Global land footprint associated with FLW
In 2018, approximately 800.3 Mha of agricultural land (i.e., land footprint) was used to produce 2,247.6 Mt of food (accounting for 22.6% of global primary production) that ultimately ended up as FLW. This substantial FLW and land footprint were predominately generated in several countries with large populations or high consumption levels (Fig. 1a,b).
From 2000 to 2018, global FLW and land footprint increased by 483.8 Mt (+ 27% compared to 2000) and 237.8 Mha (+ 42% compared to 2000) respectively, creating rapidly increasing environmental impacts4,28, including biodiversity hotspots33. FLW growth occurred primarily in fast-growing economies (Fig. 1c), especially Brazil (increased by 74.1 Mt, same below), China (46.7 Mt), and Iran (30.5 Mt) among BRICS countries. The situation was similar for land footprints (Fig. 1d). However, in Africa, where the growths of FLW volumes were not so severe, the increases in FLW ratios were definitely shocking (Supplementary Fig. 2). Unlike other countries where ratios of food loss and food waste generally fluctuated, most African countries have experienced increases in both ratios over the past two decades, with some countries increased by more than 5% in both. This implies that if food production in Africa had stagnated over these years, the nutritional supply would have been significantly reduced, exacerbating instability risks and increasing environmental pressure in poverty areas.
If using gross domestic product (GDP) growth rates between 2000 and 2018 as proxies for countries’ development speeds, then higher FLW increases primarily came from countries with higher GDP growth rates. (Fig. 1e). Furthermore, the top 10 countries accounted for 54.1% of the global FLW (Fig. 1f) because of their large populations and food consumption patterns. Notably, China, the United States, India, and Brazil were the main contributors, consistent with previous study4, collectively generating 39.2% of the global FLW. While the increase in land footprint was predominately in countries with higher GDP growth rates (Fig. 1g), countries with higher FLW volumes did not necessarily generate higher land footprints (Fig. 1h) because land footprints were closely related to food categories and production intensity. For instance, China produced the highest FLW but not the highest land footprint due to its focus on horticulture (vegetables, fruits, and nuts), which is intensive in capital and labor but less demanding in land use. The United States had the highest land footprint, accounting for 10% of the global land footprint. Australia and several African countries generated large land footprints but did not rank in the top 10 for FLW.
FLW and land footprint varied by region and dietary pattern. Horticulture dominated FLW in EU, Asia, and Africa (Fig. 1i), contributing 40.5% to the global FLW (Fig. 1j); however, it only contributed 10.2% of the global land footprint owing to its intensive operation characteristics (Fig. 1k,l). In contrast, FLW from meat and animal products resulted in substantial land footprints in most regions (60.0% of the global land footprint) because pasture was characterized by extensive operation. In addition, FLW from meat and animal products was more prevalent in regions with higher meat consumption preferences, such as Northern America and Oceania (NAM + OC)4, where 31.9% of FLW came from meat and animal products (Fig. 1i). The share of oil and sugar crop FLW in Latin America and the Caribbean (LAM + CAR) was approximately 52.3%, which was much higher than the global average of 25.1%. More detailed information on the 10 food contributions is provided in Supplementary Fig. 3. Overall, a few countries dominated the growth of FLW and global land footprint, which may further exacerbate related environmental issues in the future.
Land footprint flows embedded in global food trade
In 2018, approximately 15.9% of the global land footprint was associated with food trade. Virtual land flows embedded in the food trade mainly flowed from LAM + CAR and NAM + OC to Eastern Asia and South-eastern Asia (EA + SEA), Western Asia and Northern Africa (WA + NAF), and EU (Fig. 2a,b).
Countries with the highest export-embedded land footprint included the United States, Russia, Argentina, and Zimbabwe, which together covered 26.5% of the global land footprint exports (Fig. 2c). The most import-embedded land footprint countries included China, the United States, Russia, and Japan, accounting for 25.6% of the global land footprint imports.
From 2000–2018, the trade-embedded land footprint grew from 106.1 Mha to 166.5 Mha (Supplementary Fig. 4). Especially for China, which was the highest net importer of land footprints in 2018, the virtual land flows from the United States and Brazil to China together accounted for 4% of global total imports and increased by 2 and 10 times in last two decades, respectively. Its increasing FLW imports may motivate agricultural production and enhance environmental impacts for exporters. In contrast, Japan and some EU countries showed a decrease in their land footprint imports (Supplementary Fig. 4f), which may be dependent on improved food supply technologies and the implementation of anti-food waste laws33.
Potential biodiversity loss
FLW exacerbates the challenge of meeting rising food demands by necessitating additional land transformation for compensatory production10,11 to bridge the gap between food supply and demand. Land transformation often involves converting natural habitats into agricultural land through rapid cropland expansion15,35. Given the long recovery period needed to restore biodiversity36 and ecosystem quality37 on converted land, we evaluated the associated biodiversity loss by aggregating the impact over the entire regeneration period (in species*year)38 as in previous studies35,39. Potential biodiversity loss was assessed at the regional and global scales, where regional biodiversity loss is defined as the regional extinction of non-endemic species that can be recovered by migration from other regions, and global species extinction represents an irreversible global extinction of endemic species.
Globally, the FLW-related land footprint in 2018 was estimated to have resulted in a regional species loss of 543,371 species*year (Fig. 3a) and a global species extinction of 13,920 species*year (Fig. 3b), with the greatest biodiversity loss occurring in LAM + CAR and EA + SEA.
Around two-thirds (66.3%) of the regional species loss occurred in birds, whereas amphibians, reptiles, and mammals accounted for 5.2, 12.1, and 16.3%, respectively. Comparatively, the four taxa were more evenly affected in terms of global species extinction, with birds, amphibians, reptiles, and mammals accounting for 27.4, 36.1, 20.1, and 16.4%, respectively.
Biodiversity losses were concentrated in countries with higher land footprint generation or exports. From the average perspective of these two types of biodiversity loss (Fig. 3c,d), the greatest biodiversity loss occurred in China (8.1% globally) due to its large land footprint generation, which put great pressure on domestic production, even when compensated by the highest land footprint imports. Owing to the larger land footprint bases, Mexico, India, and Indonesia accounted for 6.7, 5.8, and 4.7% of global biodiversity loss, respectively. The remaining biodiversity losses were concentrated in major exporters of land footprint, such as Brazil, the United States, and Australia. However, due to the lower species richness in high-latitude areas, biodiversity in Russia and Canada was less affected, even when their land footprint exports were relatively high.
Resources conservation in FLW reduction scenarios
While eliminating FLW may be unrealistic, targeted FLW reduction efforts can lead to significant impacts on land resources and biodiversity. To this end, four FLW intervention strategies were established (Methods), with the cascade mechanisms depicted in Supplementary Fig. 5. Generally, reducing FLW depresses domestic food production and imports but enhances exports, triggering a cascading effect that contracts global food production through the food trade, thereby stimulating land abandonment and curbing cropland expansion to conserve biodiversity.
Approximately 355.0 Mha of land footprint (44.4% globally) could not be generated if all countries could halve FLW, which roughly meets the SDG Target 12.3 (Sall; Fig. 4a).
The reduction in land footprint associated with food waste is concentrated in NAM + OC and EU, highlighting the importance of reducing food waste on the table in related countries. Comparatively, halving FLW in only the top 10 countries with the highest FLW could reduce the global land footprint by 175.4 Mha (21.9%; Stop10; Fig. 4b). The saved food can be used to more adequately meet domestic consumption and export demands, prompting other countries to boost their imports and reduce their domestic production. For instance, this would reduce Argentina’s land footprint by 35% without any domestic FLW reduction measures. The reduction of land footprint in Stop10 is primarily in areas with higher species richness or biomass, leading to a reduction in biodiversity loss of 33.2–34.7% (Fig. 4e), which is more than half of the conservation benefits in Sall.
Meat and animal products accounted for a relatively low share of global FLW. Thus, halving meat and animal product FLW (Smeat; Fig. 4c) could only require a 7.0% reduction in global FLW but result in a 30.7% land footprint reduction, making it quite cost-effective in terms of land conservation. Furthermore, the land-saving benefit of halving FLW in 40 biodiversity hotspot countries (Shotspot; Fig. 4d) was between Stop10 and Smeat but its biodiversity conservation benefit was much closer to Stop10. This means that even when only the top 10 countries or biodiversity hotspots halve FLW, the conservation effect on biodiversity will be greater than the total efforts of the remaining countries to halve FLW.
Due to the extremely high FLW volume, China was the country with the highest biodiversity conservation benefits in all scenarios, accounting for an average of 23.8% of regional species loss (Supplementary Fig. 6) and 19.0% of global species extinction (Supplementary Fig. 7). In addition, India, Japan, and the Philippines also experienced significant reductions in biodiversity losses from scenarios other than Smeat, resulting in higher biodiversity conservation benefits in EA + SEA (Supplementary Fig. 8). Meanwhile, the sharp decline in food exports would greatly alleviate potential species extinction in LAM + CAR, which could ease pressure on biodiversity hotspots in South America that are experiencing threats from cropland expansion.