Food insecurity can be directly exacerbated by climate change due to crop production-related impacts of warmer and drier conditions expected in important agricultural regions 1, 2, 3. However, efforts to mitigate climate change through comprehensive, economy-wide greenhouse gas emission reductions may also negatively affect food security, due to indirect impacts on prices and supplies of key agricultural commodities 4, 5, 6. Here we conduct a multiple model assessment on the combined effects of climate change and climate mitigation efforts on agricultural commodity prices, dietary energy availability, and the population at risk of hunger. A robust finding is that by 2050, stringent climate mitigation policy, if implemented evenly across all sectors and regions, would have a greater negative impact on global hunger and food consumption than the direct impacts of climate change. The negative impacts would be most prevalent in vulnerable low-income regions such as Sub-Saharan Africa and South Asia, where food security problems are already acute.

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For isolated single cells on a substrate, the intracellular stiffness, which is often measured as the Young's modulus, E, by atomic force microscopy (AFM), depends on the substrate rigidity. However, little is known about how the E of cells is influenced by the surrounding cells in a cell population system in which cells physically and tightly contact adjacent cells. In this study, we investigated the spatial heterogeneities of E in a jammed epithelial monolayer in which cell migration was highly inhibited, allowing us to precisely measure the spatial distribution of E in large-scale regions by AFM. The AFM measurements showed that E can be characterized using two spatial correlation lengths: the shorter correlation length, l S , is within the single cell size, whereas the longer correlation length, l L , is longer than the distance between adjacent cells and corresponds to the intercellular correlation of E. We found that l L decreased significantly when the actin filaments were disrupted or calcium ions were chelated using chemical treatments, and the decreased l L recovered to the value in the control condition after the treatments were washed out. Moreover, we found that l L decreased significantly when E-cadherin was knocked down. These results indicate that the observed long-range correlation of E is not fixed within the jammed state but inherently arises from the formation of a large-scale actin filament structure via E-cadherin-dependent cell-cell junctions.

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