The global insect population outweighs all of humanity by a margin of 17 to 1, but humans are on track to wipe insects out in a matter of decades, according to the first worldwide review of insect decline.
This would be doubly catastrophic. First, losing the insects means losing the animals that feed on them, thus shattering the entire ecosystem. Second, losing the insects — which pollinate plants and keep the soil healthy — would devastate agriculture and our ability to feed a rapidly growing population.
“Unless we change our way of producing food, insects as a whole will go down the path of extinction in a few decades,” the alarming new study in the journal Biological Conservation warns.
The Australian researchers reviewed 73 historical reports of insect decline worldwide to understand the underlying drivers. They found “dramatic rates of decline that may lead to the extinction of 40 percent of the world’s insect species over the next few decades.”
The cause? Human-driven habitat loss, pollution, and climate change.
Every year, another 1 percent of insect species joins the ranks of those endangered. As a result, the biomass, or total combined weight, of all insects is dropping by some 2.5 percent globally each year.
In short, about every two years, we lose enough insects to balance the scales with the total weight of every living human being.
At the current pace of extinction, “in 50 years only half [of insects will be] left and in 100 years you will have none,” lead author Francisco Sánchez-Bayo of the University of Sydney told the UK Guardian.
Equally disturbing is the fact that the insects that are most endangered — ants, bees, butterflies, dragonflies, and dung beetles — are integral to both the overall ecosystem and agriculture. They pollinate food and keep the soil healthy.
“If we destroy the basis of the ecosystem, which are the insects, then we destroy all the other animals that rely on them for a food source,” Sánchez-Bayo explained in a press release.
Humans, of course, rely on the ecosystem — and especially insects — to sustain our modern system of farming and feed a global population that is nearing 8 billion and headed toward 10 billion by mid century.
That’s why it’s so tragic that human activity, including modern industrial agriculture, is to blame for this collapse, according to the study.
The researchers found that the primary causes of global insect collapse are habitat destruction — driven largely by modern industrial agriculture — pesticides, pollution, and climate change.
“The chief driver of this catastrophe is unchecked human greed,” as the UK Guardian editorialized.
Human-caused climate change is a major contributor to insect loss in the tropics. An October study found that global warming helped cause a remarkable 98 percent decline in Puerto Rico’s tropical rainforest insect population between 1976 and 2013.
A 2014 review of scientific literature and data in the journal Science found that the number of insects “such as beetles, butterflies, spiders and worms has decreased by 45 percent” since 1980. The cause? Researchers again pointed to “loss of habitat and global climate disruption.”
Besides a reduction in pollution, the new study concludes we urgently need “a serious reduction in pesticide usage and its substitution with more sustainable, ecologically-based practice.”
The researchers are clear that failing to act will have tremendous consequences. “If insect species losses cannot be halted,” warns Sánchez-Bayo, “this will have catastrophic consequences for both the planet’s ecosystems and for the survival of mankind.”
We’ve met the enemy, and they are us.