How Will Climate Change Affect Pests?

The projected impacts of climate change on food stability and crop yields are already well-documented problems; scientists believe that we can expect to produce roughly 5% less for every 1°C rise in the global temperature. However, such forecasts fail to take into account the effect that climate change could have on pests – and the knock-on effect that might have on food production.

A new report from universities in the United States estimates that the rising temperatures will cause insects and other unwanted pests to use more energy and procreate more, all of which will result in them consuming between 5% and 10% more of foodstuffs such as maize, rice and wheat. With those three cereals accounting for over 42% of all of the calories consumed worldwide, pests could pose a real conundrum in the future.

Alarming results

The study was carried out by Professor Curtis Deutsch of the University of Washington and was published in the journal Science late last month. In it, Professor Deutsch and his colleagues assessed how the eating and breeding habits of 38 insect species across the world might be affected if climate change is allowed to continue unabated.

They then processed this information through a mathematical model to determine how it would affect the consumption of the three aforementioned cereals. They concluded that insects would be eating anywhere between 10% and 25% more of the cereals for every degree of global warming, which could mean that crop yield decreases could double. In a world which already struggles to feed its entire population, that news is alarming indeed.

Who’s at risk?

The study’s analysis of complex environmental matrices holds most concern for those living in temperature climates, such as much of the USA and Europe. Indeed, many European nations may see the impact of pests on crop yields rise by between 50% and 100%, leading to a loss of as much as 16 million tons of wheat.

Elsewhere, in regions which are already hot all year round, the effects may be less pronounced and in some cases, could actually have the opposite impact. That’s because in tropical countries, insects are already close to acting at their full potential with current temperatures, so any future increases could mean that their populations suffer. This would result in fewer crops being eaten by them.

What’s to be done?

When it comes to tackling the problem, the authors of the study believe a multi-faceted approach is best. “If we don't do some forward-thinking on this we are going to see real impacts on food insecurity.” explained Scott Merrill, co-author of the report. “When we're dealing with pests it shouldn't be 'let's just try for a silver bullet', but more of an integrated strategy using a lot of different tactics.”

Some methods which may work to alleviate the problem include switching to biological instead of chemical pesticides, adapting farming methods to trap carbon, planting more climate- and pest-resistant crops and moving around sowing dates within the calendar year. Of course, limiting climate change as much as is possible by reducing our carbon footprint is also a key method of minimising the impact that pests might have on food security in the future.