When it comes to global warming and the production of greenhouse gases, an immediate association is made with the use of fossil fuels. But the human activities that cause these emissions are not limited to energy consumption. Those associated with soil and forest management, agriculture and livestock farming also make a significant contribution. In technical terms, the sector that includes these particular types of human activities is known as AFoLU (Agriculture, Forestry and other Land Use).
How polluting are human activities?
The IPCC (Intergovernmental Panel on Climate Change, the leading international body for assessing climate change) estimates that the AFoLU sector is currently responsible for annual greenhouse gas emissions of 12 billion tons of carbon dioxide equivalent (the unit of measurement of greenhouse gases), or about 23 percent of total emissions of human origin. A high percentage, which deserves attention and requires preventive measures. The figure for emissions from the AFoLU sector does not include those deriving from energy consumption (which are included in the total greenhouse gas emissions from the energy sector). The sources of emissions from this particular sector are different, originating from human interventions that trigger multiple and often complex interactions with soil, biomass and the atmosphere, which in turn cause the formation and release of greenhouse gases into the atmosphere. As the science that governs these phenomena is complex and emissions are widespread, it is difficult to measure and control them accurately, although - as we have seen - they are significant and need to be reduced in order to limit the increase in the temperature of the Earth by the turn of the century.
The main causes
For a clearer picture of the type of activity we are referring to, let's examine some of the most significant. The first is man-made deforestation, caused by the demand for new land for cultivation or pastures, both to meet the growing food requirements of an ever-expanding population and for the production of biofuels (a more recent phenomenon). The soil and the natural forests that grow on it are in fact huge reservoirs of carbon contained in the organic substance of which they are largely composed. Thanks to the process of photosynthesis, which captures atmospheric CO2 and transforms it into the organic matter of which the leaves, branches, stems and roots are made, forests, in particular, have accumulated carbon over the centuries. If all the carbon in the soil and forests were transformed back into carbon dioxide, between 2,000 and 3,000 billion tons of CO2 would be emitted into the atmosphere (IPCC estimate), an enormous potential considering that in a year the total emissions of human origin are just over 40 billion. Unfortunately, for some time now, various kinds of human behavior has begun to provoke this process. These include the burning of millions of hectares of natural forest precisely to clear new land for agriculture and which, due to the combustion of biomass, transforms the previously accumulated carbon back into carbon dioxide, releasing it into the atmosphere. A second source of emissions is the intensive breeding of cattle and pigs. In fact, livestock release large quantities of greenhouse gases (carbon dioxide, methane and nitrous oxide) mainly from the digestion process and from the decomposition of manure. How can these emissions be combated and reduced? There are multiple solutions to this question, encompassed in studies and interventions that come under the umbrella of “sustainable agriculture” or “Natural Climate Solutions” (NCS).
The good practices that would make agriculture sustainable include the greater use of “marginal” land (which is difficult to cultivate, unproductive and in the process of being abandoned), the recovery of land undergoing desertification and agricultural practices which lead to an increase in productivity. Other interventions can help ease the pressure on agriculture and livestock on the demand side, promoting the elimination of food waste and the adoption of a proper balanced diet which, in developed countries, prevents the excessive consumption of food (with the added benefit of reducing the harmful phenomenon of obesity). “Natural Climate Solutions” (NCS) include conservation, restoration and land management activities that increase or maintain stable the amount of carbon stored in natural forests, wetlands, grasslands and agricultural land, avoiding CO2 emissions. These include initiatives to prevent deforestation, such as the REDD+ (reducing emissions from deforestation and forest degradation) program. Set up within the framework of the United Nations, this program provides for different types of interventions, to be implemented in developing countries, both to protect and restore forest areas and to implement other mitigation plans related to restoring ecosystems. These projects - if conducted according to precise rules - can generate “negative emissions” certificates for the benefit of those who implement or finance them. Eni is also carrying out important initiatives in these fields, including the production of “advanced biofuels” from biomass that is either waste or does not compete with agricultural production, which we already mentioned in a previous article. Another one involves the implementation of major REDD+ type projects. This deforestation prevention activity not only achieves climate and environmental benefits, but also promotes the social and economic development of the local populations that host it and contributes to the achievement of the UN’s Sustainable Development Goals (SDGs).
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