SUBSCRIBE TO OUR FREE NEWSLETTER
Daily news & progressive opinion—funded by the people, not the corporations—delivered straight to your inbox.
5
#000000
#FFFFFF
5
#000000
#FFFFFF
permafrost
'We Need Urgent Global Action': Study Warns Humanity on Path to Trigger 16 Climate Tipping Points
Climate scholars use the term "tipping point" to describe a critical threshold which, when crossed, "leads to significant and long-term changes of the system," the paper notes. Debate over it "has intensified over the past two decades," prompting several studies of specific risks.
"Climate tipping points could have devastating consequences for humanity," said co-author Tim Lenton in a statement. "It is clear that we are currently on a dangerous trajectory—with tipping points likely to be triggered unless we change course rapidly."
"We need urgent global action—including the triggering of 'positive tipping points' in our societies and economies—to reach a safe and sustainable future," added the Exeter professor and Global Systems Institute director.
Lenton's team calculated the probabilities of triggering 16 tipping points. They looked at the risks of serious damage to key glaciers, ice sheets, sea ice, and permafrost; the dieback of forests such as the Amazon; the die-off of low-latitute coral reefs; and the collapse of the Atlantic Meridional Overturning Circulation (AMOC), which is part of a crucial "global conveyor belt" of ocean currents.
To assess the risk of current policies triggering climate tipping points, the researchers focused on a scenario in which median warming of 2.8°C takes place by the end of the century.
On that pathway, the study says, "our most conservative estimate of triggering probabilities averaged over all tipping points is 62%... and nine tipping points have a more than 50% probability of getting triggered."
Under scenarios with lower temperature rise, "the risk of triggering climate tipping points is reduced significantly," the study continues. "However, it also remains less constrained since the behaviour of climate tipping points in the case of a temperature overshoot is still highly uncertain."
The paper concludes that "rapid action is needed to reduce greenhouse gas emissions, since climate tipping points are already close, and it will be decided within the coming decades if they will be crossed or not."
Lead author Jakob Deutloff shared that takeaway a bit more optimistically, saying that "the good news from our study is that the power to prevent climate tipping points is still in our hands."
"By moving towards a more sustainable future with lower emissions, the risk of triggering these tipping points is significantly reduced," he added. "And it appears that breaching tipping points within the Amazon and the permafrost region should not necessarily trigger others."
The paper was published during Covering Climate Now's joint week of media coverage drawing attention to the 89% of people worldwide who want their governments to do more to address the global crisis; ahead of a Global Systems Institute conference on tipping points this summer; and just over six months away from the next United Nations climate summit, COP30, in Brazil.
While some governments are trying to prevent the worst-case scenario by taking action to cut emissions, U.S. President Donald Trump has made clear since returning to office in January that he aims to deliver on his pro-fossil fuel campaign pledge to "drill, baby, drill."
On the heels of the
hottest year in human history, Trump is working to gut key agencies, ditched the Paris climate agreement, and has taken executive action to boost planet-wrecking coal, gas, and oil, including declaring a national energy emergency.
Scientists Find Craters--Including One Bigger Than a City Block--in Arctic Seafloor
An international team of researchers led by Charlie Paull, a geologist at the Monterey Bay Aquarium Research Institute in California, and Scott Dallimore of the Geological Survey of Canada published their findings in the peer-reviewed journal Proceedings of the National Academy of Sciences (PNAS).
Permafrost is a mix of ice, rocks, sand, and soil that remains frozen year-round. The thawing of terrestrial permafrost in places like Siberia has fueled concerns about not only damage to at-risk infrastructure but also the release of planet-heating gases as well as ancient bacteria and viruses.
However, Paull and Dallimore's team analyzed changes in the permafrost that lies beneath Arctic waters. Specifically, they focused on 10 square miles of the Canadian Beaufort Sea, using underwater vehicle and ship-mounted sonar for surveys of the seafloor in 2010, 2013, 2017, and 2019.
The researchers found craters--including one that was 92 feet deep, 738 feet long, and 312 feet wide, or bigger than a city block of six-story buildings--as well as ice-cored hills resembling "pingos" previously documented on land.
"We know that big changes are happening across the Arctic landscape, but this is the first time we've been able to deploy technology to see that changes are happening offshore too," Paull noted in a statement Monday.
Unlike terrestrial permafrost thawing, the limited data available signals that human-caused global heating is not "driving the dramatic changes in the seafloor terrain," Paull explained. "Instead, heat carried in slowly moving groundwater systems is driving these changes."
Though the team connected the seafloor changes to climatic shifts related to the planet's emergence from the last ice age nearly 12,000 ago, Paull stressed that research like his first-of-its-kind study are important in an era of rising temperatures from human activities like burning fossil fuels.
"While the underwater sinkholes we have discovered are the result of longer-term, glacial-interglacial climate cycles, we know the Arctic is warming faster than any region on Earth," he said. "As climate change continues to reshape the Arctic, it's critical that we also understand changes in the submerged permafrost offshore."
Sue Natali, Arctic Program Director and senior scientist at the Woodwell Climate Research Center in Massachusetts--who was not involved in the study--made a similar point to CNN on Monday.
"Changes described in this study are responding to events that occurred over the centennial to millennial time frame. That said, these changes can still impact climate if they are resulting in emissions of greenhouse gases as the subsea permafrost thaws," she explained.
Related Content
'A Real Hotspot': Study Shows Arctic Warming 3 Times Faster Than Rest of Earth
The underwater research was released the same day as multiple studies on terrestrial permafrost. One paper, published in the journal Nature Communications, found that alpine permafrost is expected to melt at a faster rate than Arctic permafrost under current conditions.
"Our findings were very surprising and highlight the fact that we need to put more effort into monitoring the stability of the permafrost in the alpine region," said lead author Feng Cheng of China's Peking University.
Paper co-author Carmala Garzione, dean of the University of Arizona College of Science, agreed. As she put it:
We need better and broader studies of the vulnerability of alpine regions under global warming scenarios. There's been a lot of focus on the stability of Arctic permafrost, because it covers more land area and contains a huge reservoir of organic carbon trapped in permafrost, but we also need to be aware that alpine regions stand to lose more permafrost proportionally and are important in understanding of potential carbon release under global warming scenarios.
Another study, published in the journal Nature Climate Change, warned that peatlands in Europe and Western Siberia--which store up to 39 billion tons of carbon--are closer to a climatic tipping point than previously thought.
"Our modeling shows that these fragile ecosystems are on a precipice and even moderate mitigation leads to the widespread loss of suitable climates for peat permafrost by the end of the century," said lead author Richard Fewster of the University of Leeds in the United Kingdom.
"But that doesn't mean we should throw in the towel," he said. "The rate and extent to which suitable climate are lost could be limited, and even partially reversed, by strong climate change mitigation policies."
New Climate Study Predicting More Rain Than Snow in the Arctic 'Rings Alarm Bells'
"As the Arctic continues to warm faster than the rest of the planet, evidence mounts that the region is experiencing unprecedented environmental change," says the study, spearheaded by Michelle McCrystall, a postdoctoral fellow at the University of Manitoba.
"The transition from a snow- to rain-dominated Arctic in the summer and autumn is projected to occur decades earlier and at a lower level of global warming, potentially under 1.5degC, with profound climatic, ecosystem, and socioeconomic impacts," the paper continues, referencing the Paris climate agreement's lower temperature target for the end of this century.
McCrystall detailed the anticipated consequences of this transition, which is happening because of rapid global heating, poleward moisture transport, greater Arctic amplification, sea-ice loss, and increased sensitivity of precipitation to regional warming.
"People might say, 'Well, what has that got to do with me?' Well, this is going to affect you, and in actual fact, it is affecting you now," McCrystall said in a statement. "For me, I think what people need to understand is, we live in a global society where everything is interconnected, and that's true of the climate. We have a global climate. So, what happens in one region, will affect what happens everywhere else."
Related Content
'Unsettling': New Study Reveals Arctic Ocean Warming for Over a Century
"There are huge ramifications of these changes, which we note in the paper, such as a reduction of snow cover, increased permafrost melt, more rain-on-snow events, and greater flooding events from increased river discharge, all of which have implications on wildlife populations and human livelihoods," the lead researcher explained.
Her team was finalizing their paper this year when, in August, rain fell on the highest point of the Greenland ice sheet for the first time in recorded history.
"The fact that we're getting rainfall on the summit of Greenland right now, and that we're maybe going to get more rainfall into the future--it kind of staggers me," she said. "And when we talk about this happening in 2100, it seems like such a long time away, but it's only 80 years. That's the next generation. And if we continue the trajectory that we're going, a lot of issues might happen even faster than what we've projected."
As co-author James Screen at the University of Exeter put it: "The new models couldn't be clearer that unless global warming is stopped, the future Arctic will be wetter; once-frozen seas will be open water, rain will replace snow."
In addition to reducing snow cover--which will further exacerbate warming in the region and globally--the shift to more rain will impact soil moisture and groundwater "as well as flora, fauna, and linked social-ecological systems."
While the researchers expect migratory birds to do well with the changing conditions, increased rainfall could have a "devastating" impact on wild caribou, reindeer, and muskoxen populations.
"The issue facing us today is that the Arctic is changing so fast that Arctic wildlife might not be able to adapt," said co-author Mark Serreze, director of the United States' National Snow and Ice Data Center. "It's not just a problem for the reindeer, caribou, and muskox, but for the people of the North that depend on them as well."
Gavin Schmidt, director of the NASA Goddard Institute for Space Studies, told Agence France-Presse that he felt the study did not prove the rain shift would come earlier than expected, but also said its results "imply that the worst impacts can be avoided if countries match their stated intentions to cut emissions in line with the Paris agreement."
As Common Dreams reported earlier this month, during the COP26 climate summit in Scotland, a recent analysis found that even if countries meet their emissions targets for this decade, the global temperature could still climb to 2.4degC above pre-industrial levels by 2100.
Richard Allan at the U.K.'s University of Reading--who, like NASA's Schmidt, was not involved in the research--framed the findings about Arctic rainfall as an urgent warning to humanity.
"Exploiting a state-of-the-art set of complex computer simulations, this new study paints a worrying picture of future Arctic climate change that is more rapid and substantial than previously thought," he told The Guardian. "This research rings alarm bells for the Arctic and beyond."
Most Popular