Scientists warn of many dangerous climate feedback loops
Current plans to mitigate climate change may be inadequate
Peer-Reviewed PublicationIMAGE: THE WILDFIRE-CLIMATE CHANGE FEEDBACK LOOP. view more
CREDIT: CHRIS WOLF, WILLIAM RIPPLE BACKGROUND PHOTO BY PETER BUSCHMANN
A new report written by an international team of researchers, including scientists from Oregon State University (OSU), warns of many risky climate feedback loops and the need for action in both research and policy. Published in the scientific journal One Earth today, the report states that partly due to amplifying climate feedbacks, “a very rapid drawdown in emissions will be required to limit future warming.”
Researchers from the United States and Europe listed and described 41 climate feedback loops that have major implications for the outlook on climate change. Climate feedback loops are processes that can either amplify or diminish the effects of our greenhouse gas emissions, initiating a cyclical chain reaction that keeps repeating again and again. There are many large amplifying feedbacks that accentuate warming. In total, the researchers identified 27 amplifying feedbacks, 7 dampening feedbacks, and 7 uncertain feedbacks.
The lead authors, Christopher Wolf, a postdoctoral researcher at OSU, and William Ripple, a distinguished professor of ecology at OSU, were joined by several US and international scientists who are credited as co-authors on the report. Ripple is also an affiliate scientist with the Conservation Biology Institute.
The authors highlight several particularly troubling feedback loops such as the permafrost feedback wherein rising temperatures lead to permafrost thawing, which results in more carbon dioxide and methane emissions, leading to further warming. Other potentially dangerous feedbacks include drying or smoldering peatlands and forest dieback. Because these feedbacks may not yet be fully incorporated into climate models, current emissions drawdown plans could fail to adequately limit future warming. In addition, “some climate feedback loops are associated with tipping points, which will make it difficult to reverse their effects,” said coauthor Jillian Gregg, a scientist at Terrestrial Ecosystems Research Associates.
Motivated by the many amplifying climate feedbacks, the authors make two recommendations. With regard to climate research, a rapid transition toward integrated Earth system science is needed in order to fully account for biological, social, and other interactions that may influence the climate. In terms of climate policy, more ambitious plans for emissions drawdown should be pursued given both ongoing climate disasters and long-term catastrophic risks. Such plans could include employing nature-based solutions to sequester more carbon from the atmosphere. “The strategic establishment of large natural carbon sinks such as forests is a critical step toward reaching carbon neutrality,” said Ripple.
The authors concluded by issuing a call for transformative change to address the climate crisis and dangers posed by feedback loops. According to Wolf, “policies are needed to facilitate transformative and socially just changes across many sectors, including energy and food production.”
The paper is accompanied by the launch of a feedback loops website with animated feedback loops inspired by the study.
In addition to Wolf, Ripple, and Gregg, five other scientists are co-authors of the paper:
Timothy M. Lenton of University of Exeter, Susan M. Natali and Philip B. Duffy of the Woodwell Climate Research Center, Johan Rockström and Hans Joachim Schellnhuber of the Potsdam Institute for Climate Impact Research.
Permafrost
CREDIT
Brandt Meixell, USGS
Sea ice
CREDIT
Patrick Kelley, U.S. Coast Guard
Wildfire
CREDIT
Peter Buschmann
JOURNAL
One Earth
METHOD OF RESEARCH
Meta-analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Scientists warn of many dangerous climate feedback loops
ARTICLE PUBLICATION DATE
17-Feb-2023
Feedback loops make climate action even more urgent, scientists say
IMAGE: FIRE DAMAGE IN THE CITY OF DETROIT, OREGON, AND THE OREGON CASCADES CAN BE SEEN IN THIS AERIAL IMAGE. PHOTO COURTESY OREGON STATE UNIVERSITY. view more
CREDIT: OREGON STATE UNIVERSITY
CORVALLIS, Ore. – An international collaboration led by Oregon State University scientists has identified 27 global warming accelerators known as amplifying feedback loops, including some that the researchers say may not be fully accounted for in climate models.
They note that the findings, published today in the journal One Earth, add urgency to the need to respond to the climate crisis and provide a roadmap for policymakers aiming to avert the most severe consequences of a warming planet.
In climate science, amplifying feedback loops are situations where a climate-caused alteration can trigger a process that causes even more warming, which in turn intensifies the alteration. An example would be warming in the Arctic, leading to melting sea ice, which results in further warming because sea water absorbs rather than reflects solar radiation.
OSU College of Forestry postdoctoral scholar Christopher Wolf and distinguished professor William Ripple led the study, which in all looked at 41 climate change feedbacks.
“Many of the feedback loops we examined significantly increase warming because of their connection to greenhouse gas emissions,” Wolf said. “To the best of our knowledge, this is the most extensive list available of climate feedback loops, and not all of them are fully considered in climate models. What’s urgently needed is more research and modeling and an accelerated cutback of emissions.”
The paper makes two calls to action for “immediate and massive” emissions reductions:
- Minimize short-term warming given that “climate disasters” in the form of wildfires, coastal flooding, permafrost thaw, intense storms and other extreme weather are already occurring.
- Mitigate the possible major threats looming from climate tipping points that are drawing ever-closer due to the prevalence of the many amplifying feedback loops. A tipping point is a threshold after which a change in a component of the climate system becomes self-perpetuating.
“Transformative, socially just changes in global energy and transportation, short-lived air pollution, food production, nature preservation and the international economy, together with population policies based on education and equality, are needed to meet these challenges in both the short and long term,” Ripple said. “It’s too late to fully prevent the pain of climate change, but if we take meaningful steps soon while prioritizing human basic needs and social justice, it could still be possible to limit the harm.”
Ripple, Wolf and co-authors from the University of Exeter, the Potsdam Institute for Climate Impact Research, the Woodwell Climate Research Center and Terrestrial Ecosystems Research Associates considered both biological and physical feedbacks. Biological feedbacks include forest dieback, soil carbon loss and wildfire; physical feedbacks involve changes such as reduced snow cover, increased Antarctic rainfall and shrinking arctic sea ice.
Even comparatively modest warming is expected to heighten the likelihood that the Earth will cross various tipping points, the researchers say, causing big changes in the planet’s climate system and potentially strengthening the amplifying feedbacks.
“Climate models may be underestimating the acceleration in global temperature change because they aren’t fully considering this large and related set of amplifying feedback loops,” Wolf said. “The accuracy of climate models is crucial as they help guide mitigation efforts by telling policymakers about the expected effects of human-caused greenhouse gas emissions. While recent climate models do a much better job of incorporating diverse feedback loops, more progress is needed.”
Emissions have risen substantially over the last century, the researchers note, despite several decades of warnings that they should be significantly curbed. The scientists say interactions among feedback loops could cause a permanent shift away from the Earth’s current climate state to one that threatens the survival of many humans and other life forms.
“In the worst case, if amplifying feedbacks are strong enough, the result is likely tragic climate change that’s moved beyond anything humans can control,” Ripple said. “We need a rapid transition toward integrated Earth system science because the climate can only be fully understood by considering the functioning and state of all Earth systems together. This will require large-scale collaboration, and the result would provide better information for policymakers.”
In addition to the 27 amplifying climate feedbacks the scientists studied were seven that are characterized as dampening – they act to stabilize the climate system. An example is carbon dioxide fertilization, where rising concentrations of atmospheric CO2 lead to increasing carbon uptake by vegetation.
The effects of the remaining seven feedbacks, including increased atmospheric dust and reduced ocean stability, are not yet known.
The paper in One Earth has a corresponding website that features more about climate feedback loops, including infographics and interactive animations.
JOURNAL
One Earth
METHOD OF RESEARCH
Literature review
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Many risky feedback loops amplify the need for massive climate action
ARTICLE PUBLICATION DATE
17-Feb-2023
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