Misplaced optimism in agricultural land usage driven by newly available climate resources: A case study of estimated and realized cropping intensity in northern and northeastern China

摘要

Global climate change may provide new opportunities for agricultural development at higher latitudes. High expectations for increasing cropping intensity have driven increases in crop production in northeastern and northern China. However, effectively utilizing the increased climate resources available at higher latitudes (due to longer growing seasons) remains controversial due to the increased risks involved. Here, we employed a phenology-based sliding segmentation algorithm and cropping system zoning index to survey the development of actual and potential multiple-cropping systems. Our results revealed that the development of multiple cropping clearly lags behind its increased potential area, as the actual multiple-cropping area increased by only 7.06% over the past 30?years. The use of newly available climate resources is quite low (≥0.86%), especially given the newly available potential multiple-cropping area. Consideration of results from Chile, Brazil, Vietnam, and the Nordic countries shows that cropping intensity development due to climatic warming face limitations from climate risk that must be reasonably addressed to achieve the potential benefits. Other barriers to the full use of such new environmental resources include proper information, conservative farmer behavior, agricultural product prices, and labor transfers. Therefore, any hypothesized optimism that the simple addition of climate resources would result in the effective utilization of arable lands is misplaced, and more cautious estimates of the potentially positive effects of climatic change on agricultural production should be emphasized by both scientists and policy makers.