Category Archives: Environmental

The Climate Change Facts You Need to Know

This week, world leaders are converging in Paris to talk about climate policy. Under current guidelines, the planet is on target to warm by 2 degrees Celsius in 2050 and by 4 degrees in 2100, triggering serious large-scale problems by the end of the century.

“Drought, heat waves, forest fires — we are already seeing this,” says V. Ramanathan, an atmospheric scientist.

Ramanathan, who will be speaking at the conference, accurately predicted this trend back in 1980. In the video above, he explains how we might be able to change our course on climate.

Small volcanic eruptions explain warming hiatus

Scientists have long known that volcanoes cool the atmosphere because of the sulfur dioxide that is expelled during eruptions. Droplets of sulfuric acid that form when the gas combines with oxygen in the upper atmosphere can persist for many months, reflecting sunlight away from Earth and lowering temperatures at the surface and in the lower atmosphere.

Previous research suggested that early 21st-century eruptions might explain up to a third of the recent warming hiatus.

New research available online in the journal Geophysical Research Letters (GRL) further identifies observational climate signals caused by recent volcanic activity. This new research complements an earlier GRL paper published in November, which relied on a combination of ground, air and satellite measurements, indicating that a series of small 21st-century volcanic eruptions deflected substantially more solar radiation than previously estimated.

“This new work shows that the climate signals of late 20th- and early 21st-century volcanic activity can be detected in a variety of different observational data sets,” said Benjamin Santer, a Lawrence Livermore National Laboratory scientist and lead author of the study.

The warmest year on record is 1998. After that, the steep climb in global surface temperatures observed over the 20th century appeared to level off. This “hiatus” received considerable attention, despite the fact that the full observational surface temperature record shows many instances of slowing and acceleration in warming rates. Scientists had previously suggested that factors such as weak solar activity and increased heat uptake by the oceans could be responsible for the recent lull in temperature increases. After publication of a 2011 paper in the journal Science by Susan Solomon of the Massachusetts Institute of Technology, it was recognized that an uptick in volcanic activity might also be implicated in the warming hiatus.

Prior to the 2011 Science paper, the prevailing scientific thinking was that only very large eruptions — on the scale of the cataclysmic 1991 Mount Pinatubo eruption in the Philippines, which ejected an estimated 20 million metric tons (44 billion pounds) of sulfur — were capable of impacting global climate. This conventional wisdom was largely based on climate model simulations. But according to David Ridley, an atmospheric scientist at MIT and lead author of the November GRL paper, these simulations were missing an important component of volcanic activity.

Ridley and colleagues found the missing piece of the puzzle at the intersection of two atmospheric layers, the stratosphere and the troposphere — the lowest layer of the atmosphere, where all weather takes place. Those layers meet between 10 and 15 kilometers (6 to 9 miles) above the Earth.

Satellite measurements of the sulfuric acid droplets and aerosols produced by erupting volcanoes are generally restricted to above 15 km. Below 15 km, cirrus clouds can interfere with satellite aerosol measurements. This means that toward the poles, where the lower stratosphere can reach down to 10 km, the satellite measurements miss a significant chunk of the total volcanic aerosol loading.

To get around this problem, the study by Ridley and colleagues combined observations from ground-, air- and space-based instruments to better observe aerosols in the lower portion of the stratosphere. They used these improved estimates of total volcanic aerosols in a simple climate model, and estimated that volcanoes may have caused cooling of 0.05 degrees to 0.12 degrees Celsius since 2000.

The second Livermore-led study shows that the signals of these late 20th and early 21st eruptions can be positively identified in atmospheric temperature, moisture and the reflected solar radiation at the top of the atmosphere. A vital step in detecting these volcanic signals is the removal of the “climate noise” caused by El Niños and La Niñas.

“The fact that these volcanic signatures are apparent in multiple independently measured climate variables really supports the idea that they are influencing climate in spite of their moderate size,” said Mark Zelinka, another Livermore author. “If we wish to accurately simulate recent climate change in models, we cannot neglect the ability of these smaller eruptions to reflect sunlight away from Earth.”

To see the full research, go to Geophysical Research Letters and the Wiley Online Library.

The Livermore-led research involved a large interdisciplinary team of researchers with expertise in climate modeling, satellite data, stratospheric dynamics, volcanic effects on climate, model evaluation, statistics and computer science. Other Livermore contributors include Céline Bonfils, Jeff Painter, Francisco Beltran and Gardar Johannesson. Other collaborators include Solomon and Ridley of MIT, John Fyfe at the Canadian Centre for Climate Modeling and Analysis, Carl Mears and Frank Wentz at Remote Sensing Systems and Jean-Paul Vernier at the NASA/Goddard Space Flight Center.

Warming Seas Drive Rapid Acceleration of Melting Antarctic Ice

As warm ocean water rises up to melt them, glaciers around the Amundsen Sea are losing half a Mount Everest a year.

A second study, published Thursday in the journal Science, helps explain the accelerating ice melt: Warm ocean water is melting the floating ice shelves that hold back the glaciers.

The two new pieces of research come as officials of the World Meteorological Organization announced Wednesday that 2014 is on track to be the warmest year on record.

Scientists have long worried that the West Antarctic ice sheet is a place where climate change might tip toward catastrophe. The ice sheet holds enough water to raise sea level by 16 feet (5 meters). The region along the Amundsen Sea is the sheet’s soft underbelly, where the ice is most vulnerable. (See “Rising Seas” in National Geographic magazine.)

Earlier this year, researchers at the University of California, Irvine and NASA’s Jet Propulsion Laboratory reported that the glaciers flowing into the Amundsen Sea—notably the Pine Island and Thwaites Glaciers—were already doomed to collapse, and at the current rate of melting would be gone in 200 years.

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Green But Not Green: Pot & The Environment

New research suggests that unlawful marijuana farming is diverting water sources, poisoning animals, and increasing erosion.

It began with dying weasels. First one, then many, all mysteriously killed by rat poison banned in the lush Northern California forests where the animals live. Damning evidence soon pointed to a surprising culprit: illegal marijuana farms, where growers use poisons to protect an increasingly lucrative crop.

But the damage caused by pot farms is greater than just one species of poisoned animal—it is far reaching, harming forests, streams, and broad wildlife populations. As states like California debate the legality of marijuana, new research suggests the discussion should focus not only on citizens’ right to smoke, but the broader impact of producing the drug.

There is a surprisingly strong environmental case to be made in favor of legalizing pot, because illegal marijuana is so bad for California’s wilderness and wildlife.

“It’s not just a moral and ethical debate,” says Mourad W. Gabriel, a scientist at the University of California, Davis, who helped unravel the mystery of the dying weasels. “It’s a major environmental concern.”

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Could cherry blossoms one day be blooming in winter?

Chery Blossoms

The cherry blossoms in Washington D.C.’s annual festival now bloom five days earlier than when the festival was celebrated in 1921 (on average). Scientists theorize that with the drastic warming of the globe, future decades could see blossom times not just a few days early but advanced by almost a month.

To better understand the situation, researchers need large amounts of data about different all types of plants in order to analyze. Gathering all of this data is not easy.

UC Santa Barbara’s Susan Mazer explains why researchers need the public’s help to gather this information:

Facebook for Nature

Can a status update from a tulip tell us anything about climate change?

The science of seasonal observation has always mattered, but never has it been so urgent. Each year, our seasons unfold. Perhaps they feel the same to us each time, or maybe we notice the slight differences. A lack of rain in the west, and a barrage of snow in the east. Flowers are blooming earlier, fruit is ripening sooner. OK, so what’s the big deal with some slightly confused flora? Well, that confusion ripples outward, and that matters because of how beholden all living things are to other living things. The timing of our ecosystem, complicated as it is in the most ideal of times, is off-kilter.

The California Phenology Project, a collaboration between UC Santa Barbara, the National Park Service, and The National Phenology Network endeavors to document plant ranges, flowering dates, and other relevant data to assess climate change responses throughout the state of California. In the UC Natural Reserve System there are 3,300 plant species. The list reads like a poem of plants you may have never heard of: Awned Fescue, Ripgut Grass, Winecup Clarkia. The idea is that when these plants bloom within the season (and how that differs year to year) is actually a clue, indicative of the world they are blossoming into.

The phenological observations of scientists and citizens alike will all contribute to the Pheonology Project’s online resource, Nature’s Notebook, a kind of Facebook for Nature (I would totally friend request the California Poppy, golden and archetypal as it is, and Winecup Clarkia too, in all its hot pink, magenta splendor). But unlike the existential quandaries posed by the ubiquitous social media site, this online notebook will begin to reveal some of the patterns of our natural world and what that might mean for us. Since the task at hand is too large for just the professional scientists, now is the chance for people to reconnect with their environment and become contributors to this project, citizen-scientists observing and noting the plant species in Golden Gate Park or in their own backyard. We are all capable of phenological observation. The California Poppy accepts your friendship request! What will you do now?

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The Frog of War

When biologist Tyrone Hayes discovered that a top-selling herbicide messes with sex hormones, its manufacturer went into battle mode:

In 2001, seven years after joining the biology faculty of the University of California, Berkeley, Tyrone Hayes stopped talking about his research with people he didn’t trust. He instructed the students in his lab, where he was raising three thousand frogs, to hang up the phone if they heard a click, a signal that a third party might be on the line. Other scientists seemed to remember events differently, he noticed, so he started carrying an audio recorder to meetings. “The secret to a happy, successful life of paranoia,” he liked to say, “is to keep careful track of your persecutors.”

Three years earlier, Syngenta, one of the largest agribusinesses in the world, had asked Hayes to conduct experiments on the herbicide atrazine, which is applied to more than half the corn in the United States. Hayes was thirty-one, and he had already published twenty papers on the endocrinology of amphibians. David Wake, a professor in Hayes’s department, said that Hayes “may have had the greatest potential of anyone in the field.” But, when Hayes discovered that atrazine might impede the sexual development of frogs, his dealings with Syngenta became strained, and, in November, 2000, he ended his relationship with the company.

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