New research has concluded that global warming is helping pests and diseases that attack crops to spread around the world.
Scientists at two British universities found that as regions warm crop pests are moving towards the north and south poles at a rate of 3km a year, the BBC reports. The research is published in the journal Nature Climate Change.
The researchers, from the universities of Exeter and Oxford, says the pests are spreading out from the equator towards the North and South Poles; establishing in areas that were once too cold for them to live in.
Currently, it is estimated that between 10% and 16% of the world's crops are lost to disease outbreaks. The researchers warn that rising global temperatures could make the problem worse.
Lead study author, Dr Dan Bebber, from the University of Exeter, says: "Global food security is one of the major challenges we are going to face over the next few decades.
To investigate the problem, the researchers looked at the records of 612 crop pests and pathogens from around the world that had been collected over the past 50 years, the BBC says.
These included fungi, such as wheat rust, which is devastating harvests in Africa, the Middle East and Asia; insects such as the mountain pine beetle that is destroying trees in the US; as well as bacteria, viruses and microscopic nematode worms.
Each organism's distribution was different - some butterflies and insects are shifting quickly, at about 20km a year; other bacterium species have hardly moved. On average, however, the pests have been spreading by 3.2km each year since 1960.
The researchers believe that the global trade in crops is mainly responsible for the movement of pests and pathogens from country to country. However, the organisms can only take hold in new areas if the conditions are suitable, and the researchers believe that warming temperatures have enabled the creature to survive at higher latitudes.
Dr Bebber says the "most convincing hypothesis" is that global warming has caused this shift.