BusinessGreen: Investors are facing fresh calls to build up the resilience of their agricultural portfolios, after a major new report showed $8trn (5.2trn) worth of farming assets could become uninsurable owing to environmental risks linked to climate change. The report, released today by the University of Oxford's Smith School of Enterprise and the Environment, aims to show the scale of the asset bubble faced by the agricultural sector, which could leave huge levels of capital exposed to the physical and economic...