by
Sustainability and Circular Economy Lab
University of Gastronomic Sciences of Pollenzo

Photo di Chris Ensminger su Unsplash

What we put on the table determines changes on the thermometer of the planet. Our plate influences the climate and is in turn influenced by it, in a relationship of interconnected dualism. Let us try to understand this mutual influence by analysing some overlapping fronts.

Emissions, from field to plate

Before food reaches our tables, it has to be grown, harvested, raised, transported, processed, packaged, distributed and cooked. Food waste, even if properly disposed of, also contributes to climate-changing emissions. Another not insignificant element is the energy required for all these processes, which must be produced and made available. The agri-food chain consumes 30% of the energy available globally with over 70% consumed beyond the boundaries of the farm (Gao et al., 2017).

In doing so, food production and especially food production solely based on fossil fuels, contributes to increasing the impact of human activities on the Planet. Agriculture is one of the victims of climate change, but at the same time it is one of its architects, contributing ⅓ of the total, to the generation of climate-altering gas emissions released into the atmosphere. These emissions are primarily due to production dynamics. This is what emerges from the recent report "Edgar Food. A global emission database of food systems" (European Commission, 2021), which shows that intensive land use and the general loss of soil vitality account for around 32% of CO2 emissions, agricultural methods for 40% (Crippa et al., 2021), transport for around 5% and packaging for around 9%, and wasted food for around 9%.

 Representation of the main stages in which the food system contributes to the generation of greenhouse gases.

Image source: EDGAR - Emissions Database for Global At (https://edgar.jrc.ec.europa.eu/edgar_food)

In general, we can unfortunately see that CO2 concentrations associated with food production have increased by 145% compared to pre-industrial levels (before 1750). Obviously, this varies from supply chain to supply chain (see table "Food: greenhouse gas emissions along the production chain") but, although global warming is mainly caused by emissions from energy production, it is clear that agricultural activities, livestock and food supply chains can make an important contribution to reducing climate-changing emissions and controlling deforestation.

From beef to nuts: stages and quantities in which CO2 is generated

Photo credit: Hannas Ritchie

Data source: Poore and Nemecek (2019)

Unfortunately, cultivated land is often conceived as a non-living resource, a substrate to be sprinkled with fertilisers, herbicides, insecticides, etc. to increase the yield of the field, without considering the need to preserve its regenerative capacity and the biodiversity that characterises it. Industrial agriculture thus seems not to be aimed at maintaining the chemical-physical and microbiological fertility of the soil, which in the long run leads to soil sterility.

By mainly adopting this mentality, which today we would define as a "linear economy", the agro-industrial sector has contributed to exceeding four of the nine thresholds that determine planetary limits (climate change, loss of biodiversity, alterations to the nitrogen and phosphorus cycle, changes in land use)^[1], i.e. those values within which humanity must move to maintain a state of equilibrium in the biophysical systems that support its existence (Rockstrom, et al., 2009). Humanity's productive needs must therefore be matched by a sense of limitation in making use of what the ecosystems provide. The priority is to slow down the extractive excesses of the current production model in order to manage a dynamic equilibrium relationship with "the best supplier of raw materials known to mankind" (Lovins et al., 1999), namely Nature. One of the main risks that human society is running, in the short and long term, is to incur a loss of efficiency in the use of resources as a consequence of a lack of understanding of the real needs of all the parties involved in the system (Gibbons, 1992). On the contrary, proper land management could activate a process called “soil carbon sequestration”, which would contribute to the storage of carbon within the soil, instead of releasing it (Le Scienze, 2021).

From resource management to the final consumer, there are other situations that have a significant impact. For example, consuming food in places far away from where it was produced means that means of transport (lorries, ships, planes, trains) are needed, most often with refrigeration technologies (energy consumption) to preserve the product. The longer the supply chain, the more we will see an increase in climate-altering gases in the atmosphere due to the logistics of goods. In this respect, it is estimated that the food consumed by an average American family emits around 8 tonnes of CO2 per year. In this figure, transport counts for 5% (Joseph Poore et al, 2018). This means that if a family bought exclusively local products, they would be able to reduce their emissions by at least the same percentage.

Another aspect to consider when talking about the environmental impact of food is food waste. Since food production involves the use of a large amount of water, soil and energy, it is easy to realise that wasted food has a significant impact on climate change, accounting for 8%-10% of total greenhouse gas emissions (WWF, 2021).

The statistics are quite alarming in this case too. According to estimates by UNEP - United Nations Environment Programme - 17% of global food production could be wasted, considering that in 2019 around 931 million tonnes of food waste were generated, 61% of which came from households, 26% from foodservice and 13% from retail.

In conclusion, the 5th "Climate Change" report (2021) by the IPCC (Intergovernmental Panel on Climate Change), the main international body for assessing climate change, tells us how human influence has now drastically warmed the atmosphere, the ocean and the land.

The following have increased (to name but a few of the considerations in the report):

• concentrations of greenhouse gases;
• the global average surface temperature on land (1.59°C) and in the ocean (0.88°C);
• global average precipitation;
• the retreat of glaciers (which is about 40% compared to the early 1970s);
• global ocean acidification;
• global average sea level (which has risen by about 3.7 mm per year since 2006).

The climatic zones are shifting towards the pole in both hemispheres, resulting in a change in the thermal conditions of the cultivated areas, which means, for example, that the 50° north parallel, which is the historic limit of viticulture, is no longer the case due to global warming, as this increase in temperature is pushing the cultivation of vines further north and further up.

Some speak of a phenomenon typical of planet Earth, which by its nature passes between glacial and interglacial periods, but the truth is that in 2019, atmospheric concentrations of CO2 (carbon dioxide) were the highest in the last 2 million years while concentrations of CH4 (methane) and N2O (nitrous oxide) were the highest in the last 800,000 years and both far exceeded the natural multi-millennial changes between glacial and interglacial periods of the last 800,000 years.

The decomposition of the food system into all stages in which a point generation of climate-changing gases could be calculated.

Image source: EDGAR - Emissions Database for Global At (https://edgar.jrc.ec.europa.eu/edgar_food)

Climate change and its consequences on the dinner table

According to the Copernicus Climate Change Service, the global average temperature has risen by 0.26 degrees Celsius compared to pre-industrial levels, but in Italy the thermometer is already 1.5 degrees higher, with peaks as high as +2 degrees in the Alps. Thus the atmospheric patterns linked to seasonality have changed, i.e. the atmospheric circulation patterns or interconnection networks that help define the behaviour of the climate. In short, when we say 'there are no more mid-seasons' we are not filling our mouths with empty words and platitudes, we are describing the current situation. What does this mean for the food we eat? Let us look at some aspects on a national scale.

Let's take water as an example. The choice of one method of irrigation over another depends on several factors, such as water availability, morphology and lie of the land, climate, location of the water source, etc. The water used in the paddy fields of the Po Valley, for example, comes from the Po and the Dora Baltea and has always been so, since the time of Ludovico il Moro (Duke of Milan from 1480 to 1499). If the temperature rises, especially in summer, or if there is not enough rain between February and March (as has been the case in recent years), the volume of glaciers decreases (IPCC, 2013). Consequently, adding a decrease in rainfall and an increase in heat waves (IPCC, 2013), the flow of our rivers is reduced, putting the work of Italian rice producers at serious risk. The impact of climate change could lead to a progressive diffusion of irrigation systems even in areas where they were not present or necessary before.

Heat and drought are also hastening the ripening of fruit trees. One example is the alarming news from the wine-growing sector, where warmer temperatures are forcing companies to bring forward the harvest. We are talking about 10 days on average, with peaks of two weeks for the producers most affected. This is also having an effect on the final product: a higher concentration of sugars in the grapes means that the wines will be more alcoholic. As the heat increases, so does the proliferation of new pests, brought in from around the world with the globalisation of markets. For example, the Popillia Japonica (a beetle native to Japan), which arrived in Italy in 2014, devastates crops and attacks wild, ornamental and forestry plants, leading to defoliation and destruction of the plant and flowers (Emilia Romagna Region, 2021). In addition to these problems caused by alien species, there is tropicalisation, i.e. the change in climate in temperate areas, which tend to take on characteristics of intertropical climates. This situation favours the formation of pseudo-cyclones, i.e. torrential rainfall that we commonly call 'water bombs'. The violence and unpredictability of these phenomena jeopardises harvests, especially when combined with the sudden frosts of the spring months. When the long nights with the mercury dropping below zero arrive after days of early summer weather, the repetitive alternation of weather can wipe out harvests and the income of many agricultural activities in a matter of minutes. According to Arpa data, between 6 and 7 April 2021 we had a very cold spell, with a temperature drop of 15 °C, snow showers of up to 300-500 metres from the north to the southern Apennines and even flakes as far as the sea in Trieste. Temperatures this low in April had not been seen for 20-30 years or more (lows of -9 °C in the Arezzo area, -6 °C in Perugia, -5 °C in Verona), beating the record of 8 April 2003 in various places. This sudden frost causes serious damage to agricultural crops and orchards, which were awakened early by the exaggerated heat of late March and early April (Nimbus, 2021).

According to the United Nations Intergovernmental Panel on Climate Change (IPCC) - the global scientific body dedicated to the study of climate change - the adoption of more sustainable agronomic practices could reduce emissions responsible for global warming to 5.5-6 billion tonnes by 2030 (Ismea, 2014). Much can be done through carbon sequestration in the soil, the containment of methane in livestock and rice fields and the reduction of N2O (nitrous oxide) emissions in arable crops.

How can we help reduce our impact on the climate?

Discover with us 4 good tips:

• 1. Eat less meat and replace it with more cereals and legumes

  These behaviours could save up to 750 kg of CO2 emissions per person per year (Eating Planet, 2016). The report 'Climate change and Land' (IPCC, 2019) describes plant-based diets as a great opportunity to mitigate and adapt to climate change. The reason for this would be the intensive use of agricultural land for feed production, deforestation to make room for arable land for meat production and/or feed for livestock, manure from farmed animals as a release of methane gas into the atmosphere.

   

  Photo by Laure Noverraz on Unsplash

• 2. Choose, whenever possible, a zero kilometre supply chain

  This simple action can result in significant mitigation of anthropogenic environmental impact (Webb et al., 2013), considering that road, air, rail and sea transport produce 60%, 20% and 10% of the world's carbon emissions in food transport respectively (Paxton, 1994).

  Thanks to the "virtual shopping trolley", a project carried out by the WWF association (2010), you can also understand how much the length of the food chain and the production characteristics affect the production of polluting emissions. For example, looking at a typical 500 gram bag of pulses bought at the supermarket, we find that there are differences in terms of carbon dioxide released into the atmosphere:

  • Legumes 500 g bag, non-local, non-seasonal, non-organic 1.37 kg CO2 eq2 eq
  • Legumes 500 g bag, non-local, non-seasonal, organic 1,08 kg CO2 eq
  • Legumes 500 g bag, local, seasonal, organic 0.7 kg CO2 eq

   

  Photo by Elaine Casap on Unsplash

• 3. Do not waste food

  According to the Food and Agriculture Organisation of the United Nations (FAO), if food waste were a country, it would be the third largest emitter of greenhouse gases in the world after the United States and China. In fact, unfortunately, 30% of the food we produce is wasted, or about 1.8 billion tonnes per year. If, as humanity, we stopped wasting food altogether, we would eliminate about 8% to 9% of our total emissions (FAO, 2011). Acting on food waste and food loss - i.e. food discarded by suppliers or consumers and food 'lost' during the early stages of production (harvesting, storage and transport) - would clearly mitigate climate change.

   

  

  Photo by Elevate on Unsplash

• 4. Buy food produced according to seasonality

  One of the advantages of consuming food seasonally is clearly the reduction of greenhouse gases because, for example, it does not require the energy input for heating or artificial lighting needed to produce crops outside the natural growing season (Macdiarmid, 2014). However, it should be considered that seasonality and its environmental consequences depend on the product we are analysing and are not equally effective in mitigating emissions (when compared to the amount of CO2 emissions generated) when compared to the potential reduction of food waste and cutting meat consumption (Coley, Howard & Winter, 2009).

   

  Photo by Phuc Long on Unsplash

Download for more informations:

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