We need land to produce food. But today around 9% of humanity is starving and at the Amazon woods are on fire (#1, #2). So, to feed all people, we need more arable land.
In the future we also want to avoid fossil resources. We can then use biofuels for aircrafts and ships (#3). Plastics should be bio-plastics (#4).
Agriculture shall become more sustainable, but organic farming needs 15% more land area (#5). Also, more space should be given to biodiversity.
According to the IPCC, we even have to remove carbon dioxide from the atmosphere to save the climate (#6). Here, afforestation can make a significant contribution (#7).
For all this we need more fertile land. But that does not exist.
Yet agriculture has actually doubled its productivity in the last 40 years (#2). Unfortunately, the rapid growth of world population has – literally – eaten up much of this agricultural progress (#1).
Despite these increasing demands, agriculture can do all this for us. However, one prerequisite is that we stop eating animal-based food (#8, #9). This is because today we produce animals on 80% of our agricultural land, but they provide only 18% of our calories (#2). Animal production is thus extremely inefficient. Only if we avoid this inefficient production, we will have a chance to sustainably produce all we need for a good life for all people on this earth on the available land area (#10).
#1 UN DESA, World Population Prospects, https://population.un.org/wpp/
#2 UN FAO, FAOSTAT, http://www.fao.org/faostat/en/#data/
#3 Ships and airplanes can only be powered by liquid fuels at the current state of technological development. As an alternative to bio-based fuels, such fuels are conceivable which are obtained from carbon dioxide, which must be separated from the atmosphere in the large quantities required in a decarbonised world. This in turn requires considerable additional amounts of renewable electricity, which, even according to optimistic estimates, will require at least twice as much renewable electricity as was generated at the time when the carbon dioxide was produced by combustion in coal-fired power plants (from a company that would like to sell such technology: D.W. Keith, G. Holmes, D. St. Angelo, K. Heidel, 2018: A Process for Capturing CO2 from the Atmosphere. Joules 2, 1573-1594, https://doi.org/10.1016/j.joule.2018.05.006). This is a significant resource requirement that does not occur with bio-based fuels.
#4 Even with an increased recycling rate, there will still be a significant demand for fresh plastics in the foreseeable future. Alternatively, carbon dioxide can be used again, with the corresponding consequences (#3).
#5 E. Malézieux, C. Lesur-Dumoulin, T. Ben-Ari, C. Langlais, D. Makowski, 2018: Yield variability in organic versus conventional systems: a meta-analysis for horticultural systems. PS-8.1-02. In: Book of abstracts of the XV European Society for Agronomy Congress: “Innovative cropping and farming systems for high quality food production systems”. Agroscope. Genève: Agroscope, Résumé, p. 52. European Society for Agronomy Congress (ESA 2018). 15, Genève, Suisse, 27 August 2018/31 August 2018. https://agritrop.cirad.fr/588921/
K. Mondelaers, J. Aertsens, G. Van Huylenbroeck, 2009: A meta-analysis of the differences in environmental impacts between organic and conventional farming”, British Food Journal 111(10) 1098-1119. http://dx.doi.org/10.1108/00070700910992925
#6 IPCC, 2018: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. In Press, https://www.ipcc.ch/sr15/.
#7 Afforestation is the cheapest option for so-called negative emissions, which can already be implemented on the required scale today and is also accepted by society (J.C. Minx et al., 2018: Negative emissions – Part 1: Research landscape and synthesis. Environ. Res. Lett. 13, 063001. https://doi.org/10.1088/1748-9326/aabf9b).
#8 A. Pfennig, 2019: Sustainable Bio‐ or CO2 economy: Chances, Risks, and Systems Perspective. ChemBioEng Reviews 6(3), 90-104. http://dx.doi.org/10.1002/cben.201900006.
A. Pfennig, 2019: Klima-Wende-Zeit: Warum wir auch bei Ernährung und Entwicklungshilfe umdenken müssen. Books on Demand, Norderstedt, http://hdl.handle.net/2268/242314.
#9 A further prerequisite is that the growth of the world population will decline in the future, which finally presupposes economic development of currently less developed countries. However, in the land area balances (#8), for example, it was optimistically assumed that agricultural productivity, both for crops and animal production, will continue to increase as in the past, although, for example, a decrease in productivity can already be observed in Europe today, e.g. for wheat, as a result of climate change (#2).
#10 Even if the above-mentioned demands, which can be met with carbon dioxide from the atmosphere (#3, #4), are realised in this way and the demand for land area decreases accordingly, and even if the optimistic assumptions in the land area balances (#9) materialise, the consumption of animal-based food must be significantly reduced. If the world population grows according to unfavourable scenarios, land area will not suffice to achieve all sustainability goals despite the optimistic assumptions. And even if the future develops according to all optimistic assumptions, there would be no harm if humanity kept a larger distance from the planetary boundaries. Especially the consequences of the COVOD-19 pandemic teach that a certain so-called resilience, i.e. the ability to react appropriately to unexpected negative events, is by no means harmful. With less consumption of animal-based food, the increasing food shortages that are currently anticipated could be countered more easily.