Traders in Food Systems are Keystone Actors for Water Stewardship

Unaltered biosphere is the main mankind ally in mitigating climate changes. Biosphere stewardship indicates traders, identified as Transnational Corporations (TNCs), as a keystone actor of the global Production Ecosystem and a major driver of the outsized impact on the biosphere. Yet, despite water is the blood of the biosphere, efforts to analyse the role of TNCs in reallocating global water resources have been poor. Capitalizing on the high-resolution data by the Trase initiative and by focusing on the paradigmatic case of the Brazilian soy, we found that major soy traders displace on average twice as much virtual water as top-importing countries- except for China. Bunge virtual water export in 2018 reached 15 Gm³, almost twice the export of Thailand (7.8 Gm³) and that of Louis Dreyfus more than twice the one of Netherlands (4.6 Gm³). Results also show that companies face local water risk through the exposure to drought (30-45% probability of occurrence), which can disrupt along the whole supply-chain. Countries, which have been considered as far the main player to achieve sustainable supply chains, are strongly tied to companies and thus are not able to properly act without joint efforts with traders. In strong analogy with the ocean stewardship we argue that TNCs should be recognized as Keystone Actors for water resources conservation and should cooperate with science, local authorities and communities to assure the integrity of water reserves and the hydrological cycle, global commons of the biosphere.未受干扰的生物圈（biosphere）是人类减缓气候变化的核心盟友。生物圈管护将被界定为跨国企业（Transnational Corporations, TNCs）的贸易商，视为全球生产生态系统（Production Ecosystem）的关键核心主体，亦是对生物圈造成过度影响的主要驱动因素。然而，尽管水是生物圈的命脉，针对跨国企业在全球水资源再分配中所扮演角色的研究仍较为匮乏。本研究依托Trase倡议（Trase initiative）发布的高分辨率数据，并以巴西大豆为典型研究案例，结果发现：除中国外，主要大豆贸易商的虚拟水（virtual water）输出量平均是顶级进口国的两倍。2018年，邦吉（Bunge）的虚拟水出口量达15吉立方米，几乎是泰国（7.8吉立方米）的两倍；路易达孚（Louis Dreyfus）的虚拟水出口量则是荷兰（4.6吉立方米）的两倍有余。研究结果还显示，这些贸易商面临着由干旱引发的本地水资源风险——干旱发生概率达30%-45%，该风险可能会波及整条供应链（supply chain）。长期以来被视作推动可持续供应链建设核心力量的国家，与贸易商绑定紧密，因此若不与贸易商携手合作，这些国家便无法采取有效应对行动。类比海洋管护的实践逻辑，我们主张应将跨国企业认定为水资源保护的关键核心主体，并推动其与科研机构、地方政府及社区开展合作，以保障水资源储备与水文循环（hydrological cycle）的完整性——这二者均属于生物圈的全球公共资源。