It was in the beginning of this century when I still believed that shifting our economies´ material supply to renewables and use more biomass towards this end would make sense. It took me some years to get a grant for studying the potentials for producing non-food biomass for material purposes in Germany, but when it started the hype of first generation biofuels had started and dominated non-food biomass.

Our scenario calculations, performed 2007-09, showed that the cropland footprint of Germany would drastically grow beyond our territory. Subsequent studies for the European Union exhibited the same, in particular as consequence of growing use of biomass for energy purposes. Heavy transformation of grasslands, savannahs and forests, in particular in the tropics, had to be assumed as a consequence.

We suggested a proxy threshold of sustainable global land use: 0.20 ha/person cropland in 2030 related to the consumption of agricultural goods (Bringezu et al. 2012). The rationale was simple, as the expansion of cropland was known to be a major driver of losses of biodiversity worldwide, so that one precondition for halting that loss would be to halt the expansion of cropland. That value was accepted in a UNEP (2014) report, and still contributes to discussions on science based targets (Bringezu 2019).

In 2017 we got the unique chance to study the footprints of the German bioeconomy more extensively (Bringezu et al. 2020, 2021). Indeed, the past trends of contributing drastically to land transformation due to our overall consumption were corroborated, while ongoing trends would lead to lower pressure of induced land conversion in the future. However, in 2030, German consumption would still require more than 0.20 ha/person cropland, if no additional measures for increased resource efficiency and societal sufficiency would be taken.

Moreover, other issues may grow in relevance such as supply from regions with high water stress, and the prospectively growing forestry biomass footprint of Germany for supplying growing exports.

Today, I think we should be very careful when addressing biomass as a "renewable resource". In fact the global demand for biomass-based products has led and will further lead to an overexploitation of natural ecosystems and a degradation of natural functions for people. Our economies will need to increase the efficiency of using biomass (and mineral) resources significantly, and we need to adjust our countries´ final consumption of products to levels which can be supplied sustainably. Monitoring the resource and climate footprints of countries and products may help to provide orientation.

Bringezu, S., Distelkamp, M., Lutz, C., Wimmer, F., Schaldach, R., Hennenberg, K., Böttcher, H., Egenolf, V. (2021): Environmental and Socioeconomic Footprints  of the German Bioeconomy. Nature Sustainability, https://doi.org/10.1038/s41893-021-00725-3

Bringezu, S., Banse, M., Ahmann, L., Bezama, A., Billig, E., Bischof, R., et al. (2020): Pilotbericht zum Monitoring der deutschen Bioökonomie. Hrsg. vom Center for Environmental Systems Research (CESR). Universität Kassel. Kassel, doi:10.17170/kobra-202005131255

Bringezu, Stefan (2019): Toward Science-Based and Knowledge-Based Targets for Global Sustainable Resource Use. Resources 2019, 8, 140; DOI: 10.3390/resources8030140

Bringezu, S. O’Brien, M., Schütz, H. (2012): Beyond biofuels: Assessing global land use for domestic consumption of biomass – A conceptual and empirical contribution to sustainable management of global resources, in: Land Use Policy 29, 224-232

UNEP (2014): Assessing Global Land Use: Balancing Consumption with Sustainable Supply. Bringezu, S., Schütz, H., Pengue, W., Brien, Ó., Garcia, F., Sims, R., Howarth, R., Kauppi, L., Swilling, M., Herrick, J., A Report of the Working Group on Land and Soils of the International Resource Panel, http://www.resourcepanel.org/reports/assessing-global-land-use