Feedback loops in climate make a plan to cut emissions even more urgent as they could accelerate climate change
An international team led by scientists at Oregon State University has identified 27 accelerators of global warming known as amplifier feedback loops, including some that researchers say may not be fully accounted for in current climate models. The results, published in Cell One Earth magazine, show the urgency of responding to the climate crisis. On the website accompanying the study, the researchers provide simulators of these feedback loops and provide a roadmap for policymakers to avoid the most serious consequences of global warming.
In climatology, amplification feedback loops are situations where a disturbance caused by the weather can trigger further warming, which in turn intensifies the change. An example would be Arctic warming, which causes sea ice to melt, leading to even greater warming because seawater absorbs solar radiation instead of reflecting it.
In total, the study analyzed 41 climate change feedbacks, of which 27 had an amplifying effect. Many significantly increase warming due to their connection to greenhouse gas emissions. Not all of these feedback loops are accounted for in current climate models, meaning forecasts can be inaccurate.
The document makes two calls to action for an “immediate and massive” reduction in emissions. First, to minimize short-term warming, as climate disasters in the form of wildfires, coastal flooding, permafrost thaw, intense storms and other extreme weather events are already occurring.
On the other hand, mitigating potential threats from climate tipping points, closer and closer precisely due to the many amplification feedback loops. A tipping point is a threshold beyond which a change in a component of the climate system is self-perpetuating.
There are biological and physical feedbacks. The biological ones include the death of forests, the loss of soil carbon and forest fires; the physical, changes such as reduced snow cover, increased precipitation in Antarctica and decreased Arctic sea ice.
According to the researchers, even relatively moderate warming would increase the likelihood that Earth would cross several tipping points, triggering major changes in the planet’s climate system and potentially reinforcing amplifying feedbacks.
In addition to the 27 amplifying climate feedbacks that the scientists studied, there are seven that are characterized as buffers – that is, they act to stabilize the climate system. An example is carbon dioxide fertilization, where increased atmospheric CO2 concentrations cause increased carbon uptake by vegetation. The effects of the remaining seven feedbacks, such as increased atmospheric dust and reduced ocean stability, are not characterized as damping.
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Too many risky feedback loops amplify the need for climate action