject 2 travels mainly by car. Although Subject 1 is generally our most energy conscious member, using nearly no electronic devices except a mini-fridge, the subject flies frequently. Subject 4 resides in a 64 year-old house with poor insulation, and uses a full stock of slightly dated household appliances, but rarely travels outside the city. So, the relative impact of air travel in this case nearly balances the two carbon footprints.

Figure 3 shows the number of trees each member of the test group would need to cut down and burn in order to generate their current usage. While this is essentially the same information as in Figure 1, it may be difficult to visualize a kWh, or even a BTU, but it is assumed that most people are acquainted with trees. It should be noted that due to the amount of rejected energy in the form of waste heat generated from burning a tree, the total number of trees needed would be much higher than this if they were uses in electricity generation.¹⁰ This is only intended as a representation of current energy use impact, and is not a recommended alternative power source.

Bibliography

Cicero, Marcus Tullius. Cicero in Twenty-Eight Volumes: De Natura Deorum; Academica. Vol. 18. Translated by H. Rackham. Ed. E.H. Warmington. Cambridge: The Loeb Classical Library / Harvard University Press, 1933. Available from The Internet Archive. Toronto: University of Toronto Libraries. https://archive.org/details/denaturadeorumac00ciceuoft.

– Cicero's Tusculan Disputations; Also, Treatises on The Nature of the Gods, and on The Commonwealth. Translated by C.D. Yonge. New York: Harper & Brothers Publishers, 1877. Available from Google Books. http://books.google.com/books?id=OVk_kzKZkU4C&pg=PA313.

“Estimating Appliance and Home Electronic Energy Use”. US Department of Energy, accessed March 5, 2014. http://www.energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-use.

“Estimating Firewood from Standing Trees”. University of New Hampshire Cooperative Extension, January 2005. http://ucanr.edu/sites/placernevadasmallfarms/files/76320.pdf.

“Estimated U.S. Energy Use in 2012: ~95.1 Quads”. Chart. Lawrence Livermore National Laboratory, accessed March 5, 2014. http://cdn.arstechnica.net/wp-content/uploads/2013/07/28210_2012_flow_chart_high_res.jpg.

“Footprint Calculator”. Global Footprint Network, accessed March 5, 2014. http://www.footprintnetwork.org/en/index.php/gfn/page/calculators/.

“kWh to BTU Conversion”. RapidTable.com, accessed March 5, 2014. http://www.rapidtables.com/convert/energy/kWh_to_BTU.htm.

“Measure Your Impact”. WWF International, accessed March 5, 2014. http://wwf.panda.org/how_you_can_help/live_green/footprint_calculator/.

“The Thickest, Tallest, and Oldest Italian Maple Trees (Acer Opolus)”. Monumental Trees, accessed March 5, 2014. http://www.monumentaltrees.com/en/trees/aceropalus/records/.

“Wood and Combustion Heat Values”. The Engineering ToolBox. Accessed March 5, 2014. http://www.engineeringtoolbox.com/wood-combustion-heat-d_372.html.

Notes

1  Marcus Tullius Cicero, Cicero in Twenty-Eight Volumes: De Natura Deorum; Academica, Vol. 18, translated by H. Rackham, Ed. E.H. Warmington, (Cambridge: The Loeb Classical Library / Harvard University Press, 1933), available from The Internet Archive, (Toronto: University of Toronto Libraries), https://archive.org/details/denaturadeorumac00ciceuoft, pg. 268-71.

It is worth noting that in the body of the story I have used the Yonge translation, which most closely aligns with current vernacular English; however, it is a slightly loose translation in my limited experience with Latin. This book offers the following more literal translation: “we cut up a multitude of trees both wild and cultivated for timber which we employ partly by setting fire to it to warm our bodies and cook our food, partly for building so as to shelter ourselves with houses and banish heat and cold. Timber moreover is of great value for constructing ships, whose voyages supply an abundance of sustenance of all sorts from all parts of the earth. … Likewise the entire command of the commodities produced on land is vested in mankind.”

2  Marcus Tullius Cicero, Cicero's Tusculan Disputations; Also, Treatises on The Nature of the Gods, and on The Commonwealth, translated by C.D. Yonge, (New York: Harper & Brothers Publishers, 1877), available from Google Books, http://books.google.com/books?id=OVk_kzKZkU4C&pg=PA313, pg. 313.

3  “Wood and Combustion Heat Values”, The Engineering ToolBox, accessed March 5, 2014, http://www.engineeringtoolbox.com/wood-combustion-heat-d_372.html.

4  “Estimating Appliance and Home Electronic Energy Use,” US Department of Energy, accessed March 5, 2014, http://www.energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-use.

5  “kWh to BTU Conversion”, RapidTable.com, accessed March 5, 2014, http://www.rapidtables.com/convert/energy/kWh_to_BTU.htm.

6  “The Thickest, Tallest, and Oldest Italian Maple Trees (Acer Opolus)”, Monumental Trees, accessed March 5, 2014, http://www.monumentaltrees.com/en/trees/aceropalus/records/.

7  “Estimating Firewood from Standing Trees”, University of New Hampshire Cooperative Extension, January 2005, http://ucanr.edu/sites/placernevadasmallfarms/files/76320.pdf.

8  “Measure Your Impact”, WWF International, accessed March 5, 2014, http://wwf.panda.org/how_you_can_help/live_green/footprint_calculator/.

9  “Footprint Calculator”, Global Footprint Network, accessed March 5, 2014, http://www.footprintnetwork.org/en/index.php/gfn/page/calculators/.

10  “Estimated U.S. Energy Use in 2012: ~95.1 Quads”, chart, Lawrence Livermore National Laboratory, accessed March 5, 2014, http://cdn.arstechnica.net/wp-content/uploads/2013/07/28210_2012_flow_chart_high_res.jpg