With increasing global temperature, climate change repercussions have become more visible in recent years. Our agricultural productivity and net output could reduce drastically owing to warmer conditions which create a favourable environment for pests such as fungi, insects and bacteria. This would mean an additional threat to food security for millions who are already facing challenges as a result of booming population and uncertain weather conditions like floods, heat waves and drought. Those who are already struggling with poverty and have no resources to adapt to or mitigate climate change implications would be most vulnerable to crop yield losses due to expanding pests and diseases.
Most of these pests like ticks and crop insects are cold-blooded or ectothermal creatures and any variation in external temperature may shift their behaviour, distribution, reproduction patterns and survival. The high temperatures and humid condition may favour these pests. Climate change is expected to change the activities of the pests in two ways. One, their food consumption rate will increase; as the rising temperature enhances their digestion rate, they can wipe out the crops at a much rapid rate than they do in the lower temperature. Second, their population growth will increase; as they become more active in higher temperature, they will reproduce more often.
As the number of pests and their appetite grow in higher temperature condition, the global crop production is at greater risk. At present, pests cause somewhere 10 to 16 per cent loss in crop yields. Invertebrates like ticks flourish in warmer and longer summers. If we do not control our global carbon emission and let the temperature soar and increase by 2 degree Celsius since pre-industrial period, we might witness a considerable loss in the production of most popular grains worldwide. It is expected that the production of wheat, rice and maize will reduce by 46%, 19% and 31% respectively. Some of the largest grain producers of the world like the United States, China and France may have the biggest losses in terms of crop yield. Pest like Desert locusts which affect rice, maize and sugarcane can demolish entire fields within an hour; rootworms which feed on maize in its different life stages results in an annual loss of USD 1 billion. In the tropics, where rice is grown, it will have a small decline in the population of some pests as tropics already have an optimal temperature for insects to reproduce and any further rise in temperature will be unfavourable. Some of the most productive regions in the world, the wheat-growing regions of Europe may incur huge losses. Nations like the United Kingdom, Sweden and Ireland may lose up to 75 per cent productivity due to insect-related infestations and diseases. Even in Sub-Saharan Africa and in Southeast Asia, which already face poverty and hunger, there are chances of moderate losses too.
We will need a comprehensive adaptive and mitigation strategies to tackle climate change challenges to ensure our food security. An urgent and immediate plan of action is needed with involvement from industries, policymakers, farmers and people in general. With integrated management of pests and diseases and more focus on plant protection, these threats will result in lesser damages.