Climate, food & national security

It's widely accepted that climate change can impact on food availability in developing countries, potentially leading to conflict.  But what about developed nations such as the UK or the USA?  Could our own food supplies be threatened by climate change?  Could the complexity of our supply chains make us more vulnerable than we realise?  
ffinlo Costain speaks to Caitlin Werrell, the co-founder of the Washington-based Centre for Climate & Security, which works closely with the Pentagon, and to Rear Admiral Neil Morisetti, the UK's former Climate, Energy & Security Envoy.
Produced by Farmwel.