The importance of local consumption
The importance of local consumption
All of nature is based on a complex system, but also with very simple logical principles, which make diversity, the fragmentation of roles (energetic, biological, etc.) and sharing the core.
Placing oneself outside the rules of nature is impossible, as well as inconvenient. Like mathematics, thermodynamics (branch of physics) is not an opinion.
Ecosystems, both natural and social (and their essential correlations) must be based not only on the three aforementioned principles but tend to, if no disturbing factors intervene (natural catastrophes, fires, sudden climate changes, floods, earthquakes, volcanic eruptions, etc.), to stabilize and organize themselves better (such as efficiency and resilience of the system) in cells communicating with each other. A bit, on a large scale, like what happens between the cells of a multicellular organism.
These cells (which at a planetary level are ecosystems, more or less large) tend to promote closed thermodynamic cycles* which offer significant energy efficiency advantages compared to open cycles.
The fluid of the thermodynamic system, which in an ecosystem is represented by the whole of the biotic and abiotic system and their biological and ecological interactions, derives notable advantages which, ultimately, increase its energy efficiency. Below, therefore, when we talk about fluid, we must mean the complex of actions, interactions and work carried out by individual organisms and the physical environment of an ecosystem.
Let’s analyze, in summary, the main benefits of closed thermodynamic systems:
– Improved energy efficiency: in closed cycles, the working fluid is continuously recirculated within the system. This allows you to optimize the operating conditions (temperature, pressure) of the fluid to maximize the efficiency of the cycle. Furthermore, energy losses are reduced since there is no dispersion of fluid (such as biodiversity) towards the outside.
– Control of operating conditions: In closed cycles, it is possible to precisely maintain and control the operating conditions of the working fluid. This allows optimal temperatures and pressures to be achieved which improve the thermal efficiency of the system.
– Lower environmental impact: since the working fluid is confined within the system and is not released into the environment, closed cycles tend to have a lower environmental impact.
– Heat recovery: in closed cycles, waste heat can be recovered and reused within the cycle, further improving overall energy efficiency (low entropy production). For example, waste heat can be used for other fluid processes as an input source.
– Working fluid versatility: Closed loops can use a wide range of working fluids, including gases, liquids and mixtures. This allows you to choose the optimal fluid (characterization and ecological typicality) based on the specific environmental conditions and energy needs of the system.
– Reduction of mass losses: In closed cycles, mass losses of the working fluid are reduced to a minimum, which is particularly advantageous for systems operating in isolated environments or where fluid replenishment is difficult or expensive.
– System durability and reliability: Closed system design tends to better protect the internal components (organisms) of the system from external contaminants, prolonging the useful life of the system and increasing operational reliability.
As can be seen from the application of the principles of thermodynamics to ecological systems, which important authors, such as Y. Prigogine, have defined as nature’s expedient to best dissipate solar energy (which is by far the most available energy on our planet ).
Going from thermodynamics, to ecology and to agricultural and market systems, the step is shorter than you think.
For this reason, so-called zero kilometer products, also known as local or short supply chain products, can significantly contribute to the reduction of greenhouse gas emissions.
In fact, zero kilometer products are usually grown, produced and sold within a radius of a few kilometers (a practical application of the closed thermodynamic cycle). This leads to a significant reduction in emissions from transport, which can represent a substantial part of the total emissions associated with food. To better understand this data, it is sufficient to have some data relating to transport emissions:
– Trucks emit approximately 62 grams of CO2 per tonne of load per kilometer travelled.
– Aircraft emit up to 500 grams of CO2 per tonne of cargo per kilometer travelled.
By reducing the transport distance, a significant amount of CO2 emissions can be saved.
Furthermore, other emissions are linked to conservation and refrigeration.
Imported products often require storage and refrigeration to maintain freshness during transportation. These processes consume energy and contribute to greenhouse gas emissions.
Add to these factors the emissions linked to packaging.
Local products tend to have less packaging than imported products, which need to be more robustly packaged to withstand long journeys.
If we combine this with the possibility of producing through agroecological systems (which are the most energy efficient production models) we further reduce emissions compared to conventional, industrial agriculture.
Staying with emissions related to transport, we can also give some practical examples.
Let’s imagine an example of a food product, such as an apple, imported from New Zealand to Europe.
In this case we will have a transport distance of approximately 18,000 km (mainly by ship).
The resulting emissions will be approximately 1,100 grams of CO2 per kilogram of apples (considering maritime and land transport).
However, if the apple is produced locally, say 100 km away, the emissions will be around 62 grams of CO2 per kilogram of apples (road transport only).
In this example, the emissions savings per kilogram of apples are approximately 1,038 grams of CO2.
Furthermore, as anticipated in relation to the production system (agroecological/conventional), it should be noted that emissions savings are also linked to the use of external inputs used for production. Remembering the closed thermodynamic cycle, the more the inputs come from outside the company (fertilizers, herbicides, fuels, etc.), the more energy-intensive the process will be and, therefore, with increasing emissions. Suffice it to say that nitrogen fertilizations are among the most polluting systems, both for the production method (so-called Haber-Bosch Process) and for the production of further climate-altering gases linked to the formation of nitrogen oxides (NOx) in the soil which due to the negative consequences on the microorganisms of the soil system which, in these conditions, undergo a progressive incapacitation, with highly negative consequences on another process which is the storage of C in the organic substance.
As mentioned, physics (of which thermodynamics is an important branch) is not an opinion but it seems that this is almost totally unknown in market rules and economic and political dynamics.
The consequences are there for all to see and this is why we need to change our way of thinking but, above all, of acting.
Guido Bissanti.
* In a closed thermodynamic cycle, in summary, the system can exchange energies but not masses. Obviously a perfectly closed thermodynamic cycle is almost impossible. The only system that can be considered such, based on the knowledge we have today, is the entire universe.