Without dramatic reductions in greenhouse-gas emissions, most of the planet’s land-based ecosystems — from its forests and grasslands to the deserts and tundra — are at high risk of “major transformation” due to climate change, according to a new study from an international research team.
The researchers used fossil records of global vegetation change that occurred during a period of post-glacial warming to project the magnitude of ecosystem transformations likely in the future under various greenhouse gas emissions scenarios.
They found that under a “business as usual” emissions scenario, in which little is done to rein in heat-trapping greenhouse-gas emissions, vegetation changes across the planet’s wild landscapes will likely be more far-reaching and disruptive than earlier studies suggested.
The changes would threaten global biodiversity and derail vital services that nature provides to humanity, such as water security, carbon storage and recreation, according to study co-author Jonathan Overpeck, dean of the School for Environment and Sustainability at the University of Michigan.
“If we allow climate change to go unchecked, the vegetation of this planet is going to look completely different than it does today, and that means a huge risk to the diversity of the planet,” said Overpeck, who conceived the idea for the study with corresponding author Stephen T. Jackson of the U.S. Geological Survey.
The findings are scheduled for publication in the Aug. 31 edition of the journal Science. Forty-two researchers from around the world contributed to the paper. The first author is geosciences graduate student Connor Nolan of the University of Arizona.
Overpeck stressed that the team’s results are not merely hypothetical. Some of the expected vegetational changes are already underway in places like the American West and Southwest, where forest dieback and massive wildfires are transforming landscapes.
“We’re talking about global landscape change that is ubiquitous and dramatic,” Overpeck said. “And we’re already starting to see it in the United States, as well as around the globe.”
Previous studies based largely on computer modeling and present-day observations also predicted sweeping vegetational changes in response to climate warming due to the ongoing buildup of carbon dioxide and other greenhouse gases.
Read more at University of Michigan