Posts tagged climate change
Climate change: Big changes for big mammals
Jan 23rd
in mammal responses to climate change
If you were a shrew snuffling around a North American forest, you would be 27 times less likely to respond to climate change than if you were a moose grazing nearby.
That is just one of the findings of a new University of Colorado Boulder assessment led by Assistant Professor Christy McCain that looked at more than 1,000 different scientific studies on North American mammal responses to human-caused climate change. The CU-Boulder team eventually selected 140 scientific papers containing population responses from 73 North American mammal species for their analysis.
The studies assessed by the team examined seven different responses to climate change by individual mammal species: local extinctions of species known as extirpations, range contractions, range shifts, changes in abundance, seasonal responses, body size and genetic diversity. The researchers used statistical models to uncover whether the responses of the 73 mammals to a changing climate were related to aspects of their physiology and behavior or the location of the study population.
The analysis showed only 52 percent of the mammal species responded as expected to climate change, while 7 percent responded the opposite of expectations and the remaining 41 percent had no detectable response. The two main traits tied to climate change responses in the CU-Boulder study were large mammal body size and restricted times during a 24-hour day when particular mammal species are active, she said.
A paper on the study by McCain and former CU-Boulder postdoctoral fellow Sarah King was published online Jan. 22 in the journal Global Change Biology. The National Science Foundation funded the study. King is currently a research associate at Colorado State University.
While body size was by far the best predictor for response to climate change — almost all of the largest mammals responded negatively — the new study also showed that mammals active only during the day or only at night were twice as likely to respond to climate change as mammals that had flexible activity times, she said.
“This is the first time anyone has identified specific traits that tell us which mammals are responding to climate change and which are not,” said McCain of CU-Boulder’s ecology and evolutionary biology department.
McCain said she and King were surprised by some of the findings. “Overall the study suggests our large, charismatic fauna — animals like foxes, elk, reindeer and bighorn sheep — may be at more risk from climate change,” she said. “The thinking that all animals will respond similarly and uniformly to temperature change is clearly not the case.”
The researchers also found that species with higher latitudinal and elevation ranges, like polar bears, American pikas and shadow chipmunks, were more likely to respond to climate change than mammals living lower in latitude and elevation. The ability of mammals to hibernate, burrow and nest was not a good predictor of whether a species responded to climate change or not. American pikas have been extirpated from some of their previously occupied sites in the West, as have shadow chipmunks, which are in decline in California’s Yosemite National Park.
One of the most intriguing study findings was that some small mammals may shelter from climate change by using a wider array of “micro-climates” available in the vegetation and soil, she said. McCain compared the findings with the events at the K-T boundary 66 million years ago when an asteroid smacked Earth, drastically changing the climate and killing off the big dinosaurs but sparing many of the small mammals that found suitable shelter underground to protect them from the cataclysmic event.
“I think the most fascinating thing about our study is that there may be certain traits like body size and activity behaviors that allow some smaller mammals to expand the range of temperature and humidity available to them,” said McCain, also a curator of vertebrate zoology at the University of Colorado Museum of Natural History. “These areas and conditions are not available to bigger mammals that live above the vegetation and experience only ambient temperatures.”
The new study builds on a growing body of global information documenting the shifting behaviors and environments of organisms like flowers, butterflies and birds in response to a warming world, said McCain.
“If we can determine which mammals are responding to climate change and the ones that are at risk of disappearing, then we can tailor conservation efforts more toward those individual species,” said McCain. “Hopefully, this potential loss or decline of our national iconic mammals will spur more people to curb climate impacts by reducing overuse of fossil fuels.”
For more information on the ecology and evolutionary biology department visit http://ebio.colorado.edu. For more information on the University of Colorado Museum of Natural History visit http://cumuseum-archive.colorado.edu/About/directory.html.
Climate change early warning system called for
Dec 3rd
Climate change has increased concern over possible large and rapid changes in the physical climate system, including Earth’s atmosphere, land surfaces and oceans, said Professor James White of CU-Boulder’s Institute of Arctic and Alpine Research and the chair of the National Research Council committee. Some abrupt changes and impacts already underway – including the loss of Arctic sea ice and increases in the extinction rates of marine and terrestrial species – and others could occur within a few decades or even years, said the committee.
“Research has helped us begin to distinguish more imminent threats from those that are less likely to happen this century,” said White, also a CU-Boulder professor in geological sciences. “Evaluating climate changes and impacts in terms of their potential magnitude and the likelihood they will occur will help policymakers and communities make informed decisions about how to prepare for or adapt to them.”
Other scenarios, such as the destabilization of the west Antarctic ice sheet, have potentially major consequences, but the probability of these changes occurring within the next century is not well understood, highlighting the need for more research, according to the committee.
In some cases, scientific understanding has progressed enough to determine whether certain high-impact climate changes are likely to happen within the next century. The report notes that a shutdown in the Atlantic Ocean circulation patterns or a rapid release of methane from high-latitude permafrost or undersea ice are now known to be unlikely this century, although these potential abrupt changes are still worrisome over longer time horizons.
But even changes in the physical climate system that happen gradually over many decades or centuries can cause abrupt ecological or socio-economic change once a “tipping point” is reached, the report adds. Relatively slow global sea-level rise could directly affect local infrastructure such as roads, airports, pipelines or subway systems if a sea wall or levee is breached. And slight increases in ocean acidity or surface temperatures could cross thresholds beyond which many species cannot survive, leading to rapid and irreversible changes in ecosystems that contribute to extinction events.
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 model predictions that suggest future data needs.
The study was sponsored by the National Oceanic and Atmospheric Administration, National Science Foundation, U.S. intelligence community, and the National Academies. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, independent nonprofit institutions that provide science, technology, and health policy advice under a congressional charter granted to NAS in 1863. The National Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering.
For more information and a copy of the report visit http://national-academies.org. For more information on INSTAAR visithttp://instaar.colorado.edu.
ESA: So much accomplished, so much to do
Nov 13th
BC1 news editor
The federal Endangered Species turns 40 years old this year. It was signed into law by Richard (“I am not a crook”) Nixon, in 1973, likely as a desperation move to garner public support for his collapsing presidency. The significance of this law is that, for the first time in history federal law recognized there are limits to economic development —i.e. when a species would be driven to extinction as a result of the activities. That, my friends, is a Line in the Sand.
The ESA has been incredibly effective, thanks almost entirely to the Center for Biological Diversity, which was instrumental in protecting more than 1,400 species and 200 million acres of critical habitat in the U.S. alone. Ninety nine percent of species protected by the ESA have been saved from extinction. The CBD uses law and science to make its case, bucking the trend of most major environmental groups, which rarely sue any longer for any reason. This happened because BIG OIL has undue influence in the environmental community by having representatives on the environmental groups’ board of directors and by funding these groups with the tacit understanding that the groups won’t oppose projects beneficial to oil and gas profits. Nevertheless, current trends are threatening to reverse the situation. Global climate change could be the most damaging threat in history, with profound implications for both animals and human beings. There are others.
To honor the ESA, Boulder Channel 1 will run a series of articles about the most serious of these threats.
By the Center for Biological Diversity
FRACKING THREATENS AMERICA’S AIR, WATER AND CLIMATE It poisons our water, contaminates our air and emits massive greenhouse gas pollution. Hydraulic fracturing, or fracking, involves blasting huge volumes of water mixed with toxic chemicals and sand deep into the earth to fracture rock formations and release oil and natural gas. This extreme form of energy production endangers our health and wildlands.
A fracking boom can transform an area almost overnight, creating massive new environmental and social problems. Fracking development is intensifying in Pennsylvania, Texas and North Dakota and moving into new areas, like California and Nevada. Will your state be fracked next? But as fracking spreads across America, communities are fighting back — and the Center for Biological Diversity is working to ban this growing threat. POLLUTING AIR AND WATER, KILLING WILDLIFE
About 25 percent of fracking chemicals could cause cancer, scientists say. Others harm the skin or reproductive system. Evidence is mounting throughout the country that these chemicals — as well as methane released by fracking — are making their way into aquifers and drinking water. Fracking can release dangerous petroleum hydrocarbons, including benzene and xylene. It also increases ground-level ozone levels, raising people’s risk of asthma and other respiratory illnesses. Wildlife is also in danger. Fish die when fracking fluid contaminates streams and rivers. Birds are poisoned by chemicals in wastewater ponds. And the intense industrial development accompanying fracking pushes imperiled animals out of wild areas they need to survive. In California, for example, more than 100 endangered and threatened species live in the counties where fracking is set to expand. DISRUPTING
OUR CLIMATE Fracking releases large amounts of methane, a dangerously potent greenhouse gas. Fracked shale gas wells, for example, may have methane leakage rates as high as 7.9 percent, which would make such natural gas worse for the climate than coal. But fracking also threatens our climate in another way. To prevent catastrophic climate change, we must leave about 80 percent of proven fossil fuel reserves in the ground. Fracking takes us in the opposite direction, opening up vast new deposits of fossil fuels. If the fracking boom continues, oil and gas companies will light the fuse on a carbon bomb that will shatter efforts to avert climate chaos. BAN FRACKING NOW To protect our environment from fracking, we must prohibit this inherently dangerous technique. That’s why the Center supports fracking bans and moratoriums at the local, state and national levels. Learn about fracking and please take action against it today.