Release of Carbon from Melting Permafrost Could Trigger Rapid Warming
A study published last week in Nature Geoscience provides the first measurements of greenhouse gases from permafrost under Arctic lakes in Alaska, Siberia, and Canada. Although the research reveals that only a small amount of old carbon has been released in the past 60 years, it also suggests that much more could be released as the Arctic warms up faster than any other place on Earth.
"It's a lit fuse, but the length of that fuse is very long," said lead author Katey Walter Anthony of the University of Alaska. "According to the model projections, we're getting ready for the part where it starts to explode. But it hasn't happened yet."
The scientists determined that the permafrost-carbon feedback is thus far small by looking at aerial photographs and using radiocarbon dating to determine the age of methane emitted from the Arctic lakes that are expanding to consume and thaw terrestrial permafrost. As that permafrost melts and decomposes, it releases ancient carbon as carbon dioxide and methane. Analysis of 113 radiocarbon dating measurements and 289 soil organic carbon measurements showed that approximately 0.2 to 2.5 petagrams of permafrost carbon was released as methane and carbon dioxide in the past six decades.
The billions of tons of carbon stored in permafrost are approximately double the amount currently in the atmosphere. Many researchers are concerned that emission of that stored carbon will contribute to warming that then contributes to permafrost thawing in an accelerating feedback loop.
NASA: Temperature Reconstructions Suggest Achievement of Paris Agreement Goals "Unlikely"
The Paris Agreement's goal to limit Earth's temperature increase to "well below" 2 degrees Celsius and to pursue efforts to limit that increase to 1.5 degrees Celsius above pre-industrial levels is unlikely to be achieved according to temperature reconstructions from the National Oceanic and Atmospheric Administration and the National Aeronautical and Space Administration (NASA). Those reconstructions reveal that the world is heating up faster than at any other time within the past 1,000 years. Over the next 100 years, according to NASA, it will continue to warm at least 20 times faster than the historical average.
"In the last 30 years we've really moved into exceptional territory," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies. "It's unprecedented in 1,000 years. There's no period that has the trend seen in the 20th century in terms of the inclination (of temperatures). Maintaining temperatures below the 1.5C guardrail requires significant and very rapid cuts in carbon dioxide emissions or coordinated geo-engineering. That is very unlikely. We are not even yet making emissions cuts commensurate with keeping warming below 2C."
Using evidence left in tree rings, layers of ice in glaciers, ocean sediments, coral reefs, and layers of sedimentary rocks, NASA figures that the past century's warming of 0.7 degrees Celsius is roughly 10 times faster than the average rate of ice-age-recovery warming.
This year, the average global temperature reached 1.38 Celsius above levels observed in the 19th century, just 0.12 Celsius below the 1.5 Celsius limit that nations aimed for in the Paris Agreement.
Climate Change Major Focus at G20 Summit
Climate change is among the topics world leaders are expected to discuss at a G20 summit in China, beginning September 4.
"This is the first time that the G20 leaders are gathering to discuss the Sustainable Development Goals and climate change, (and) how we implement them in parallel," said United Nations Secretary-General Ban Ki Moon.
President Obama, who began his 10-day trip to Asia on Wednesday, is expected to stress the urgency of climate change. And some media outlets are reporting that the United States and China are expected to announce their ratification of the Paris Agreement prior to the start of the G20 Summit, but the White House has made no formal statement to this effect.
"We've made the commitment that we will join in 2016. And we've made the commitment to do that as soon as possible this year," said Brian Deese, senior advisor to the president. "With respect to exactly when, I don't have any announcements on that front. But we've committed, and we've been working on that issue."
The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University's Nicholas Institute for Environmental Policy Solutions.
In Changing Planet
Tags Tim Profeta
Tim Profeta is the founding director of the Nicholas Institute for Environmental Policy Solutions. The Nicholas Institute is part of Duke University and focuses on improving environmental policy making worldwide through objective, fact-based research in the areas of climate change, the economics of limiting carbon pollution, oceans governance and coastal management, emerging environmental markets and freshwater concerns at home and abroad. In his role at the Nicholas Institute, Profeta has continued to use his experience on Capitol Hill to engage in climate change debates. His research has focused, specifically, on market-based approaches to environmental regulations—particularly energy and climate change policy. Other projects engage his expertise in environmental law and air pollution regulation under the Clean Air Act.
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