Global market integration increases likelihood that a future African Green Revolution could increase crop land use and CO2 emissions
Global market integration increases likelihood that a future African Green Revolution could increase crop land use and CO2 emissions
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DOI：
10.1073/pnas.1403543111
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发表时间：
2014-09-23
影响因子：
11.1
通讯作者：
Baldos, Uris Lantz C.
中科院分区：
文献类型：
--
作者：
Hertel, Thomas W.;Ramankutty, Navin;Baldos, Uris Lantz C.
人们对农业生产力对土地使用和环境的影响重新产生了兴趣。这场争论的核心是农业创新就是节约土地。然而，许多个案研究和全球经验研究发现，几乎没有证据表明，产量增加会伴随着面积减少。我们发现，这些研究忽略了两个关键因素：对真实反事实情景的估计，以及倾向于采用区域而不是全球视角。本文介绍了一个分析区域和全球创新对长期作物产量、价格、地租、土地利用和相关二氧化碳排放影响的总体框架。这样做有助于调和农业生产力增长对全球土地使用和环境质量的影响方面显然相互矛盾的观点。我们的历史分析表明，亚洲、拉丁美洲和中东的绿色革命无疑是节约土地和排放的，而与之相反的世界却没有这些创新。相比之下，我们发现，未来的非洲绿色革命的环境影响是潜在的模糊。我们将这些不同的结果追溯到创新地区与世界其他地区在产量、排放效率、耕地供应反应和集约化潜力方面的相对差异。农业全球化增加了对环境产生不利后果的可能性。然而，如果持续几十年，非洲的绿色革命最终将成为土地节约。
There has been a resurgence of interest in the impacts of agricultural productivity on land use and the environment. At the center of this debate is the assertion that agricultural innovation is land sparing. However, numerous case studies and global empirical studies have found little evidence of higher yields being accompanied by reduced area. We find that these studies overlook two crucial factors: estimation of a true counterfactual scenario and a tendency to adopt a regional, rather than a global, perspective. This paper introduces a general framework for analyzing the impacts of regional and global innovation on long run crop output, prices, land rents, land use, and associated CO2 emissions. In so doing, it facilitates a reconciliation of the apparently conflicting views of the impacts of agricultural productivity growth on global land use and environmental quality. Our historical analysis demonstrates that the Green Revolution in Asia, Latin America, and the Middle East was unambiguously land and emissions sparing, compared with a counterfactual world without these innovations. In contrast, we find that the environmental impacts of a prospective African Green Revolution are potentially ambiguous. We trace these divergent outcomes to relative differences between the innovating region and the rest of the world in yields, emissions efficiencies, cropland supply response, and intensification potential. Globalization of agriculture raises the potential for adverse environmental consequences. However, if sustained for several decades, an African Green Revolution will eventually become land sparing.