Study warns of global ecosystem collapse

Alpine tundra and valleys of temperate rainforests in Australia
Alpine tundra and valleys of temperate rainforests in SW Tasmania

A new study co-authored by a Portland State researcher is sounding the alarm on global ecosystem collapse if action is not taken urgently.

The study, authored by 38 researchers from Australia, the United Kingdom and the U.S., including PSU geography professor Andrés Holz, examines the current state and recent trajectories of 19 ecosystems extending from northern Australia to coastal Antarctica, which is roughly the equivalent to the distance from Florida to the Arctic. These ecosystems cover about 1.5% of the Earth's surface and range from deserts to mountains and rainforests, freshwater and marine biomes.

The researchers say ecosystem collapse is driven by different pressures —- chronic stresses like climate trends, habitat loss, invasive species and pollution or acute effects like storms, heatwaves and wildfires. They say pressures have become more severe, widespread and more frequent, and all 19 ecosystems showed some level of collapse.

Holz, the only U.S.-based researcher, said Oregon has similar types of ecosystems to the ones studied and the findings offer a word of warning, especially around warmer temperatures, drought, reduced snowpack and heavier precipitation. 

"We're not yet at the level that the paper shows in Australia, but we're moving in that direction," he said. "We're in the queue to get very rapidly transforming stresses to our way of life, to the way our ecosystems function. We still have a chance to get our act together."

He pointed to the Fifth Oregon Climate Assessment — a biennial assessment of the state of climate change science and the likely effects of climate change on Oregon that several PSU faculty members contributed to — which lays out some of those changes such as the frequency of extreme heat events, droughts, wildfires and floods.

"Some of them are rapid, some of them are slower, but it's mostly pointing to changes that are weakening ecosystems," Holz said.

The Australian study recommends a new '3A' framework to guide decision-making about actions to combat irreversible damage:

  1. Awareness of the importance of the ecosystem and the need for its protection
  2. Anticipation of the risks from current and future pressures
  3. Action on reducing the pressures to avoid or lessen their impacts

The study was published in the journal Global Change Biology.