The coronavirus pandemic is putting untold pressure on the supply chains that produce and transport the world’s food. Yet there’s one vital factor even harder to control than panic buying — the weather. A period of extreme weather that devastates harvests could force countries to deploy more protectionist food policies, creating a ripple effect through global trade. Concerns over access to wheat and other staples have already led nations including Kazakhstan and Russia to introduce export restrictions, sparking fears of a global food crisis not seen for a decade. So far the curbs have been limited to a handful of nations imposing short-term measures.

There is a cause for concern. Drier weather has affected key growing regions in the Black Sea, Argentina and across Europe. Behind the day-to-day weather concerns, global warming is playing an ever-greater role in determining the strength of food supplies. The threat of extreme drought or torrential downpours only makes it more difficult to predict what will happen.

“Climate change is the elephant in the room in all these discussions,” said Tim Benton, research director in emerging risks at Chatham House in London and a food security expert. “You can easily imagine some nasty weather happening somewhere around the world which will compound these issues. So let’s just pray for good weather.”

For now, supplies are ample and nobody’s talking about any harvest failures. Yet the threat remains that the situation could quickly shift from being comfortable to dire.