Washington: Scientists have identified 27 global warming accelerators known as amplifying feedback loops, including some that researchers say cannot be fully accounted for in climate models.
Scientists say the findings add urgency to the need to respond to the climate crisis.
In climate science, amplifying feedback loops are situations in which climate-induced change can trigger a process that causes more warming, which intensifies the change.
An example would be the warming of the Arctic, which causes sea ice to melt, causing further warming as seawater absorbs rather than reflects solar radiation.
International collaboration led by Oregon State University (OSU), the US, researchers, also provide a roadmap for policymakers aimed at avoiding the most serious consequences of a warming planet, they said.
The findings were published in the journal One Earth.
The study looked at 41 responses to climate change.
“Many of the feedback loops we examined increase warming because of their connection to greenhouse gas emissions,” said OSU College of Forestry postdoctoral scholar and lead researcher Christopher Wolff.
“To the best of our knowledge, this is the most comprehensive list of climate feedback loops available, and not all of them are fully accounted for in climate models. What is urgently needed is more research and modeling and an accelerated cutback in emissions,” said Wolf.
The study considered both biological and physical responses.
Biological responses include forest dieback, loss of soil carbon, and wildfires, while physical responses include changes such as reduced snow cover, increased Antarctic precipitation, and shrinking Arctic sea ice.
Even relatively modest warming is expected to increase the likelihood that Earth will exceed various tipping points, the researchers said, causing major changes in the planet’s climate system and potentially strengthening feedbacks.
“Climate models may underestimate the acceleration of global temperature change because they are not fully accounting for these large and related feedback loops,” Wolf said.
“The accuracy of climate models is critical because they guide mitigation efforts by telling policymakers about the expected impacts of human-caused greenhouse gas emissions.
“While recent climate models do a very good job of incorporating the various feedback loops, more progress is needed,” Wolf said.
Emissions have risen significantly over the past century, the researchers noted, despite decades of warnings that they should be significantly curbed.
Scientists say interactions between feedback loops could lead to a permanent shift from Earth’s current climate that threatens the survival of many people and other life forms.
“We need a rapid shift toward integrated Earth system science because 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 results will provide better information for policymakers,” Ripple said.
The paper calls for two steps to “immediate and massive” emissions reductions:
* Reduce short-term warming as “climate disasters” are already occurring in the form of wildfires, coastal flooding, permafrost patches, severe storms and other extreme weather events.
* Mitigate potential major threats arising from climate tipping points that are steadily approaching due to the proliferation of multiple amplifying feedback loops. A tipping point is a threshold after which change in a component of the climate system becomes self-sustaining.
“Transformative, socially global changes in energy and transport, short-term air pollution, food production, nature conservation and international economics, including population policies based on education and equality, are needed to address these challenges in both the short and long term.” William RippleAnother main researcher Dr.
“It is too late to fully prevent the suffering of climate change, but if we take meaningful action soon while prioritizing basic human needs and social justice, it may still be possible to limit the damage,” Ripple said.
In addition to the 27 amplifying climate feedbacks, the scientists studied seven that were identified as dampeners — they act to stabilize the climate system, the study said.
One example is carbon dioxide fertilization, where increasing concentrations of atmospheric CO2 lead to increased carbon uptake by plants, the study said.
The effects of the remaining seven feedbacks, including increased atmospheric dust and reduced ocean stability, are not yet known, the study said.