Global warming mystery: Why are some glaciers growing? - Around the world, ice caps are melting due to climate change. But a few icy masses in the Himalayas are, weirdly enough, getting bigger
Glaciers around the world are slowly melting, and scientists are quick to point their fingers at manmade climate change. But new research suggests that a few glaciers aren't shrinking at all, and may even be growing. Here, a brief guide to this counterintuitive phenomenon:
Which glaciers are growing?
A few glaciers in the Karakoram mountain range along the India-China-Pakistan border are gaining mass, according to a report published in the April issue of the journal Nature Geoscience. "The rest of the glaciers in the Himalayas are mostly melting," lead researcher Julie Gardelle tells LiveScience. "This is an anomalous behavior."
How are scientists so sure?
Researchers used satellite imaging to "analyze the extent of the ice in about a quarter of the range — about 2,167 square miles," says Jennifer Welsh at LiveScience. Photos taken in 2008 were compared to images taken in 1999, and scientists discovered that glaciers grew an estimated 0.36 to 0.72 feet each year.
What makes a glacier change in size?
Snow fall and temperature are the primary factors. And as the world gets warmer, most glaciers are shrinking and melting, causing sea levels to rise about 0.04 millimeters per year on average. Scientists estimate that the melting of glaciers, ice caps, and ice sheets around the world has caused more than 1,000 cubic miles of ice to disappear from 2003 to 2010.
So why are these Himalayan glaciers getting bigger?
No one's certain, but scientists have a few ideas. Stephan Harrison of the U.K.'s University of Exeter thinks it may have something to do with avalanches from surrounding mountains, which can pack on ice. Others think it could be that the climate in the Karakoram mountains is cooling, even as the rest of the world warms. "Records from weather stations between 1961 and 2000 showed that there had been an increase in winter precipitation and a decrease in average temperatures during the summer," says PlanetSave. ( The Week )
Global Warming Makes Elephant Seals Dive Deeper, Study Suggests - Lumbering elephant seals in Antarctica seem to be taking the heat from global warming, as scientists have found the mammals must dive to deeper than normal depths in warmer seas to snag food. The deeper dives may also mean less time to get food, the researchers say.
The southern elephant seals from Marion Island in the Southern Ocean surrounding Antarctica are some of the most extreme divers, spending 65 percent of their time deeper than about 330 feet (100 meters), with a maximum diving depth of 6,560 feet (2,000 meters). Southern elephant seals are also the largest of the seals, with males reaching up to 22 feet (6.7 m) long and weighing some 11,000 pounds.
Their dive depth, it seems, depends on the prey the elephant seals are searching for. And as their watery world warms, the researchers found, the squid and fish that are usually in waters above 3,280 feet (1,000 m) are forced to deeper waters.
The elephant seals, to get their meals, must follow.
"This prey is moving down to greater depths presumably due to the increasing water temperatures and this is forcing the seals to follow them," researcher Horst Bornemann from the Alfred Wegener Institute for Polar and Marine Research said in a statement.
Bornemann and his colleagues, including seal researchers from the Mammal Research Institute in South Africa, attached fist-size satellite transmitters to the heads of more than 30 elephant seals. The transmitters measured dive depth, water temperature and salt levels in the water every time the seals took a dive. When an elephant seal resurfaced for air, that information was sent via satellite to research institutions involved.
The data showed the elephant seals made deeper dives in warmer water so that they ultimately had less time to actually search for food, the researchers said.
"There appears to be substantial variation between individual seals in depths dived to at different temperatures," study researcher Trevor McIntyre of the Mammal Research Institute told LiveScience. Their models suggest that female elephant seals dive between 30 and 33 feet (9 and 10 meters) deeper for every 1.8 degree Fahrenheit (1 degree Celsius) increase in temperature. "However, a number of individual seals displayed much stronger relationships, diving more than 100 meters deeper per 1 degree Celsius increase in water temperature," McIntyre said.
The change in depth may mean the animals find less food. "We therefore assume that the animals will find less prey in warmer water masses," researcher Joachim Plötz of the Alfred Wegener Institute said in a statement.
To figure out if the elephant seals are indeed nabbing less prey, the researchers plan to return to Marian Island in April and attach jaw-movement sensors to the seals.
"So far, we can only derive from the dive profile whether an elephant seal was probably following a fish swarm," Plötz said. "With this new measuring device we [can] learn whether he has actually eaten."
The researchers don't know whether this colony of elephant seals will be able to adapt to the warming of the ocean. They see two options for the colony in the future: The seals can extend their hunting grounds to the colder water masses of the Antarctic or they must dive even deeper. However, the team notes, the Marion elephant seals are already close to reaching their physiological limits in diving depth. ( LiveScience.com )
Accumulating 'microplastic' threat to shores - Microscopic plastic debris from washing clothes is accumulating in the marine environment and could be entering the food chain, a study has warned.
Researchers traced the "microplastic" back to synthetic clothes, which released up to 1,900 tiny fibres per garment every time they were washed.
Earlier research showed plastic smaller than 1mm were being eaten by animals and getting into the food chain.
The findings appeared in the journal Environmental Science and Technology.
"Research we had done before... showed that when we looked at all the bits of plastic in the environment, about 80% was made up from smaller bits of plastic," said co-author Mark Browne, an ecologist now based at the University of California, Santa Barbara.
Concentrations of microplastic were greatest near coastal urban areas, the study showed
"This really led us to the idea of what sorts of plastic are there and where did they come from."
Dr Browne, a member of the US-based research network National Center for Ecological Analysis and Synthesis, said the tiny plastic was a concern because evidence showed that it was making its way into the food chain.
"Once the plastics had been eaten, it transferred from [the animals'] stomachs to their circulation system and actually accumulated in their cells," he told BBC News.
In order to identify how widespread the presence of microplastic was on shorelines, the team took samples from 18 beaches around the globe, including the UK, India and Singapore.
The smallest fibres could end up causing huge problems worldwide
"We found that there was no sample from around the world that did not contain pieces of microplastic."
Dr Browne added: "Most of the plastic seemed to be fibrous.
"When we looked at the different types of polymers we were finding, we were finding that polyester, acrylic and polyamides (nylon) were the major ones that we were finding."
The data also showed that the concentration of microplastic was greatest in areas near large urban centres.
In order to test the idea that sewerage discharges were the source of the plastic discharges, the team worked with a local authority in New South Wales, Australia.
"We found exactly the same proportion of plastics," Dr Browne revealed, which led the team to conclude that their suspicions had been correct.
As a result, Dr Browne his colleague Professor Richard Thompson from the University of Plymouth, UK carried out a number of experiments to see what fibres were contained in the water discharge from washing machines.
"We were quite surprised. Some polyester garments released more than 1,900 fibres per garment, per wash," Dr Browne observed.
"It may not sound like an awful lot, but if that is from a single item from a single wash, it shows how things can build up.
"It suggests to us that a large proportion of the fibres we were finding in the environment, in the strongest evidence yet, was derived from the sewerage as a consequence from washing clothes." ( bbc.co.uk )
Is it better for the environment to watch TV via satellite, cable, or the Internet? - I just moved into a new apartment, and I can’t decide how to get my television fix. Would it be better for the environment if I watched via cable, satellite, or streaming over the Internet?
It’s high time to examine America’s favorite pastime. According to the Bureau of Labor Statistics, Americans spend 2.7 hours per day watching television. That’s half of our leisure time, and it would account for nearly six weeks per year of round-the-clock television watching.
All other things held equal, size matters: Your energy use will be higher if you're watching TV on the flat-screen behemoth in your living room than it would if you were using the tiny display of your smartphone. So for the purposes of this comparison, let’s assume that no matter how the programming is delivered, you're looking at it on the same type of screen.
From the consumer end of the equation, the outcome is very clear: Your set-top box, whether it's hooked up to the cable system or a satellite provider, is a major waste of energy. You should get rid of it right now and switch to an Internet-based system that uses either a low-energy box or no box at all.
What's the greenest way to watch television?
Over the course of a year, a set-top high-definition cable box paired with a DVR consumes 446 kilowatt-hours, which is 31 kilowatt-hours more than an Energy Star refrigerator, according to data (PDF) compiled by the Natural Resources Defense Council and Ecos Consulting. Almost two-thirds of that consumption occurs when you’re not even watching television, because the boxes use almost as much energy when not in use.
As for the differences between set-top boxes, the cable devices consume approximately 34 watts during use, which is slightly better than the satellite models. Hardware dedicated for streaming Internet content, such as the Apple TV or Roku box, tend to perform far better, using less than 7 watts during use. The Apple model consumes just 0.5 watts in sleep mode—a huge improvement over satellite and cable boxes.
An even better solution would be to video mirror downloaded programs from your laptop or other device using the appropriate adapter. The iPad, iPhone, and Android phones each use between 3 and 6 watts, far less than any of the standard set-top boxes. (A standard desktop computer isn’t a good alternative. Even when idle and with the screen off, they use more than 30 watts [PDF].) Your Wi-Fi router adds another 5 watts to the equation, and your cable or DSL modem might tack on another 4—although you’d probably be running those regardless.
The other end of the equation is the energy consumed by the satellite and cable companies sending the signal to your box. Unfortunately, there are no good data on their power consumption. The Lantern huddled with some consultants in this field who feel that the satellite providers probably beat out cable, if we’re looking only at television. Cable providers have to power and maintain thousands of infrastructure boxes on street corners around the country. They have to lay underground cable from house to house. And there’s a lot of embedded energy in those cables, such as the copper mining. Solar-powered satellites don’t share those problems.
On the other hand, most households receive broadband Internet, which shares a lot of the same infrastructure as cable. Some satellite providers even deliver video on demand through the Internet.
This lack of clarity isn’t particularly significant, however, because household energy consumption is what really matters. There are more than 112 million households in the United States, with an average of 2.24 televisions per home. Approximately 116 million of those 250 million televisions have set-top boxes, which means a collective, continuous energy consumption of approximately 4 billion watts. If they all switched to a video-mirrored tablet, it could save the energy grid as much as 2.6 billion watts. By comparison, the Internet giant Google shocked the world in September when the company revealed that, worldwide, its data centers continuously draw 260 million watts. Their total consumption is an order of magnitude less than the energy that could be saved nationwide if everyone turned off their set-top boxes.
That doesn’t mean the cable and satellite companies are off the hook. They could make a lot of changes to decrease energy consumption. First, they could choose less-energy-hungry set-top boxes, since consumers have no real choice in the matter. (European boxes, according to the NRDC report, are smarter with energy management.)
The home DVR model is also terribly inefficient. Most people record many times more programming than they ever intend to watch. And the recording system that allows you to rewind live television runs all the time, whether or not the TV is on. That means the DVR’s hard drive is spinning round-the-clock, eating through kilowatts.
It would be far more efficient to convert DVR to a video-on-demand-type system, with the television providers hosting the data remotely. That way many people could share the same copy of a show. Unfortunately, legal complexities have gotten in the way of this relatively obvious solution. Content providers say that arrangement would be more like pay-per-view than home DVRs, so they should get another payment each time a household watches their shows. Until the big boys can settle this, your electricity meter is going to keep spinning out of control. ( slate.com )
New study challenges carbon benchmark - The ability of forests, plants and soil to suck carbon dioxide (CO2) from the air has been under-estimated, according to a study on Wednesday that challenges a benchmark for calculating the greenhouse-gas problem.
Like the sea, the land is a carbon "sink", or sponge, helping to absorb heat-trapping CO2 disgorged by the burning of fossil fuels.
A conventional estimate is that soil and vegetation take in roughly 120 billion tonnes, or gigatonnes, of carbon each year through the natural process of photosynthesis.
The new study, published in the science journal Nature, says the uptake could be 25-45 percent higher, to 150-175 gigatonnes per year.
Picture of the rainforest on the Costa Rican Pacific coast in 2005. The ability of forests, plants and soil to suck carbon dioxide (CO2) from the air has been under-estimated, according to a study on Wednesday that challenges a benchmark for calculating the greenhouse-gas problem. (AFP Photo/Mayela Lopez)
But relatively little of this extra carbon is likely to be stored permanently in the plant, say the researchers. Instead, it is likely to re-enter the atmosphere through plant respiration.
This will be a disappointment for those looking for some good news in the fight against climate change.
The more carbon is sequestered in the land, the less carbon enters the atmosphere, where it helps to trap heat from the Sun.
Lead researcher Lisa Welp, of the Scripps Institution of Oceanography in the University of California at San Diego, said figuring out the annual carbon uptake from the terrestrial biosphere had been one of the biggest problems in the emissions equation.
Scientists, though, were confident about current estimates for carbon sequestration in land and this was unlikely to change much in the light of the new findings, she said.
"More CO2 is passing through plants (than thought), not that it actually stays there very long," she said in email exchange with AFP.
"The extra CO2 taken up as photosynthesis is most likely returned right back to the atmosphere via respiration."
The research looked at isotopes, or variations, in the oxygen component of CO2, using a databank of atmospheric sampling going back three decades.
These isotopes are a chemical tag, indicating the kind of water the molecule has come into contact with.
The researchers looked at isotopes whose concentrations are linked to rainfall.
They were struck by a clear association between these isotopes and El Nino, the weather cycle which occurs in pendulum swings every few years or so.
The implication from this is that CO2 is swiftly cycled through land ecosystems, the researchers suggest. From that assumption comes the far higher estimate of annual carbon uptake. ( AFP )
Danger heats up for Australia's platypus - Global warming could shrink the habitat of Australia's duck-billed platypus by a third, researchers warned Friday, with hotter, drier temperatures threatening its survival.
A confusion of bird, mammal and reptile characteristics, the timid platypus is one of Australia's most cryptic creatures, feeding at night and living in deep waterside burrows to dodge predators such as foxes and eagles.
But its thick, watertight fur coat -- one of the key tools to ensuring its survival in the cool depths of rivers and waterholes -- could spell disaster in a warming climate, according to a new study from Melbourne's Monash University.
Using weather and platypus habitat data stretching back more than 100 years, researchers were able to map declines in particular populations in connection with droughts and heat events.
The team then extrapolated their findings across a range of climate change scenarios laid out by the government's science research agency, CSIRO, to model how global warming would affect the unusual native species.
Global warming could shrink the habitat of Australia's iconic duck-billed platypus by a third, researchers warned in Melbourne, with hotter drier temperatures threatening its survival
A confusion of bird, mammal and reptile characteristics, the timid platypus is one of Australia's most cryptic creatures, feeding at night and living in deep waterside burrows to dodge predators such as foxes and eagles
"Our worst case scenario at the moment suggested a one-third reduction in their suitable habitat," researcher Jenny Davis told AFP of the work published in the journal Global Change Biology.
Other human impacts, including land clearing and the damming of waterways for hydroelectric projects, had and would continue to diminish platypus homes, she added.
"Under a drying climate we'll be taking more water away from the environment because of our human needs, and predators are going to become more of an issue for (the) platypus," she said.
The most dire predictions suggested the platypus would disappear from Australia's mainland entirely, able only to live on Tasmania and the southern King and Kangaroo islands, said Davis.
Davis said the nocturnal creature already appeared to be responding to increases in Australia's average temperature, with certain populations receding from the 1960s, when a warming trend first became evident.
"Compared with 50 years ago some places have become too warm for them. Their habitat is shrinking," she said.
Classed as "common but vulnerable", the platypus is already extinct in the wild in South Australia state, and Davis said she feared it could meet a similar fate to the Tasmanian devil, whose numbers had dwindled rapidly.
"What could happen is that we could see a crash in an iconic animal and by the time that happens it's too late to do something about it," she said.
Platypus fur is finer and denser than that of a river otter or polar bear, and it has two layers: a long sleek outer and a woolly undercoat, ensuring it stays dry even when fully submerged in water.
Their average body temperature is 32 degrees Celsius (89 Fahrenheit) -- lower than most other mammals -- and they overheat rapidly when exposed to warm conditions out of the water.
Of most concern, however, is the drying up of waterways where they forage for aquatic invertebrates, with the platypus needing to eat about 30 percent of their own body weight every day to survive.
Davis said the creature's demise was "just another warning sign" of global warming's impact on Australia's unique wildlife. ( AFP )
