Climate change is sure to play spoilsport with weather patterns and seasons. We have already seen seasons turning erratic. Some recent studies show that an outbreak of pestilence could be an unforeseen consequence of climate change.
In recent months, a large number of mice has been ravaging Australia’s southern and eastern agricultural regions, and the damage to crops, according to New South Wales Farmers, is expected to touch A$1 billion. Steven Belmain, ecologist & agricultural pest expert, Natural Resources Institute, University of Greenwich, attributes much of the plague to climate-related and agricultural factors. “Usually, you’d have a dry season with minimal vegetation, which would collapse the rodent population,” says Belmain. “But this year, rains have continued into the following season.”
The repeated outbreaks of pests point to the fact that climate change is not just a phenomenon that brings about higher annual temperatures and extreme weather; its consequences ripple outward and are felt most acutely by countries grappling with political instability, poor governance and limited financial resources.
There are over 60 known rodent-transmitted diseases and most of them are becoming resistant to available treatments. “We’re most concerned that the perfect environment for disease emergence is being created because of the interactions of abnormal weather patterns, rodent outbreaks and the spread of diseases like leptospirosis, bubonic plague and lassa fever,” adds Belmain.
In recent years, there have been outbreaks of rodent-transmitted, antibiotic-resistant plague in Madagascar. Though they have been controlled, Belmain feels that the control gets harder when the rodent population gets larger.
Increased numbers of cyclones create ideal conditions for insect-pest outbreaks. In May 2018, an unusually powerful cyclone, Mekunu, made landfall over the Arabian Peninsula before crossing over Oman, bringing heavy rainfall all the way to Saudi Arabia. The warm, sandy and wet soils were the perfect conditions for desert locusts to hatch. Usually after wet periods, dry conditions kill off locusts, but cyclone Luban followed in October 2018. Then, at the end of 2019, yet another, Pawan, carried the locusts across to East Africa, where they caused huge crop damages in East Africa.
Experts believe that such events are likely to increase in the coming years. “The increased cyclone frequency and more extreme climate variability could increase the likelihood of pest outbreaks and spread, adding compromised food security to the consequences of storms themselves,” writes Nature Climate Change. “There’s a real issue of prediction and resource allocation coming as pests move around the world,” explains Belmain. Research has shown that, since 1960, crop pests and vector-borne diseases have been moving to the earth’s poles at 3 km per year as temperature rises.