Agricultural intensification and climate change are rapidly decreasing insect biodiversity

TLDR

Since the end of World War II, insect biomass and diversity have sharply declined worldwide, driven by climate change and the expansion of industrial agriculture that replaces natural habitats with monocultures, pesticides, and large‑scale cropland, eroding pollinators and pest predators. The study proposes that mitigating the ongoing Sixth Mass Extinction requires stabilizing human population, adopting sustainable consumption, and ensuring social justice that empowers the world's poorer peoples and nations. The authors conclude that the spread and intensification of agriculture over the past fifty years directly drives the observed insect biodiversity losses.

Abstract

Major declines in insect biomass and diversity, reviewed here, have become obvious and well documented since the end of World War II. Here, we conclude that the spread and intensification of agriculture during the past half century is directly related to these losses. In addition, many areas, including tropical mountains, are suffering serious losses because of climate change as well. Crops currently occupy about 11% of the world's land surface, with active grazing taking place over an additional 30%. The industrialization of agriculture during the second half of the 20th century involved farming on greatly expanded scales, monoculturing, the application of increasing amounts of pesticides and fertilizers, and the elimination of interspersed hedgerows and other wildlife habitat fragments, all practices that are destructive to insect and other biodiversity in and near the fields. Some of the insects that we are destroying, including pollinators and predators of crop pests, are directly beneficial to the crops. In the tropics generally, natural vegetation is being destroyed rapidly and often replaced with export crops such as oil palm and soybeans. To mitigate the effects of the Sixth Mass Extinction event that we have caused and are experiencing now, the following will be necessary: a stable (and almost certainly lower) human population, sustainable levels of consumption, and social justice that empowers the less wealthy people and nations of the world, where the vast majority of us live, will be necessary.