Abrupt Impacts of Climate Change: Anticipating Surprises (2013)
National Academy of Sciences
Authors: Committee on Understanding and Monitoring Abrupt Climate Change and Its Impacts; Board on Atmospheric Sciences and Climate; Division on Earth and Life Studies; National Research Council
COMMITTEE ON UNDERSTANDING AND MONITORING ABRUPT CLIMATE CHANGE AND ITS IMPACTS:
- JAMES W.C. WHITE (Chair), University of Colorado, Boulder
- RICHARD B. ALLEY, Pennsylvania State University, University Park
- DAVID E. ARCHER, University of Chicago, Illinois
- ANTHONY D. BARNOSKY, University of California, Berkeley
- JONATHAN FOLEY, University of Minnesota, Saint Paul
- RONG FU, University of Texas at Austin
- MARIKA M. HOLLAND, National Center for Atmospheric Research, Boulder, Colorado
- M. SUSAN LOZIER, Duke University, Durham, North Carolina
- JOHANNA SCHMITT, University of California, Davis
- LAURENCE C. SMITH, University of California, Los Angeles
- GEORGE SUGIHARA, University of California, San Diego
- DAVID W. J. THOMPSON, Colorado State University, Fort Collins
- ANDREW J. WEAVER, University of Victoria, British Columbia
- STEVEN C. WOFSY, Harvard University, Cambridge, Massachusetts
- National Academy of Sciences Report (check out “related resources” in addition to reading the summary)
- REPORT BRIEF PDF
- Abrupt Changes Table
Climate is changing, forced out of the range of the past million years by levels of carbon dioxide and other greenhouse gases not seen in the Earth’s atmosphere for a very, very long time. Lacking action by the world’s nations, it is clear that the planet will be warmer, sea level will rise, and patterns of rainfall will change. But the future is also partly uncertain — there is considerable uncertainty about how we will arrive at that different climate. Will the changes be gradual, allowing natural systems and societal infrastructure to adjust in a timely fashion? Or will some of the changes be more abrupt, crossing some threshold or “tipping point” to change so fast that the time between when a problem is recognized and when action is required shrinks to the point where orderly adaptation is not possible?
Abrupt Impacts of Climate Change is an updated look at the issue of abrupt climate change and its potential impacts. This study differs from previous treatments of abrupt changes by focusing on abrupt climate changes and also abrupt climate impacts that have the potential to severely affect the physical climate system, natural systems, or human systems, often affecting multiple interconnected areas of concern. The primary timescale of concern is years to decades. A key characteristic of these changes is that they can come faster than expected, planned, or budgeted for, forcing more reactive, rather than proactive, modes of behavior.
Abrupt Impacts of Climate Change summarizes the state of our knowledge about potential abrupt changes and abrupt climate impacts and categorizes changes that are already occurring, have a high probability of occurrence, or are unlikely to occur. Because of the substantial risks to society and nature posed by abrupt changes, this report recommends the development of an Abrupt Change Early Warning System that would allow for the prediction and possible mitigation of such changes before their societal impacts are severe. Identifying key vulnerabilities can help guide efforts to increase resiliency and avoid large damages from abrupt change in the climate system, or in abrupt impacts of gradual changes in the climate system, and facilitate more informed decisions on the proper balance between mitigation and adaptation. Although there is still much to learn about abrupt climate change and abrupt climate impacts, to willfully ignore the threat of abrupt change could lead to more costs, loss of life, suffering, and environmental degradation. Abrupt Impacts of Climate Change makes the case that the time is here to be serious about the threat of tipping points so as to better anticipate and prepare ourselves for the inevitable surprises.
Tipping points: Where may abrupt impacts from climate change occur?
(December 3, 2013) ScienceDaily — Climate change has increased concern over possible large and rapid changes in the physical climate system, which includes Earth’s atmosphere, land surfaces, and oceans. Some of these changes could occur within a few decades or even years, leaving little time for society and ecosystems to adapt. A new report from the National Research Council extends this idea of abrupt climate change, stating that even steady, gradual change in the physical climate system can have abrupt impacts elsewhere — in human infrastructure and ecosystems for example — if critical thresholds are crossed.
The report calls for the development of an early warning system that could help society better anticipate sudden changes and emerging impacts. …
Further scientific research and enhanced monitoring of the climate, ecosystems, and social systems may be able to provide information that a tipping point is imminent, allowing time for adaptation or possibly mitigation, or that a tipping point has recently occurred, the report says. “Right now we don’t know what many of these thresholds are,” White said. “But with better information, we will be able to anticipate some major changes before they occur and help reduce the potential consequences.” The report identifies several research needs, such as identifying keystone species whose population decline due to an abrupt change would have cascading effects on ecosystems and ultimately on human provisions such as food supply.
If society hopes to anticipate tipping points in natural and human systems, an early warning system for abrupt changes needs to be developed, the report says. An effective system would need to include careful and vigilant monitoring, taking advantage of existing land and satellite systems and modifying them if necessary, or designing and implementing new systems when feasible. It would also need to be flexible and adaptive, regularly conducting and alternating between data collection, model testing and improvement, and model predictions that suggest future data needs.
NPR December 03, 2013 5:01 PM
An expert panel at the National Academy of Sciences is to alert us to abrupt and potentially catastrophic events triggered by climate change. The committee says science can anticipate some major changes to the Earth that could affect everything from agriculture to sea level. But we aren’t doing enough to look for those changes and anticipate their impacts. And this is not a matter for some distant future. The Earth is already experiencing both gradual and abrupt climate change. The air is warming up slowly, and we’re also seeing rapid changes such as the melting Arctic ice cap.
….”When you think about gradual changes you can kind of see where the road is and know where you’re going,” Barnosky said at a news conference unveiling the report Tuesday. “When you think about abrupt changes and threshold effects, the road suddenly drops out from under you. And it’s those kinds of things we’re suggesting we need to anticipate in a much more comprehensive way.”
Scientists know about some potential problems that could change the planet dramatically in a matter of years or decades. For example, sea level could quickly rise by as much as 25 feet if the West Antarctic Ice Sheet were to crumble into the sea. Yet committee chairman James White, an earth scientist at the University of Colorado in Boulder, says we’re not watching that ice sheet very carefully to measure how much warming seawater is weakening the ice. “We should be measuring ocean temperatures near the ice sheet,” White said. “We should be measuring, far better, where the outlets are — where the glaciers go into the ocean. We don’t do that.”
Another potential for disaster is in the Arctic. There is a huge amount of methane gas up there. The report says the region is unlikely to belch methane into the atmosphere rapidly and supercharge global warming. But government agencies aren’t keeping a close eye on methane and other greenhouse gases in the Arctic…. We know there needs to be monitoring capability,” White said. “We know we need to be watching the planet. We watch our streets, we watch our banks — if you live in the U.K. they watch everything — we watch other parts of the system very well. “But we do not watch our environment with nearly the same amount of care and zeal.” The committee didn’t just consider abrupt changes to the planet. It also looked at gradual changes that could trigger rapid disruptions for us. For example, parts of the Earth could quickly become inhospitable to crops like corn, once the temperature creeps past a certain threshold. Those concerns are greatest in the tropics and subtropics. “Probably the biggest issues are going to show up in the warm places, even though it will be easier to see them, and we will meet them sooner, in the Arctic,” says , a glaciologist at Penn State…..
WASHINGTON December 3, 2013 (AP) By SETH BORENSTEIN AP Science Writer
Hard-to-predict sudden changes to Earth’s environment are more worrisome than climate change’s bigger but more gradual impacts, a panel of scientists advising the federal government concluded Tuesday. The 200-page report by the National Academy of Sciences looked at warming problems that can occur in years instead of centuries. The report repeatedly warns of potential “tipping points” where the climate passes thresholds, beyond which “major and rapid changes occur.” And some of these quick changes are happening now, said study chairman James White of the University of Colorado.
The report says abrupt changes like melting ice in the Arctic Ocean and mass species extinctions have already started and are worse than predicted. It says thousands of species are changing their ranges, seasonal patterns or in some cases are going extinct because of human-caused climate change. Species in danger include some coral; pika, a rabbitlike creature; the Hawaiian silversword plant and polar bears. At the bottom of the world in Antarctica, the melting ice in the west could be more of a wild card than originally thought. If the massive ice sheet melts it may happen relatively rapidly and could raise world sea levels by 13 feet, but researchers aren’t certain how soon that may occur. However, the report had what researchers called “good news.” It said two other abrupt climate threats that worried researchers likely won’t be so sudden, giving people more time to prepare and adapt. Those two less-imminent threats are giant burps of undersea and frozen methane, a super-potent greenhouse gas, and the slowing of deep ocean currents. That slowdown is a scenario that would oddly lead to dramatic coastal cooling and was featured in the 2004 movie “The Day After Tomorrow.” Study co-author Richard Alley of Pennsylvania State University compared the threat of abrupt climate change effects to the random danger of drunk drivers. “You can’t see it coming, so you can’t prepare for it. The faster it is, the less you see it coming, the more it costs,” Alley told The Associated Press. “If you see the drunk driver coming, you can get out of the way.” The scientists said the issue of sudden changes is full of uncertainties, so the world can better prepare by monitoring places like Antarctic and Greenland ice sheets more. But because of budget cuts and aging satellites, researchers have fewer measurements of these crucial indicators than they did a few years ago and will have even fewer in upcoming years, study co-author Steven Wofsy of Harvard University said. The panel called on the government to create an early warning system….
By JUSTIN GILLIS NY Times December 3 2013
A scientific panel’s report ruled out some doomsday notions but said that dire climatic surprises seemed inevitable.
New York Times (blog)
Dec 3, 2013
The findings laid out below reinforce the reality that the biggest impacts of greenhouse-driven global warming still lie several generations in the future.