Climate Change Is Not The ‘Biggest Killer’ Of Biodiversity

Global climate change, including sea-level rise, drought and extreme heat, is no doubt taking a toll on our planet ― but it’s far from the biggest threat humans have imposed on Earth’s plant and animal species.

A new analysis of threatened wildlife has provided a much-needed dose of perspective, showing that age-old human activities, including logging, hunting and farming, continue to pose a greater and more urgent threat.

Despite a “growing tendency for media reports about threats to biodiversity to focus on climate change,” over-exploitation and agriculture are “by far the biggest drivers of biodiversity decline,” the authors write in a comment published Wednesday in the journal Nature.

For the report, a team of scientists led by Sean Maxwell, a doctoral student at the University of Queensland, analyzed thousands of species on the International Union for Conservation of Nature’s Red List of Threatened Species.

The group found that over-exploitation, including logging, hunting, fishing and the gathering of plants, tops the list of biodiversity’s “biggest killers,” affecting 72 percent of the 8,688 species listed by IUCN as threatened or near-threatened. Agricultural activity impacts 62 percent of those species, while urban development and pollution threaten 35 and 22 percent, respectively.

Somewhat surprisingly, climate change ranked seventh of the 11 threats studied. Its effects ― including sea-level rise, extreme temperatures, storms and drought ― currently threaten 19 percent of those 8,000-plus species, according to the findings. 

Addressing “old foes,” Maxwell said in a statement, will be “key to turning around the biodiversity extinction crisis.”

Maxwell did not immediately respond to The Huffington Post’s request for comment.

Researchers said Africa’s cheetah and Asia’s hairy-nosed otter are among the 5,407 species affected by agricultural practices, while illegal hunting continues to deplete numerous populations, including the Sumatran rhinoceros and Western gorilla. Some 100 African elephants are killed each day by poachers, often for nothing more than their tusks.

One of the 1,688 species directly affected by climate change is the hooded seal, which the report says has seen populations decline by 90 percent in the northeastern Atlantic Arctic over the last several decades, mainly as a result of declining sea ice.

Not specifically mentioned in the analysis are corals, which have become a kind of poster child for climate change. Coral reefs have been devastated by the “longest and most widespread“ bleaching event on record, a phenomenon in which stressed corals expel algae and turn white, often as a result of warming ocean temperatures.

Thomas Brooks, a co-author of the report and head of IUCN’s science and knowledge unit, told The New Yorker that while addressing climate change remains crucial, there are more immediate threats to the world’s imperiled species.

“If we don’t address them, we’re going to lose most of our biodiversity, no matter what we do about climate change,” he told the publication.

The analysis’ release comes just weeks before Hawaii hosts IUCN’s World Conservation Congress, during which thousands of environmental policy-makers from around the world will meet to set conservation priorities.

In the new report, researchers have urged IUCN delegates to focus on prioritizing threats with the greatest impact on species loss.

“Actions such as well managed protected areas, enforcement of hunting regulations, and managing agricultural systems in ways that allow threatened species to persist within them, all have a major role to play in reducing the biodiversity crisis,” James Watson, a report co-author and director of science and research initiative at the Wildlife Conservation Society, said in a statement.