How climate change is fuelling the spread of invasive pests

Due to the impact of climate change, plant pests that ravage economically important crops are becoming more destructive and posing an increasing threat to food security and the environment. International co-operation in fighting this problem is required, according to a scientific review by the International Plant Protection Convention.

Since their domestication approximately 10 000 years ago, crops have been threatened by a multitude of pests that cause yield losses, often leading to starvation and social unrest. On average, between 10% and 28% of crop production worldwide is lost to pests. In addition, each year, plant diseases cost the global economy more than US$220 billion (almost R3 trillion) and invasive insects at least US$70 billion (R950 billion). Post-harvest losses also occur, with the worst of these taking place in developing countries.

Besides losses, the presence of mycotoxins (toxins produced by fungi) in food and feed can severely threaten the health of humans and livestock. There is evidence to suggest that climate change and global warning will facilitate the introduction of unwanted organisms. The key findings of the report, ‘Scientific review of the impact of climate change on plant pests’, sheds light on how climate change may affect how infectious, widely distributed and problematic pests can become around the world. The review clearly shows that the impact of climate change is one of the greatest challenges faced by the plant health community.

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The scientific review finds that climate change will increase the risk of pests spreading in agricultural and forestry ecosystems, especially in cooler Arctic, boreal, temperate and subtropical regions. For example, a single, unusually warm winter may be enough to assist the establishment of invasive pests, which otherwise would not be able to establish themselves. In fact, the increased market globalisation of recent years, coupled with increased temperatures, has led to a situation that is extremely favourable to pest movement and establishment, with concomitant increases in the risk of severe forest and crop impacts.