Human activity has released several types of gases into the atmosphere that have made our planet heat up. This rise in temperatures threatens the survival of mankind in several ways, a critical threat being an increase in insect populations. The rise of insects will lead to a decrease in food resources and an increase in diseases that could jointly threaten the human race.
Each year, our planet gets hotter. This worrying trend is because of global warming, wherein the overall temperature of Earth’s atmosphere increases due to the release of toxic gasses like carbon dioxide and CFCs. Unfortunately, the root cause of global warming is humans, as we have released massive quantities of heat-trapping gases into the atmosphere to power our lives and industries. As a result, our glaciers are melting, sea levels are rising, ecosystems are dying, and wildlife is perishing at an alarming rate.
The threat of global warming and climate change on the survival of mankind is a very real concern. Scientists are loudly warning us to prepare ourselves for the coming years, which could be catastrophic in a variety of ways. While some warn about rising seas levels, others warn about rising insect populations!
Why should we be so worried about insects?
Insects are likely to be more affected by climate change because climate strongly influences their growth, reproduction and survival. As insects have shorter gestation periods and greater reproductive rates, they respond faster to changes in the climate than other organisms. In fact, researchers have found that many insect species have adapted to warmer habitats throughout history, which has enabled them to grow and thrive faster.
How do global warming and climate change contribute to the rise of insects?
Global warming and climate change can influence the spread of insects in many ways. For starters, warmer temperatures increase the metabolic rates of insects and their populations.
As winters become warmer, insect “winterkills” will reduce. This means that insects will survive longer each year, and the longer they survive, the more they will spread. Changes in climates can also alter the frequency, extent and intensity of insect outbreaks worldwide. For instance, outbreaks of the western hemlock looper (Lambdina fiscellaria lugubrosa Hulst) coincided with lower precipitation levels and higher temperatures in British Colombia.
Similarly, changes in temperature will also bring about range shifts in insects, meaning that insects will spread and colonize newer regions much faster than other wildlife species. In some regions, increasing temperatures have already led to the northward migration of several insect species.
How will the rise of insects affect humans?
The increase of certain insects, such as butterflies, may be welcomed by humans, but the increase of others, such as mosquitoes, may not be as widely appreciated!
Unfortunately, to date, only a few studies have investigated the impact of increasing temperatures on different insect species. Even fewer studies have provided information on how this will impact human populations.
Below are two major concerns of rising insect populations.
Reduced food resources
A recent study reported that insect populations in warmer countries are likely to increase exponentially, as they have higher metabolic and reproductive rates. The increase in insects will consequently have disproportionate effects, with some regions facing more problems than others. For instance, the United States and China, who produce large quantities of maize, will experience widespread crop losses from insect pests. While the insects will have more than enough to feed on, there will likely be rampant food shortages for humans.
This rapid increase in crop destruction will come as a surprise to farmers, and they will need to adapt quickly to these changes. Thus, agricultural practices will shift to cope with changing climates. Famers will likely alter their cropping patterns and use more pesticides, which can have severe consequences on human health.
Spread of disease
Another cause of concern is the rise of insect-borne diseases. While scientists, in general, agree that there will be an increase in insect-borne diseases, the rate, extent, conditions, and consequences remain uncertain.
Between 2004 and 2016, the Centers for Disease Control and Prevention (CDC) reported 642,602 incidents in which diseases caused by bacteria, viruses and parasites were transmitted by mosquitos, fleas or ticks. While the study does not explicitly identify climate change as the cause of disease spread, experts generally agree that the changing climate has a major influence.
An article by The Washington Post draws many connections between climate change and disease spread, as reported by the CDC. For instance, the article highlights that ticks and mosquitos flourish in hotter climates, suggesting that humans will be prone to greater interactions with these insects over extended time periods.
Warmer temperatures also make mosquitoes faster and can make them more infectious. Diseases like malaria and dengue are predicted to increase as a result of booming insect populations. Thus, two things have become apparent this century: climate influences the distribution of insect-borne diseases and weather controls the intensity and timing of outbreaks.
Similarly, the rise in sea levels is also predicted to increase insect-borne diseases. Researchers suggest that the expansion of saltwater into coastal cities can increase mosquito densities and make freshwater mosquito vectors more tolerant towards increasing salinity. This will create new grounds for the spread and growth of insects, along with the diseases they bear.
It is clearly evident that insect numbers will rise due to global warming and climate change. Humans will undoubtedly be affected by this, but to what extent and in what ways… only time will tell.
- Pennsylvania State University
- Centers for Disease Control and Prevention
- The Washington Post
- Bulletin of the American Meteorological Society
- Frontiers in physiology