What’s the News: Climate change may have sparked the demise of early Viking settlements in Greenland, according to a new study published online in the Proceedings of the National Academy of Sciences, when temperatures cooled rapidly over several decades. Around the time the Vikings disappear from the island’s archaeological record, temperature appears to have plunged. Nor were the Vikings the only people in Greenland whose fortunes rose and fell with the average temperature, the study suggests. Earlier cold spells may have played a role in the collapse of two previous groups on the island.
What’s the News: Geologists have known for years that tectonic plates affect climate patterns. Now they say that the opposite is also true, finding that intensifying climate events can move tectonic plates. Using models based on known monsoonal and plate movement patterns, geologists say that the Indian Plate has accelerated by about 20% over the past 10 million years. “The significance of this finding lies in recognising for the first time that long-term climate changes have the potential to act as a force and influence the motion of tectonic plates,” Australian National University researcher Giampiero Iaffaldano told COSMOS.
Climatologists have long used tree rings and ancient ice to track global warming trends—and while they’re currently the methods of choice for most researchers, other scientists have found some clever (and boarderline bizarre) ways of studying our changing climate. Some clever scientists are finding hidden climate clues in places you wouldn’t expect, from old newspapers to impressionist paintings.
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Starting this week, NASA will have a new eye in the sky to better sort out the way that greenhouse gases, air pollution, and solar activity interact to affect the climate of our planet. The Glory satellite, currently set to launch on Friday, will spy on changes both in our atmosphere and in the sun.
Its main job will be to study fine airborne particles known as aerosols. Smaller than the diameter of a human hair, these specks can move great distances across the globe and are largely responsible for hazy skies. [The New York Times]
Greenhouse gases and their contribution to climate change have been the subject of much research, of course, but aerosols remain murkier. Climate scientist James Hansen, a member of the Glory team, says researchers must use an uncertainty range for modeling aerosols that’s three to four times greater than what they use with greenhouse gases, simply because the contribution of aerosols is much less understood.
The Glory mission will, if all goes according to plan, collect data on the micro-physical, chemical and optical properties of aerosols using two instruments—an Aerosol Polarimetry Sensor (ARS) and a Total Irradiance Monitor (TIM)—that will monitor the climate system and provide new data for scientists working on the issue of climate change. The APS will collect visible and near-infrared data scattered from aerosols and clouds and the TIM, mounted on a special track that allows it move independent of the satellite, should record total electromagnetic radiation given off by the sun that hits the top of Earth’s atmosphere. [The Atlantic]
One cannot look at a single storm, flood, or drought and say conclusively, “climate change caused that.” But what researchers are attempting to do lately is climate change risk assessment—figuring out how much more likely severe events may become as our world continues to warm up. Two new studies in Nature today try to do just that with heavy rains and flooding, saying definitively that warm temperatures make these events more likely.
More-localized weather extremes have been harder to attribute to climate change until now. “Climate models have improved a lot since ten years ago, when we basically couldn’t say anything about rainfall,” says Gabriele Hegerl, a climate researcher at the University of Edinburgh, UK. [Nature]
Hegerl and climate researcher Francis Zwiers were authors on study number one, a broad-based look at how much humans are contributing to intense precipitation events in the Northern Hemisphere. The simple physics of it makes sense: warmer air can hold more water. To show a link, however, the researchers pulled together a half-century of rainfall records, which they compared to the results of eight different climate models.
Richard Allan, a climate scientist at the University of Reading in England who was not part of the study, called the method employed by Zwiers “very rigorous.” He added, “There’s already been quite a bit of evidence showing that there has been an intensification of rainfall” events across the globe. But until now “there had not been a study that formally identified this human effect on precipitation extremes,” Zwiers said. “This paper provides specific scientific evidence that this is indeed the case.” [Washington Post]
The drastic changes in the Arctic wrought by global warming aren’t just threatening that icon of climate change the polar bear, they’re also jeopardizing the health of other species–like the Pacific walrus. Environmentalists petitioned the federal government years ago to add the walrus to the endangered species list, but progress on the case has been slow. Now, in a decision that has angered both activists and oil drillers, the U.S. Fish and Wildlife Service has decided that even though our be-blubbered friends deserve recognition under the Endangered Species Act, there are just too many other endangered animals to take care of first.
Specifically, the organization’s spokesman, Bruce Woods, said that protecting walruses was advised but “precluded.” That’s because other animals, like polar bears and certain species of sea birds, are more imperiled in this world of receding ice. The agency also said it’s hampered by lack of firm data on walrus population numbers.
“The main thing is that, compared to the polar bears, there are a lot of them,” Woods said of the Pacific walrus, adding that no baseline population count for the walrus exists…. “We don’t have any evidence of declines,” even if declines are suspected, he said. [Reuters]
The Agency’s decision has raised the ire of many.
The Earth’s climate swings have disrupted human societies and civilizations throughout our species’ history; take examples like those in Jared Diamond’s Collapse. But are they also connected to one of the most famous collapses in the history books—the fall of the Roman Empire?
There are a host of reasons for the fall of Rome, researchers led by paleoclimatologist Ulf Büntgen write today in the journal Science. However, analyzing the climate records of the past 2,500 years reveals that changes to Europe’s climate coincided with the rise and fall of the famous civilization. Such a correlation could suggest that climate played some part in building the Romans up and in tearing them down.
Büntgen and colleagues collaborated with archaeologists to amass a database of more than 9,000 pieces of wood dating back 2,500 years. Samples came from both live trees and remains of buildings and other wooden artifacts, all from France and Germany. By measuring the width of annual growth rings in the wood, the researchers were able to determine temperature and precipitation levels on a year-by-year basis. [Discovery News]
The results of this unprecedented collection of climate data: In the third century B.C., when Rome fought the First and Second Punic wars against Carthage and began its ascent to Mediterranean empire, times were good. The rains fell, the temperatures were warm, and agriculture would have flourished. But by the third century A.D., the time when the Germanic invasions began to creep further into Roman territory, more droughts had come to Western Europe. This trend persisted into about the 6th century A.D.
For several years now, the Environmental Protection Agency has been lurching toward enacting rules to regulate greenhouse gases under the Clean Air Act. Yesterday, the first steps of the EPA’s new rules went into effect.
The new regulations come in two parts, the first of which limits the emissions allowed by new cars and light trucks.
The rules apply to 2012 model vehicles, which can be sold starting Sunday. They must now follow toughened CAFE fuel efficiency standards laid out in May. With industry on board—though there’s some grumbling—these steps are relatively uncontroversial. [ScienceNOW]
The second and more contentious part of EPA’s action are new rules for power plants, factories, and refineries. Beginning yesterday (January 2), any new plant that will emit more than 100,000 tons of carbon dioxide (or the equivalent) annually will need an EPA permit, as will existing plants that install new capacity that emits 75,000 tons or more. The regulations for all existing plants will follow this July, when those that emit the equivalent of 100,000 annual tons will need permits to do so.
It’s beginning to look a lot like… self-inflicted doom.
This week Associated Press reporters tallied the toll of the year in natural disasters, and it added up to some depressing results. Around the world—in Haiti and Chile earthquakes, in Pakistani floods, in Russian heat waves—nature unleashed its fury in extreme fashion in 2010, the AP says, and humans made it worse through our own actions.
“It just seemed like it was back-to-back and it came in waves,” said Craig Fugate, who heads the U.S. Federal Emergency Management Agency. It handled a record number of disasters in 2010. “The term ‘100-year event’ really lost its meaning this year.” [AP]
At least 250,000 people died in natural disasters this year, up from just 15,000 last year. But, the AP’s Seth Bornstein argues, this isn’t just natural variability.
For one thing, there are the avoidable problems of not doing enough to prepare for the inevitable appearance of disaster. The 2010 death toll is skewed so high this year because of the Haiti earthquake in January that killed most of the people in that quarter-million group. There’s nothing to be done about the shifts of tectonic plates, but the death toll skyrocketed because so many poor Haitians were living in such poorly built dwellings. The more powerful Chilean earthquake, by contrast, occurred in a place with better-built structures and killed fewer than a thousand. While in Pakistan, having so many homes in the flood zone exacerbated the damage when the monsoons came in July.