Scale matters, but not always by scaling up

Humans have spread out of Africa into all continents, except Antarctica. Food availability and adaptability to diverse food were drivers for this expansion impacted by geological and climate processes. Humans themselves also shaped landscapes and biodiversity by eradicating many bigger species (Frankopan 2023). The industrial revolution with massive deployment of fossil energy replacing muscle power of humans and domesticated animals increased CO2 and methane emissions. The ‘great acceleration’ after WWII led to the well-known ‘hockey stick’ effect (Steffen et al. 2015). The massive upscaling through industrialisation transformed food production, distribution and consumption. The trend towards standardisation and spatial expansion of industrial agriculture generated increasingly highly processed food. Energy demand per unit output increased on land with reliance on artificial fertilizers, factory farming and intensive pest and disease control. Its pollution of surface, ground and coastal waters, industrial agriculture has contributed to breaching planetary boundaries.A similar pattern has arisen in marine food production. While the ocean is one huge interconnected ecosystem, local and regional temperature, salinity and habitats create distinct floral and faunal niches. The scaling up of industrial fishing has, similar to earlier trends on land, significantly changed the faunal size distribution. Top predators that maintain marine food webs have declined, e.g. in the North Atlantic to less than 10% of their biomass a century ago (Christensen et al. 2003). Excessive, unselective extractions create waste and shrink global landings serving as nutritious food. Conversely, improved utilisation and management can increase nutritional effects. Here it is argued that phasing out unselective and particularly destructive forms of fishing and replacing them with local, low impact fisheries would climate proof marine harvesting and enhance justice by benefit sharing (Nauen et al. 2025). The appropriate harvesting scale uses basic principles: let juvenile fish grow to maturity; avoid fishing large, old females with the highest reproductive capacity; fish prey less than predators; harvest only what can regrow, shored up by strongly enforced protected areas. Such technical measures should be underpinned by inclusive management practices that are gender aware and value ecological knowledge of small-scale fishers and science. In many coastal areas scaling down or sideways towards local, low-impact, small-scale fisheries offers more cost-effective and environmentally benign, high quality nutrition and other social benefits. Increased ocean literacy combined with attention to social justice are major enabling factors for steering transitions towards viable regenerative food production systems.ReferencesChristensen, V. et al. (2003). Hundred-year decline of North Atlantic predatory fishes. Fish Fisheries, 4(1), 1-24 https://doi.org/10.1046/j.1467-2979.2003.00103.xFrancopan, P. (2023). The Earth Transformed. An Untold History. London, Oxford, New York, New Delhi, Sydney, Bloomsbury Publishing, 696 p. ISBN 978-1-5266-2255-5Nauen, C.E. et al. (2025). Voices from the shorelines to navigate the anthropocene. Ch. 9 in M. Bohle and C.E. Nauen (eds.). Cross-Disciplinary Dialogues with the Earth Sciences, https://doi.org/10.1007/978-3-031-97445-8_9Steffen, W. et al. (2015). The trajectory of the Anthropocene. The great acceleration. The Anthropocene Review, 2, 81-98. https://doi.org/10.1177/2053019614564785